ORCID Profile
0000-0002-4423-1690
Current Organisation
University of Melbourne
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Veterinary Sciences | Parasitology | Other Biological Sciences | Biological Sciences not elsewhere classified | Gene Expression | Genetics | Environmental Biotechnology | Biodiscovery | Medical Parasitology | Genome Structure | Population And Ecological Genetics | Genetic Development (Incl. Sex Determination) | Infectious Agents | Infectious Diseases | Transgenesis | Sociobiology And Behavioural Ecology | Veterinary parasitology | Medicinal and Biomolecular Chemistry | Biological And Medical Chemistry | Epidemiology | Animal Production | Biotechnology Not Elsewhere Classified | Epidemiology | Veterinary sciences | Veterinary Parasitology | Bioinformatic methods development | Public Health And Health Services Not Elsewhere Classified | Animal Protection (Pests and Pathogens) | Molecular Evolution | Cell Development, Proliferation and Death | Bacteriology
ANZSRC Socio-Economic Objective (SEO)
Biological sciences | Expanding Knowledge in the Biological Sciences | Infectious diseases | Prevention—biologicals (e.g. vaccines) | Infectious Diseases | Ecosystem Adaptation to Climate Change | Land and water management | Animal Welfare | Control of pests and exotic species | Chemical sciences | Water services and utilities | Livestock | Expanding Knowledge in the Agricultural and Veterinary Sciences | Treatments (e.g. chemicals, antibiotics) |
Related Links
Publications
Secondary structure model for the ITS-2 precursor rRNA of strongyloid nematodes of equids: implications for phylogenetic inference
Publisher: Elsevier BV
Date: 12-1999
DOI: 10.1016/S0020-7519(99)00155-1
Abstract: In order to maximise the positional homology in the primary sequence alignment of the second internal transcribed spacer for 30 species of equine strongyloid nematodes, the secondary structures of the precursor ribosomal RNA were predicted using an approach combining an energy minimisation method and comparative sequence analysis. The results indicated that a common secondary structure model of the second internal transcribed spacer of these nematodes was maintained despite significant interspecific differences (2-56%) in primary sequences. The secondary structure model was then used to refine the primary second internal transcribed spacer sequence alignment. The 'manual' and 'structure' alignments were both subjected to phylogenetic analysis to compare the effect of using different sequence alignments on phylogenetic inference. The topologies of the phylogenetic trees inferred from the manual second internal transcribed spacer alignment were usually different to those derived from the structure second internal transcribed spacer alignment. The results suggested that the positional homology in the second internal transcribed spacer primary sequence alignment was maximised when the secondary structure model was taken into consideration.
Deep domain adversarial neural network for the deconvolution of cell type mixtures in tissue proteome profiling
Publisher: Springer Science and Business Media LLC
Date: 19-10-2023
A perspective on genomic-guided anthelmintic discovery and repurposing using Haemonchus contortus
Publisher: Elsevier BV
Date: 06-2016
DOI: 10.1016/J.MEEGID.2015.06.029
Abstract: High-throughput molecular and computer technologies have become instrumental for systems biological explorations of parasites. Investigating the genomes and transcriptomes of different developmental stages of parasitic nematodes can provide insights into gene expression, regulation and function in the parasite, which is a significant step toward understanding their biology as well as host interactions and disease. This article covers aspects of a talk given at the MEEGID XII conference in Thailand in 2014. Here, we refer to recent studies of the genomes and transcriptomes of socioeconomically important parasitic nematodes of animals provide an account of the barber's pole worm (Haemonchus contortus) and emerging drug resistance problems in this and related worms we also propose a genomic-guided drug discovery and repurposing approach, involving the prediction of the druggable genome, prioritization of drug targets, screening of compound libraries against H. contortus and, briefly, a hit-to-lead optimization approach. We conclude by indicating prospects that molecular tool kits for nematodes provide to the scientific community for future comparative genomic, genetic, proteomic, metabolomic, evolutionary, biological, ecological and epidemiological investigations, and as a basis for biotechnological outcomes and translation.
Molecular characterization of the Haemonchus contortus phosphoinositide-dependent protein kinase-1 gene (Hc-pdk-1)
Publisher: Springer Science and Business Media LLC
Date: 03-02-2016
Larval anisakid nematodes in teleost fishes from Lizard Island, northern Great Barrier Reef, Australia
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/MF12211
Abstract: A survey was undertaken to characterise larval anisakid nematodes present in teleosts at Lizard Island on the northern Great Barrier Reef. In total, 464 fish were examined from 32 families, 62 genera and 107 species. Anisakid nematodes were found in 46 (9.9%) of the fish examined. Infections in Atherinidae, Lethrinidae, Lutjanidae and Serranidae were moderately prevalent, with the intensities of infection ranging from 1 to 80 whereas in the Sphyraenidae and Scombridae, the prevalence of infection was very high, with intensities ranging from 1 to anisakids. A combined morphological and molecular-phylogenetic approach was employed to identify larval anisakid nematodes to species and/or genotypes. The nematodes examined were identified as Anisakis typica (three genotypes based on molecular characterisation), Terranova Types I (five genotypes) and II (five genotypes) and Hysterothylacium Types IV, V (four genotypes), VI and X. The findings of the present study provide some insights into the distribution of larval anisakid nematodes in coral-reef fishes and a basis for future investigations of anisakid populations in marine fishes.
The Rise and Fall of Human Oesophagostomiasis
Publisher: Elsevier
Date: 2010
A Portrait of the Transcriptome of the Neglected Trematode, Fasciola gigantica-Biological and Biotechnological Implications
Publisher: Public Library of Science (PLoS)
Date: 02-2011
Highly sensitive non-isotopic restriction endonuclease fingerprinting of nucleotide variability in the gp60 gene within Cryptosporidium species, genotypes and subgenotypes infective to humans, and its implications
Publisher: Wiley
Date: 05-2010
Abstract: The high-resolution analysis of genetic variation has major implications for the identification of parasites and micro-organisms to species and subspecies as well as for population genetic and epidemiological studies. In this study, we critically assessed the effectiveness of a PCR-based restriction endonuclease fingerprinting (REF) method for the detection of mutations in the 60 kDa glycoprotein gene (gp60) of Cryptosporidium, a genus of parasitic protists of major human and animal health importance globally. This gene displays substantial intraspecific variability in sequence, particularly in a TCA (perfect and imperfect) microsatellite region, is present as a single copy in the nuclear genome and is used widely as a marker in molecular epidemiological studies of Cryptosporidium hominis and C. parvum, the two predominant species that infect humans. The results of this study demonstrated an exquisite capacity of REF to detect nucleotide variability in the gp60 gene within each of the two species. The differentiation of genotypes/subgenotypes based on REF analysis was supported by targeted sequencing, allowing the detection of levels of variation as low as a single-nucleotide transversion for licons of approximately 1 kb in size. The high-throughput potential and relatively low-cost of REF make it a particularly useful tool for large-scale genetic analyses of C. hominis and C. parvum. REF could also be utilized for comparative surveys of genetic variability across large nuclear genomic regions. Such analyses of Cryptosporidium in clinical and environmental s les by REF have important implications for identifying sources of infection, modes of transmission and/or possible infectivity to humans, thus assisting in the surveillance and control of cryptosporidiosis. Given its excellent mutation detection capacity, REF should find broad applicability to various single-copy genes as well as a wide range of other protozoan and metazoan parasites.
The Mitochondrial Genome of Toxocara canis
Publisher: Public Library of Science (PLoS)
Date: 06-08-2008
Electrophoretic Analysis of Genetic Variability within Cryptosporidium parvum from Imported and Autochthonous Cases of Human Cryptosporidiosis in the United Kingdom
Publisher: American Society for Microbiology
Date: 05-2003
DOI: 10.1128/AEM.69.5.2719-2730.2003
Abstract: Cryptosporidium parvum oocyst DNA s les ( n = 184) from humans with cryptosporidiosis contracted during foreign travel or during outbreaks in the United Kingdom were characterized genetically and categorized by single-strand conformation polymorphism (SSCP)-based analysis of the small-subunit gene (pSSU) (∼300 bp) and second internal transcribed spacer (pITS-2) (∼230 bp) of nuclear ribosomal DNA. The two recognized genotypes (types 1 and 2) of C. parvum could be readily differentiated by a distinct electrophoretic shift in the pSSU SSCP profile, associated with a nucleotide difference of ∼1.3 to 1.7%. Of the 102 s les from cases contracted during foreign travel, 88 (86.3%) were identified as C. parvum type 1 and 14 (13.7%) were identified as type 2. For outbreak s les, unequivocal differentiation between type 1 ( n = 20 one child nursery outbreak) and type 2 ( n = 62 two waterborne outbreaks) was also achieved. Nucleotide variation in pITS-2 (both within and among s les representing each genotype) was substantially greater (10 to 13 different profiles for each genotype, relating to sequence differences of ∼1 to 42%) than that in pSSU. SSCP analysis of pITS-2 for all s les revealed that some profiles had a broad geographical distribution whereas others were restricted to particular locations, suggesting a link between some subgenotypes and the geographical origin or source. Comparative denaturing polyacrylamide gel electrophoretic analysis revealed the same genotypic identification and a similar subgenotypic classification of s les as SSCP analysis. The findings of this study, particularly the detection of intragenotypic variation by SSCP, should have significant diagnostic implications for investigating transmission patterns and the monitoring of outbreaks.
Classification of Mycoplasma synoviae strains using single-strand conformation polymorphism and high-resolution melting-curve analysis of the vlhA gene single-copy region
Publisher: Microbiology Society
Date: 08-2007
DOI: 10.1099/MIC.0.2006/005140-0
Abstract: Mycoplasma synoviae is an economically important pathogen of poultry worldwide, causing respiratory infection and synovitis in chickens and turkeys. Identification of M. synoviae isolates is of critical importance, particularly in countries in which poultry flocks are vaccinated with the live attenuated M. synoviae strain MS-H. Using oligonucleotide primers complementary to the single-copy conserved 5' end of the variable lipoprotein and haemagglutinin gene (vlhA), licons of approximately 400 bp were generated from 35 different M. synoviae strains/isolates from chickens and subjected to mutation scanning analysis. Analysis of the licons by single-strand conformation polymorphism (SSCP) revealed 10 distinct profiles (A-J). Sequencing of the licons representing these profiles revealed that each profile related to a unique sequence, some differing from each other by only one base-pair substitution. Comparative high-resolution melting (HRM) curve analysis of the licons using SYTO 9 green fluorescent dye also displayed profiles which were concordant with the same 10 SSCP profiles (A-J) and their sequences. For both mutation detection methods, the Australian M. synoviae strains represented one of the A, B, C or D profiles, while the USA strains represented one of the E, F, G, H, I or J profiles. The results presented in this study show that the PCR-based SSCP or HRM curve analyses of vlhA provide high-resolution mutation detection tools for the detection and identification of M. synoviae strains. In particular, the HRM curve analysis is a rapid and effective technique which can be performed in a single test tube in less than 2 h.
Mitochondrial genomes of parasitic nematodes – progress and perspectives
Publisher: Elsevier BV
Date: 02-2006
Abstract: Mitochondria are subcellular organelles in which oxidative phosphorylation and other important biochemical functions take place within the cell. Within these organelles is a mitochondrial (mt) genome, which is distinct from, but cooperates with, the nuclear genome of the cell. Studying mt genomes has implications for various fundamental areas, including mt biochemistry, physiology and molecular biology. Importantly, the mt genome is a rich source of markers for population genetic and systematic studies. To date, more than 696 mt genomes have been sequenced for a range of metazoan organisms. However, few of these are from parasitic nematodes, despite their socioeconomic importance and the need for fundamental investigations into areas such as nematode genetics, systematics and ecology. In this article, we review knowledge and recent progress in mt genomics of parasitic nematodes, summarize applications of mt gene markers to the study of population genetics, systematics, epidemiology and evolution of key nematodes, and highlight some prospects and opportunities for future research.
Enterocytozoon bieneusi genotypes in cats and dogs in Victoria, Australia
Publisher: Springer Science and Business Media LLC
Date: 08-08-2019
Molecular characterization of Thelastomatoidea (Nematoda: Oxyurida) from cockroaches in Australia
Publisher: Cambridge University Press (CUP)
Date: 27-03-2006
Hydatid disease in Western Australia: A novel approach to education and surveillance
Publisher: Elsevier BV
Date: 11-1993
DOI: 10.1016/0169-4758(93)90056-L
Abstract: Hydatid disease (echinococcosis) remains a public health and economic problem of global proportion. Treatment usually requires major surgery and the prognosis for some forms of the disease is poor. The variable transmission patterns exhibited by the causative agents of this complex zoonosis, and inadequate support both internationally and nationally, have resulted in the establishment of control c aigns that are usually organized and funded at a local level. Here, Andrew Thompson, Ian Robertson, Robin Gasser and Clare Constantine describe a novel, targeted c aign of education and surveillance that has recently been initiated in Western Australia, where a totally artificial cycle of transmission for Fchinococcus granulosus has been established as a result of human activity.
Corrigendum to “Toward next-generation sequencing of mitochondrial genomes — Focus on parasitic worms of animals and biotechnological implications” [Biotechnol. Adv. 28 (2010) 151–159]
Publisher: Elsevier BV
Date: 03-2010
Mitochondrial genomic comparison of Clonorchis sinensis from South Korea with other isolates of this species.
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.MEEGID.2017.02.015
Abstract: Clonorchiasis is a neglected tropical disease that affects >35 million people mainly in China, Vietnam, South Korea and some parts of Russia. The disease-causing agent, Clonorchis sinensis, is a liver fluke of humans and other piscivorous animals, and has a complex aquatic life cycle involving snails and fish intermediate hosts. Chronic infection in humans causes liver disease and associated complications including malignant bile duct cancer. Central to control and to understanding the epidemiology of this disease is knowledge of the specific identity of the causative agent as well as genetic variation within and among populations of this parasite. Although most published molecular studies seem to suggest that C. sinensis represents a single species and that genetic variation within the species is limited, karyotypic variation within C. sinensis among China, Korea (2n=56) and Russian Far East (2n=14) suggests that this taxon might contain sibling species. Here, we assessed and applied a deep sequencing-bioinformatic approach to sequence and define a reference mitochondrial (mt) genome for a particular isolate of C. sinensis from Korea (Cs-k2), to confirm its specific identity, and compared this mt genome with homologous data sets available for this species. Comparative analyses revealed consistency in the number and structure of genes as well as in the lengths of protein-coding genes, and limited genetic variation among isolates of C. sinensis. Phylogenetic analyses of amino acid sequences predicted from mt genes showed that representatives of C. sinensis clustered together, with absolute nodal support, to the exclusion of other liver fluke representatives, but sub-structuring within C. sinensis was not well supported. The plan now is to proceed with the sequencing, assembly and annotation of a high quality draft nuclear genome of this defined isolate (Cs-k2) as a basis for a detailed investigation of molecular variation within C. sinensis from disparate geographical locations in parts of Asia and to prospect for cryptic species.
Genetic variation in the mitochondrial cytochrome c oxidase subunit 1 within Progamotaenia festiva (Cestoda: Anoplocephalidae) from macropodid marsupials
Publisher: Cambridge University Press (CUP)
Date: 27-04-2007
DOI: 10.1017/S0031182007002752
Abstract: Genetic variation was examined in the anoplocephalid cestode Progamotaenia festiva , from Australian marsupials, in order to test the hypothesis that P. festiva , is a complex of sibling species and to assess the extent of host switching reported previously based on multilocus enzyme electrophoresis (MEE). Polymerase chain reaction (PCR)-based single-strand conformational polymorphism (SSCP) was used for the analysis of sequence variation in the cytochrome c oxidase subunit 1 ( cox1 ) gene among 179 specimens of P. festiva (identified based on morphology and predilection site in the host) from 13 different host species, followed by selective DNA sequencing. Fifty-three distinct sequence types (haplotypes) representing all specimens were defined. Phylogenetic analyses of these sequence data (utilizing maximum parsimony and neighbour-joining methods) revealed 12 distinct clades. Other heterologous species, P. ewersi and P. macropodis , were used as outgroups and the remaining bile-duct inhabiting species, P. diaphana and P. effigia , were included in the analysis for comparative purposes. The latter 2 species were nested within the clades representing P. festiva . Most clades of P. festiva identified were restricted to a single host species one clade primarily in Macropus robustus was also found in the related host species M. antilopinus in an area of host sympatry another clade occurring primarily in M. robustus occurred also in additional kangaroo species, M. rufus and M. dorsalis . High levels of genetic ergence, the existence of distinct clades and their occurrence in sympatry provide support for the hypothesis that P. festiva represents a complex of numerous species, most of which, but not all, are host specific. Three distinct clades of cestodes were found within a single host, M. robustus , but there was no evidence of within-host speciation.
First molecular characterization of Cryptosporidium and Giardia from bovines (Bos taurus and Bubalus bubalis) in Sri Lanka: unexpected absence of C. parvum from pre-weaned calves
Publisher: Springer Science and Business Media LLC
Date: 21-02-2014
Elucidating the transcriptome of Fasciola hepatica - A key to fundamental and biotechnological discoveries for a neglected parasite
Publisher: Elsevier BV
Date: 03-2010
DOI: 10.1016/J.BIOTECHADV.2009.12.003
Abstract: Liver flukes of animals are parasitic flatworms (Platyhelminthes: Digenea) of major socioeconomic importance in many countries. Key representatives, such as Fasciola hepatica and F. gigantica, cause "liver fluke disease" (= fascioliasis), which is of major animal health significance worldwide. In particular, F. hepatica is a leading cause of production losses to the livestock (mainly sheep and cattle) and meat industries due to clinical disease, reduced weight gain and milk production, and deaths. This parasite is also a major food-borne pathogen of humans throughout parts of the Middle East, Asia and South America. Currently, there is a significant focus on the development of new approaches for the prevention and control of fascioliasis in livestock. Recent technological advances in genomics and bioinformatics provide unique opportunities for the identification and prevalidation of drug targets and vaccines through a better understanding of the biology of F. hepatica and related species as well as their relationship with their hosts at the molecular level. Surprisingly, despite the widespread socioeconomic impact of fascioliasis, genomic datasets for F. hepatica are scant, limiting the molecular biological research of this parasite. The present article explores specifically the transcriptome of the adult stage of F. hepatica using an integrated genomic-bioinformatic platform. The analysis of the current data reveals numerous molecules of biological relevance, some of which are inferred to be involved in key biological processes or pathways that could serve as targets for new trematocidal drugs or vaccines. Improved insights into the transcriptome of F. hepatica should pave the way for future, comparative analysis of the transcriptomes of other developmental stages of this and related parasites, such as F. gigantica, cancer-causing flatworms (Clonorchis sinensis and Opisthorchis viverrini) and blood flukes (Schistosoma mansoni and S. japonicum). Prediction of the essentiality of genes and their products, molecular network connectivity of trematode genes as well as experimental exploration of function should also add value to the genomic discovery efforts in the future, focused on biotechnological outcomes.
Oriental theileriosis in dairy cows causes a significant milk production loss
Publisher: Springer Science and Business Media LLC
Date: 19-02-2014
Sexing schistosome larvae
Publisher: Elsevier BV
Date: 08-1992
DOI: 10.1016/0169-4758(92)90148-U
Abstract: Biological and immunological factors may influence changes in sex ratios at different points of the schistosome life cycle, resulting in the fact that female schistosomes are significantly outnumbered by males in chronic infections of snails and mammalian hosts. Analysis of this phenomenon has long been h ered by shortcomings in the methods used to determine sex ratios. Here, Robin Gasser describes recently developed molecular methods for sexing schistosome larvae. These have opened the way towards understanding why sex ratios become male biased and allow a proper assessment of its consequences in the epidemiology, diagnosis and pathology of infection.
Advancing the multi-disciplinarity of parasitology within the British Society for Parasitology: studies of host–parasite evolution in an ever-changing world
Publisher: Cambridge University Press (CUP)
Date: 06-09-2018
DOI: 10.1017/S0031182018001476
Abstract: The study of parasites typically crosses into other research disciplines and spans across erse scales, from molecular- to populational-levels, notwithstanding promoting an understanding of parasites set within evolutionary time. Today, the 2030 Sustainable Development Goals (SDGs) help frame much of contemporary parasitological research, since parasites can be found in all ecosystems, blighting human, animal and plant health. In recognition of the multi-disciplinary nature of parasitological research, the 2017 Autumn Symposium of the British Society for Parasitology was held in London to provide a forum for novel exchange across medical, veterinary and wildlife fields of study. Whilst the meeting was devoted to the topic of parasitism, it sought to foster mutualism, the antithesis perhaps of parasitism, by forging new academic connections and social networks to exchange novel ideas. The meeting also celebrated the longstanding career of Professor David Rollinson, FLS in the award of the International Federation for Tropical Medicine Medal for his efforts spanning 40 years of parasitological research. Indeed, David has done so much to explore and promote the fascinating biology of parasitism, as exemplified by the 15 manuscripts contained within this Special Issue.
Genetic markers for strongylid nematodes of livestock defined by PCR-based restriction analysis of spacer rDNA
Publisher: Elsevier BV
Date: 03-1998
DOI: 10.1016/S0001-706X(97)00105-8
Abstract: Twenty-four species of parasitic nematode (order Strongylida) from sheep, goats, cattle or pigs were characterised using a polymerase chain reaction-linked restriction fragment length polymorphism technique (PCR-RFLP). The ribosomal (r)DNA region spanning the first internal transcribed spacer (ITS-1), 5.8S rRNA gene and the second internal transcribed spacer (ITS-2) (designated ITS) was lified from genomic DNA by polymerase chain reaction (PCR), digested separately with four restriction endonucleases (RsaI, HinfI, DraI or NlaIII) and the fragments separated by agarose gel electrophoresis. The PCR products lified from all species appeared as a single band of approximately 870 bp in size, except for Ostertagia ostertagi whose product was approximately 1250 bp. The PCR-RFLP analysis of ITS revealed characteristic restriction patterns for all species, except for C. surnabada and C. oncophora which had identical patterns. The study demonstrated that ITS contains useful genetic markers for the identification of a range of strongylid nematodes of livestock. These markers should be of use in specific PCR assays for the identification of developmental stages of the parasites where morphological characters are unreliable.
Rapid sequencing of rDNA from single worms and eggs of parasitic helminths
Publisher: Oxford University Press (OUP)
Date: 1993
Exploration of extracellular vesicles from Ascaris suum provides evidence of parasite–host cross talk
Publisher: Wiley
Date: 14-02-2019
Impact of next-generation technologies on exploring socioeconomically important parasites and developing new interventions
Publisher: Springer New York
Date: 28-10-2014
DOI: 10.1007/978-1-4939-2004-4_31
Abstract: High-throughput molecular and computer technologies have become instrumental for systems biological explorations of pathogens, including parasites. For instance, investigations of the transcriptomes of different developmental stages of parasitic nematodes give insights into gene expression, regulation and function in a parasite, which is a significant step to understanding their biology, as well as interactions with their host(s) and disease. This chapter (1) gives a background on some key parasitic nematodes of socioeconomic importance, (2) describes sequencing and bioinformatic technologies for large-scale studies of the transcriptomes and genomes of these parasites, (3) provides some recent ex les of applications and (4) emphasizes the prospects of fundamental biological explorations of parasites using these technologies for the development of new interventions to combat parasitic diseases.
A survey of the intestinal transcriptomes of the hookworms, Necator americanus and Ancylostoma caninum, using tissues isolated by laser microdissection microscopy
Publisher: Elsevier BV
Date: 05-2006
DOI: 10.1016/J.IJPARA.2006.01.015
Abstract: The gastrointestinal tracts of multi-cellular blood-feeding parasites are targets for vaccines and drugs. Recently, recombinant vaccines that interrupt the digestion of blood in the hookworm gut have shown efficacy, so we explored the intestinal transcriptomes of the human and canine hookworms, Necator americanus and Ancylostoma caninum, respectively. We used Laser Microdissection Microscopy to dissect gut tissue from the parasites, extracted the RNA and generated cDNA libraries. A total of 480 expressed sequence tags were sequenced from each library and assembled into contigs, accounting for 268 N. americanus genes and 276 A. caninum genes. Only 17% of N. americanus and 36% of A. caninum contigs were assigned Gene Ontology classifications. Twenty-six (9.8%) N. americanus and 18 (6.5%) A. caninum contigs did not have homologues in any databases including dbEST-of these novel clones, seven N. americanus and three A. caninum contigs had Open Reading Frames with predicted secretory signal peptides. The most abundant transcripts corresponded to mRNAs encoding cholesterol-and fatty acid-binding proteins, C-type lectins, Activation-Associated Secretory Proteins, and proteases of different mechanistic classes, particularly astacin-like metallopeptidases. Expressed sequence tags corresponding to known and potential recombinant vaccines were identified and these included homologues of proteases, anti-clotting factors, defensins and integral membrane proteins involved in cell adhesion.
A molecular systematic framework for equine strongyles based on ribosomal DNA sequence data.
Publisher: Elsevier BV
Date: 2000
DOI: 10.1016/S0020-7519(99)00166-6
Abstract: In this study, molecular data sets were used to address the controversies relating to the systematics of strongyloid nematodes of equids utilising morphological data sets. DNA sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2) of ribosomal DNA were determined for 30 species of equine strongyles and the systematic relationships reconstructed using phenetic and phylogenetic tree-building methods. The molecular data provided support for the hypothesis that the genera with large subglobular buccal capsules are ancestral to those with small cylindrical buccal capsules, but did not provide support for the current ision of the subfamilies Strongylinae and Cyathostominae or for some taxonomic groupings (i.e. generic designations of species) within the Cyathostominea based on morphological data. Although not entirely concordant, the current molecular data provide a systematic framework for future studies of equine strongyles, which could be exploited in combination with new, phylogenetically informative morphological data sets.
Dideoxy fingerprinting: application to the genotyping of Echinococcus
Publisher: Elsevier BV
Date: 11-1998
DOI: 10.1016/S0020-7519(98)00126-X
Abstract: Dideoxy fingerprinting is an efficient method for the detection of sequence variation in PCR- lified DNA segments. It is a hybrid between single-strand conformation polymorphism and dideoxy sequencing, employing only one dideoxynucleotide in the sequencing reaction. Herein, we report the application of dideoxy fingerprinting to genetically type cestodes of the genus Echinococcus, utilising the mitochondrial cytochrome c oxidase subunit I as the gene sequence for analysis. All of the seven genotypes (G1, G4, G6, G8, O, V and M2) examined could be readily differentiated from one another by their characteristic and reproducible dideoxy fingerprinting profiles. Only subtle variation in profiles was detected among some of the eight isolates representing genotype G1, and no variation was detected between two s les of genotype G4 and of genotype M2. The capacity of dideoxy fingerprinting to detect all nucleotide variations over 150-250bp fragments indicates that it should be possible to distinguish among all of the genotypes of Echinococcus thus far described. Although employed herein to display sequence variation in the cytochrome c oxidase subunit I of Echinococcus, dideoxy fingerprinting could be used for the high-resolution analysis of nucleotide variations in other parasite genes, without the need for DNA sequencing. This has important implications for studying the genetic structure of parasite populations.
A practical Java tool for small-molecule compound appraisal
Publisher: Springer Science and Business Media LLC
Date: 16-06-2015
Single-strand conformation polymorphism-based analysis reveals genetic variation within Spirometra erinacei (Cestoda: Pseudophyllidea) from Australia
Publisher: Elsevier BV
Date: 04-2002
Specific and genotypic identification ofCryptosporidium from a broad range of host species by nonisotopic SSCP analysis of nuclear ribosomal DNA
Publisher: Wiley
Date: 08-2007
Abstract: The accurate identification of Cryptosporidium (Protozoa: Apicomplexa) species and genotypes is central to the understanding of the transmission and to the diagnosis and control of cryptosporidiosis. In this study, we demonstrate the effectiveness of nonisotopic SSCP analysis of a approximately 300 bp region of the small subunit (pSSU) of ribosomal DNA for the specific identification of and delineation among 18 different Cryptosporidium species and genotypes from a wide range of hosts. This mutation scanning approach allowed the rapid and reliable differentiation between species/genotypes differing by as little as 1.3% in the pSSU sequence, with the capacity to detect point mutations. The present findings confirm the usefulness of this tool for the rapid genetic screening of Cryptosporidium s les from any host species, providing a foundation for detailed systematic, epidemiological and ecological studies. Although applied herein to pSSU, this low cost approach should be applicable to a wide range of genetic loci for population genetic investigations of Cryptosporidium.
Improved insights into the transcriptomes of the human hookworm Necator americanus - Fundamental and biotechnological implications
Publisher: Elsevier BV
Date: 03-2009
DOI: 10.1016/J.BIOTECHADV.2008.10.002
Abstract: Hookworms of humans are blood-feeding parasitic nematodes of major socio-economic significance in a wide range of countries. They cause a neglected tropical disease (NTD) called "hookworm disease" (=necatoriasis and/or ancylostomiasis). Necator americanus is the most widely distributed hookworm of humans and is a leading cause of iron deficiency anaemia, which can cause physical and mental retardation and deaths in children as well as adverse maternal-foetal outcomes. Currently, there is a significant focus on the development of new approaches for the prevention and control of hookworms in humans. Technological advances are underpinning the discovery of drug and vaccine targets through insights into the molecular biology and genomics of these parasites and their relationship with the human host. In spite of the widespread socio-economic impacts of human necatoriasis, molecular datasets for N. americanus are scant, limiting progress in molecular research. The present article explores all currently available EST datasets for adult and larval stages of N. americanus using a semi-automated bioinformatic pipeline. In the current repertoire of molecules now available, some have been or are being considered as candidate vaccines against N. americanus. Among others, the most abundant sets of molecules relate to the pathogenesis-related protein (PRP) superfamily, comprising various members, such as the Ancylostoma-secreted or activation-associated proteins (ASPs) and the kunitz-type proteins, both of which are inferred to play key roles in the interplay between N. americanus and the human host. Understanding the molecular biology of these and other novel molecules discovered could have important implications for finding new ways of disrupting the pathways that they are involved in, and should facilitate the identification of new drug and vaccine targets. Also, the bioinformatic prediction of the essentiality of genes and gene products as well as molecular network connectivity of nematode-specific genes, together with sequencing by 454 technology, are likely to assist in the genomic discovery efforts in the very near future, to also underpin fundamental, molecular research of hookworms.
Biotechnological advances in the diagnosis of avian coccidiosis and the analysis of genetic variation in Eimeria
Publisher: Elsevier BV
Date: 11-2006
DOI: 10.1016/J.BIOTECHADV.2006.06.001
Abstract: Coccidiosis is an intestinal disease of chickens caused by various species of protozoan parasites within the genus Eimeria. This disease has a major economic impact to growers and to the poultry industry world-wide. The diagnosis and genetic characterization of the different species of Eimeria are central to the prevention, surveillance and control of coccidiosis, particularly now given the major problems with wide-spread resistance of Eimeria species against anticoccidial drugs (coccidiostats) and the residue problems associated with these compounds. While traditional methods have had major limitations in the specific diagnosis of coccidiosis, there have been significant advances in the development of molecular-diagnostic tools. The present article provides a background on coccidiosis, reviews the main molecular methods which have been used and describes recent advances in the establishment of polymerase chain reaction (PCR)-coupled electrophoretic approaches for the specific diagnosis of coccidiosis as well as the genetic characterization of species of Eimeria. These biotechnological advances are considered to represent a significant step toward the improved prevention and control of this important disease of poultry.
OGEE v3: Online GEne Essentiality database with increased coverage of organisms and human cell lines
Publisher: Oxford University Press (OUP)
Date: 21-10-2020
DOI: 10.1093/NAR/GKAA884
Abstract: OGEE is an Online GEne Essentiality database. Gene essentiality is not a static and binary property, rather a context-dependent and evolvable property in all forms of life. In OGEE we collect not only experimentally tested essential and non-essential genes, but also associated gene properties that contributes to gene essentiality. We tagged conditionally essential genes that show variable essentiality statuses across datasets to highlight complex interplays between gene functions and environmental/experimental perturbations. OGEE v3 contains gene essentiality datasets for 91 species almost doubled from 48 species in previous version. To accommodate recent advances on human cancer essential genes (as known as tumor dependency genes) that could serve as targets for cancer treatment and/or drug development, we expanded the collection of human essential genes from 16 cell lines in previous to 581. These human cancer cell lines were tested with high-throughput experiments such as CRISPR-Cas9 and RNAi in total, 150 of which were tested by both techniques. We also included factors known to contribute to gene essentiality for these cell lines, such as genomic mutation, methylation and gene expression, along with extensive graphical visualizations for ease of understanding of these factors. OGEE v3 can be accessible freely at v3.ogee.info.
Differences in the second internal transcribed spacer (ribosomal DNA) between five species of Trichostrongylus (Nematoda: Trichostrongylidae).
Publisher: Elsevier BV
Date: 1995
DOI: 10.1016/0020-7519(94)00085-3
Abstract: The second internal transcribed spacer (ITS-2) of the ribosomal DNA of 5 species of Trichostrongylus has been sequenced. The ITS-2 of the 5 species was 237 or 238 bases in length, and had a GC content of approximately 30%. No evidence of intraspecific variation was detected in the ITS-2 sequence of T. colubriformis, T. vitrinus or T. retortaeformis, irrespective of the life cycle stage examined. There was evidence, however, of variation at five positions in the ITS-2 sequence of T. vitrinus s les and at one position in T. axei, indicating intra-in idual variation in the sequence of different copies of the ribosomal DNA. Nonetheless, there were consistent sequence differences between the five Trichostrongylus species examined. The level of interspecific differences in nucleotide sequence was low (1.3-7.6%), with the species infecting birds (T. tenuis) being genetically more different to the four species found in mammals. Some of the nucleotide differences between species occurred at the recognition sites of endonucleases, which makes them of important diagnostic value for species identification. Also of significance are the recognition sites for several enzymes located within the regions of sequence homology for the five species of Trichostrongylus. These may prove useful in distinguishing between genera of trichostrongyle nematodes.
An Evaluation of Machine Learning Approaches for the Prediction of Essential Genes in Eukaryotes Using Protein Sequence-Derived Features
Publisher: Elsevier BV
Date: 2019
Differences in the second internal transcribed spacer of four species of Nematodirus (Nematoda: Molineidae).
Publisher: Elsevier BV
Date: 02-1998
DOI: 10.1016/S0020-7519(97)00150-1
Abstract: Genetic differences among Nematodirus spathiger, Nematodirus filicollis, Nematodirus helvetianus and Nematodirus battus in the nucleotide sequence of the second internal transcribed spacer (ITS-2) of ribosomal DNA ranged from 3.9 to 24.7%. Pairwise comparisons of their ITS-2 sequences indicated that the most genetically similar species were N. spathiger and N. helvetianus. N. battus was the most genetically distinct species, with differences ranging from 22.8 to 24.7% with respect to the other three species. Some of the nucleotide differences among species provided different endonuclease restriction sites that could be used in restriction fragment length polymorphism studies. The ITS-2 sequence data may prove useful in studies of the systematics of molineid nematodes.
Scanning for nucleotide variations in mitochondrial DNA fragments of Schistosoma japonicum by single-strand conformation polymorphism
Publisher: Cambridge University Press (CUP)
Date: 1999
DOI: 10.1017/S0031182098003527
Abstract: In this study, we employed a mutation scanning approach for the direct visual display of genetic variability in mitochondrial DNA (mtDNA) fragments within and among populations of Schistosoma japonicum from the People's Republic of China. Fragments of the NADH dehydrogenase 1 gene (ND1) and the cytochrome c oxidase subunit I (COI) were in idually lified from parasite DNA by polymerase chain reaction (PCR), denatured and subjected to single-strand conformation polymorphism (SSCP) analysis. Using ND1 and COI fragments, in iduals representing different genotypes could be readily identified based on characteristic and reproducible SSCP profiles. The results demonstrated the usefulness of SSCP for the direct visual display of low-level sequence variation in mtDNA of S. japonicum prior to DNA sequence analysis. This approach has important implications for studying the genetic structure and biology of S. japonicum populations, and for analysing the inheritance of mitochondrial DNA.
Oesophagostomum dentatum - Potential as a model for genomic studies of strongylid nematodes, with biotechnological prospects
Publisher: Elsevier BV
Date: 05-2007
DOI: 10.1016/J.BIOTECHADV.2007.01.008
Abstract: There are substantial gaps in the knowledge of the molecular processes of development and reproduction in parasitic nematodes, despite the fact that understanding such processes could lead to novel ways of treating and controlling parasitic diseases, through blocking or disrupting key biological pathways. Biotechnological advances through large-scale sequencing projects, approaches for the analysis of differential gene and protein expression and functional genomics (e.g., double-stranded RNA interference) now provide opportunities to investigate the molecular basis of developmental processes in some parasitic nematodes. The porcine nodule worm, Oesophagostomum dentatum (order Strongylida), may provide a platform for testing the function of genes from this and related nematodes, given that this species can be grown and maintained in culture in vitro for periods longer than other nematodes of the same order. In this article, we review relevant biological, biochemical and molecular biological and genomic information about O. dentatum and propose that the O. dentatum - pig system provides an attractive model for exploring molecular developmental and reproductive processes in strongylid nematodes, leading toward new intervention methods and biotechnological outcomes.
Human thelaziosis - A neglected parasitic disease of the eye
Publisher: American Society of Parasitologists
Date: 08-2006
DOI: 10.1645/GE-823R.1
Investigating the Role of RIO Protein Kinases in Caenorhabditis elegans
Publisher: Public Library of Science (PLoS)
Date: 17-02-2015
A hitchhiker's guide to expressed sequence tag (EST) analysis
Publisher: Oxford University Press (OUP)
Date: 26-05-2007
DOI: 10.1093/BIB/BBL015
Abstract: Expressed sequence tag (EST) sequencing projects are underway for numerous organisms, generating millions of short, single-pass nucleotide sequence reads, accumulating in EST databases. Extensive computational strategies have been developed to organize and analyse both small- and large-scale EST data for gene discovery, transcript and single nucleotide polymorphism analysis as well as functional annotation of putative gene products. We provide an overview of the significance of ESTs in the genomic era, their properties and the applications of ESTs. Methods adopted for each step of EST analysis by various research groups have been compared. Challenges that lie ahead in organizing and analysing the ever increasing EST data have also been identified. The most appropriate software tools for EST pre-processing, clustering and assembly, database matching and functional annotation have been compiled (available online from biolinfo.org/EST). We propose a road map for EST analysis to accelerate the effective analyses of EST data sets. An investigation of EST analysis platforms reveals that they all terminate prior to downstream functional annotation including gene ontologies, motif attern analysis and pathway mapping.
A first insight into the genotypes of Echinococcus granulosus from humans in Mongolia
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.MCP.2010.11.001
Abstract: Polymerase chain reaction (PCR)-based single-strand conformation polymorphism (SSCP) and targeted sequencing were employed to genetically classify Echinococcus granulosus cysts from humans from 12 provinces in Mongolia using two DNA loci, designated pcox-1 and pnad-1, within the mitochondrial cytochrome c oxidase subunit 1 (cox-1) and NADH dehydrogenase subunit 1 (nad-1) genes, respectively. SSCP analysis of pcox-1 and pnad-1 licons produced from genomic DNA s les from in idual E. granulosus cysts (n = 50) from in idual humans displayed four distinct electrophoretic profiles for each pcox-1 and pnad-1. The direct sequencing of selected licons representing each of these profiles defined four distinct sequence types for each locus, present in four different combinations (designated as haplotypes M1-M4) for all 50 cyst isolates. Phylogenetic analysis of concatenated sequence data for these four haplotypes, including well-defined reference sequences, inferred that 68% of the cyst isolates belonged to the G1-G3 complex of E. granulosus (or E. granulosus sensu stricto), whereas the remaining (32%) were linked to the G6-G10 complex (or Echinococcus canadensis). Humans infected with E. granulosus cysts of the G1-G3 complex originated mainly from the eastern regions of Mongolia, whereas those harbouring cysts of the G6-G10 complex were from the western part of this country. The present study provides a first glimpse of the genetic composition of E. granulosus from humans in Mongolia, and forms a foundation for future studies of the epidemiology and ecology of the parasite(s) in animals and humans in this and surrounding countries.
Detection of Breinlia sp. (Nematoda) in the Leadbeater's possum (Gymnobelideus leadbeateri)
Publisher: Elsevier BV
Date: 08-2021
Identification of Anthelmintic Bishomoscalarane Sesterterpenes from the Australian Marine Sponge Phyllospongia bergquistae and Structure Revision of Phyllolactones A–D
Publisher: American Chemical Society (ACS)
Date: 21-06-2022
DOI: 10.1021/ACS.JNATPROD.2C00229
Abstract: High-throughput screening of the NatureBank marine extract library (7616 s les) identified an extract derived from the Australian marine sponge
Molecular aspects of sexual development and reproduction in nematodes and schistosomes
Publisher: Elsevier
Date: 2001
DOI: 10.1016/S0065-308X(01)50031-7
Abstract: In contrast to the free-living nematode Caenorhabditis elegans, surprisingly little is known about the molecular aspects of reproduction in parasitic helminths. Investigations into such aspects would provide an improved understanding of the fundamentals of sexual differentiation, development, maturation and behaviour, as well as sex-specific genes and their expression. Such knowledge could lead to new means of parasite control by interfering with or disrupting one or more of these processes, which is particularly important given the emerging problems with genetic resistance in parasitic nematodes against anthelmintic drugs. This chapter brings together some relevant information on the sexual biology of C. elegans, summarizes studies of gender-specific expression in selected parasitic helminths of socio-economic significance, describes advanced molecular techniques for the analysis of gender-specific genes, and indicates the prospects for genomic research on reproductive processes and the implications thereof for controlling parasitic helminths.
President’s message
Publisher: Elsevier BV
Date: 10-2014
Seroprevalence estimates for toxocariasis in people worldwide: A systematic review and meta-analysis
Publisher: Public Library of Science (PLoS)
Date: 19-12-2019
A vacuolar-type proton (H+) translocating ATPase ? subunit encoded by the Hc-vha-6 gene of Haemonchus contortus
Publisher: Elsevier BV
Date: 08-2010
DOI: 10.1016/J.MCP.2010.03.002
Abstract: In the present study, a full-length cDNA (designated Hc-vha-6) inferred to encode an alpha subunit of a vacuolar-type proton translocating adenosine triphosphatase (V-ATPase) was isolated from the parasitic nematode Haemonchus contortus, and characterized. The transcript for Hc-vha-6 was detected in all developmental stages and both sexes of H. contortus. Elements, including two TATA box (TATAA), two inverted CAAT box (ATTGG), five E box (CANNTG) and six GATA as well as five inverse GATA (TTATC) transcription factor motifs, were identified in the non-coding region upstream of Hc-vha-6. The open reading frame (ORF) of 2601 nucleotides encoded a protein (Hc-VHA-6) of 866 amino acids and a molecular weight of approximately 98.7 kDa. Comparison with a published protein sequence for a homologue (VPH1P) from yeast showed that Hc-VHA-6 had nine transmembrane domains and the 14 essential amino acid residues associated with enzyme activity, assembly, intracellular and/or membrane targeting. Phylogenetic analyses of selected amino acid sequence data revealed Hc-VHA-6 to be most closely related to VHA-6 of Caenorhabditis elegans. A predictive network analysis inferred that vha-6 interacts with at least seven other genes encoding V-ATPase subunits and a small Rab GTPase. This study provides the first insight into a V-ATPase of parasitic nematodes and a sound basis for future functional genomic work.
Serine/threonine phosphatases in socioeconomically important parasitic nematodes—Prospects as novel drug targets?
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.BIOTECHADV.2010.08.008
Abstract: Little is known about the fundamental biology of parasitic nematodes (=roundworms) that cause serious diseases, affecting literally billions of animals and humans worldwide. Unlocking the biology of these neglected pathogens using modern technologies will yield crucial and profound knowledge of their molecular biology, and could lead to new treatment and control strategies. Supported by studies in the free-living nematode, Caenorhabditis elegans, some recent investigations have provided improved insights into selected protein phosphatases (PPs) of economically important parasitic nematodes (Strongylida). In the present article, we review this progress and assess the potential of serine/threonine phosphatase (STP) genes and/or their products as targets for new nematocidal drugs. Current information indicates that some small molecules, known to specifically inhibit PPs, might be developed as nematocides. For instance, some cantharidin analogues are known to display exquisite PP-inhibitor activity, which indicates that some of them could be designed and tailored to specifically inhibit selected STPs of nematodes. This information provides prospects for the discovery of an entirely novel class of nematocides, which is of paramount importance, given the serious problems linked to anthelmintic resistance in parasitic nematode populations of livestock, and has the potential to lead to significant biotechnological outcomes.
An RNA Interference Tool to Silence Genes in Sarcoptes scabiei Eggs
Publisher: MDPI AG
Date: 14-01-2022
DOI: 10.3390/IJMS23020873
Abstract: In a quest for new interventions against scabies—a highly significant skin disease of mammals, caused by a parasitic mite Sarcoptes scabiei—we are focusing on finding new intervention targets. RNA interference (RNAi) could be an efficient functional genomics approach to identify such targets. The RNAi pathway is present in S. scabiei and operational in the female adult mite, but other developmental stages have not been assessed. Identifying potential intervention targets in the egg stage is particularly important because current treatments do not kill this latter stage. Here, we established an RNAi tool to silence single-copy genes in S. scabiei eggs. Using sodium hypochlorite pre-treatment, we succeeded in rendering the eggshell permeable to dsRNA without affecting larval hatching. We optimised the treatment of eggs with gene-specific dsRNAs to three single-copy target genes (designated Ss-Cof, Ss-Ddp, and Ss-Nan) which significantly and repeatedly suppressed transcription by ~66.6%, 74.3%, and 84.1%, respectively. Although no phenotypic alterations were detected in dsRNA-treated eggs for Ss-Cof and Ss-Nan, the silencing of Ss-Ddp resulted in a 38% reduction of larval hatching. This RNAi method is expected to provide a useful tool for larger-scale functional genomic investigations for the identification of essential genes as potential drug targets.
Anoplocephala perfoliata of horses - Significant scope for further research, improved diagnosis and control
Publisher: Cambridge University Press (CUP)
Date: 08-02-2005
DOI: 10.1017/S0031182004007127
Abstract: Anoplocephala perfoliata is the commonest tapeworm parasite of horses and is incriminated as a significant cause of clinical disease (e.g., ileocaecal intussusception, caeco-caecal intussusception and/or caecal perforation), particularly in horses chronically infected with large numbers of worms. The high prevalence (~20–80%) of the parasite in some countries suggests an increased risk of clinical cases. In spite of research, there is still a paucity of information regarding the pathogenesis of the disease, the epidemiology of the parasite in different geographical regions and there are significant limitations with the diagnosis of infection. The present article provides an account of the biology, epidemiology and pathogenic effects of A. perfoliata , the diagnosis of infection and treatment. It highlights some gaps in knowledge of the parasite and the disease it causes, and suggests opportunities for future research and prospects for improved diagnosis, prevention and control.
Human toxocariasis – A look at a neglected disease through an epidemiological ‘prism’
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.MEEGID.2019.104002
Abstract: Toxocariasis, a disease caused by infection with larvae of Toxocara canis, T. cati and/or congeners, represents clinical syndromes in humans including visceral and ocular larva migrans, neurotoxocariasis and covert/common toxocariasis. It is reported to be one of the most widespread public health and economically important zoonotic parasitic infections that humans share with dogs, wild canids, including foxes, and possibly other mammals. Humans become infected by accidental ingestion of embryonated Toxocara eggs, or larvae from tissues from domestic or wild paratenic hosts. Most infections are asymptomatic, and human disease may go unnoticed, as clinical investigation is often not pursued and/or diagnostic testing not conducted. Sometimes toxocariasis can be associated with complications, such as allergic and/or neurological disorders, possibly including cognitive or developmental delays in children. There is no anti-toxocariasis vaccine, and chemotherapy in humans varies, depending on symptoms and location of larvae, and may include the administration of albendazole or mebendazole, together with anti-inflammatory corticosteroids. Some recent studies indicate that toxocariasis is having an increased, adverse impact on human health in some, particularly underprivileged, tropical and subtropical communities around the world. Although tens of millions of people, especially children, are expected to be exposed to, or infected with Toxocara species, there is limited precise epidemiological data or information on the relationship between seropositivity and disease (toxocariasis) on a global scale. To gain an improved insight into this area, the present article reviews salient clinical aspects of human toxocariasis and the epidemiology of this disease, with particular reference to seroprevalence, and discusses future research and approaches/measures to understand and prevent/control this socioeconomically important, yet neglected zoonosis.
The Proteome and Lipidome of Extracellular Vesicles from Haemonchus contortus to Underpin Explorations of Host–Parasite Cross–Talk
Publisher: MDPI AG
Date: 30-06-2023
Abstract: Many parasitic worms have a major adverse impact on human and animal populations worldwide due to the chronicity of their infections. There is a growing body of evidence indicating that extracellular vesicles (EVs) are intimately involved in modulating (suppressing) inflammatory/immune host responses and parasitism. As one of the most pathogenic nematodes of livestock animals, Haemonchus contortus is an ideal model system for EV exploration. Here, employing a multi-step enrichment process (in vitro culture, followed by ultracentrifugation, size exclusion and filtration), we enriched EVs from H. contortus and undertook the first comprehensive (qualitative and quantitative) multi-omic investigation of EV proteins and lipids using advanced liquid chromatography–mass spectrometry and informatics methods. We identified and quantified 561 proteins and 446 lipids in EVs and compared these molecules with those of adult worms. We identified unique molecules in EVs, such as proteins linked to lipid transportation and lipid species (i.e., sphingolipids) associated with signalling, indicating the involvement of these molecules in parasite-host cross-talk. This work provides a solid starting point to explore the functional roles of EV-specific proteins and lipids in modulating parasite-host cross-talk, and the prospect of finding ways of disrupting or interrupting this relationship to suppress or eliminate parasite infection.
Gene Content Evolution in the Arthropods
Publisher: Cold Spring Harbor Laboratory
Date: 04-08-2018
DOI: 10.1101/382945
Abstract: Arthropods comprise the largest and most erse phylum on Earth and play vital roles in nearly every ecosystem. Their ersity stems in part from variations on a conserved body plan, resulting from and recorded in adaptive changes in the genome. Dissection of the genomic record of sequence change enables broad questions regarding genome evolution to be addressed, even across hyper- erse taxa within arthropods. Using 76 whole genome sequences representing 21 orders spanning more than 500 million years of arthropod evolution, we document changes in gene and protein domain content and provide temporal and phylogenetic context for interpreting these innovations. We identify many novel gene families that arose early in the evolution of arthropods and during the ersification of insects into modern orders. We reveal unexpected variation in patterns of DNA methylation across arthropods and ex les of gene family and protein domain evolution coincident with the appearance of notable phenotypic and physiological adaptations such as flight, metamorphosis, sociality and chemoperception. These analyses demonstrate how large-scale comparative genomics can provide broad new insights into the genotype to phenotype map and generate testable hypotheses about the evolution of animal ersity.
Gene discovery for the carcinogenic human liver fluke, Opisthorchis viverrini
Publisher: Springer Science and Business Media LLC
Date: 22-06-2007
Abstract: Cholangiocarcinoma (CCA) – cancer of the bile ducts – is associated with chronic infection with the liver fluke, Opisthorchis viverrini . Despite being the only eukaryote that is designated as a 'class I carcinogen' by the International Agency for Research on Cancer, little is known about its genome. Approximately 5,000 randomly selected cDNAs from the adult stage of O. viverrini were characterized and accounted for 1,932 contigs, representing ~14% of the entire transcriptome, and, presently, the largest sequence dataset for any species of liver fluke. Twenty percent of contigs were assigned GO classifications. Abundantly represented protein families included those involved in physiological functions that are essential to parasitism, such as anaerobic respiration, reproduction, detoxification, surface maintenance and feeding. GO assignments were well conserved in relation to other parasitic flukes, however, some categories were over-represented in O. viverrini , such as structural and motor proteins. An assessment of evolutionary relationships showed that O. viverrini was more similar to other parasitic ( Clonorchis sinensis and Schistosoma japonicum ) than to free-living ( Schmidtea mediterranea ) flatworms, and 105 sequences had close homologues in both parasitic species but not in S. mediterranea . A total of 164 O. viverrini contigs contained ORFs with signal sequences, many of which were platyhelminth-specific. Ex les of convergent evolution between host and parasite secreted/membrane proteins were identified as were homologues of vaccine antigens from other helminths. Finally, ORFs representing secreted proteins with known roles in tumorigenesis were identified, and these might play roles in the pathogenesis of O. viverrini -induced CCA. This gene discovery effort for O. viverrini should expedite molecular studies of cholangiocarcinogenesis and accelerate research focused on developing new interventions, drugs and vaccines, to control O. viverrini and related flukes.
Screening of the ‘Pathogen Box’ identifies an approved pesticide with major anthelmintic activity against the barber's pole worm
Publisher: Elsevier BV
Date: 12-2016
Proteomic Analysis of the Excretory-Secretory Products from Larval Stages of Ascaris suum Reveals High Abundance of Glycosyl Hydrolases
Publisher: Public Library of Science (PLoS)
Date: 03-10-2013
Genetic blueprint of the zoonotic pathogen Toxocara canis
Publisher: Springer Science and Business Media LLC
Date: 04-02-2015
DOI: 10.1038/NCOMMS7145
Toward practical, DNA-based diagnostic methods for parasitic nematodes of livestock — Bionomic and biotechnological implications
Publisher: Elsevier BV
Date: 07-2008
DOI: 10.1016/J.BIOTECHADV.2008.03.003
Abstract: Parasitic nematodes of livestock have a major economic impact worldwide. In spite of the health problems caused by nematodes and advances toward the development of vaccines and new therapeutic agents against some of them, relatively limited attention has been paid to the need for improved, practical methods of diagnosis. Accurate diagnosis and genetic characterization of parasitic nematodes of livestock are central to their effective control, particularly given the current, serious problems with anthelmintic resistance in nematode populations. Traditional diagnostic techniques have considerable limitations, and there have been some advances toward the development of molecular-diagnostic tools. This article provides a brief account of the significance of parasitic nematodes (order Strongylida), reviews the techniques that have been evaluated or used for diagnosis and describes developments in polymerase chain reaction (PCR)-based methods for the specific diagnosis of nematode infection/s and the genetic characterisation of the causative agents. The advances made in recent years provide a solid foundation for the development of practical, highly sensitive and specific diagnostic tools for epidemiological investigations and for use in control programmes.
A Real-Time PCR Assay for the Diagnosis of Gastrointestinal Nematode Infections of Small Ruminants
Publisher: Springer New York
Date: 28-10-2014
DOI: 10.1007/978-1-4939-2004-4_10
Abstract: The diagnosis of gastrointestinal nematode infections in small ruminants is central to studying the biology and epidemiology of these parasites and underpins their control. Traditional methods of diagnosis are inaccurate, time-consuming and laborious. Here, we describe a step-by-step protocol for the molecular-based diagnosis of infections by real-time PCR.
New research tools for urogenital schistosomiasis
Publisher: Oxford University Press (OUP)
Date: 19-09-2015
Can New Digital Technologies Support Parasitology Teaching and Learning?
Publisher: Elsevier BV
Date: 07-2016
Abstract: Traditionally, parasitology courses have mostly been taught face-to-face on c us, but now digital technologies offer opportunities for teaching and learning. Here, we give a perspective on how new technologies might be used through student-centred teaching approaches. First, a snapshot of recent trends in the higher education is provided then, a brief account is given of how digital technologies [e.g., massive open online courses (MOOCs), flipped classroom (FC), games, quizzes, dedicated Facebook, and digital badges] might promote parasitology teaching and learning in digital learning environments. In our opinion, some of these digital technologies might be useful for competency-based, self-regulated, learner-centred teaching and learning in an online or blended teaching environment.
Searching for antigen B genes and their adaptive sites in distinct strains and species of the helminth Echinococcus
Publisher: Elsevier BV
Date: 07-2006
DOI: 10.1016/J.MEEGID.2005.07.003
Abstract: Twenty-seven PCR-derived antigen B (AgB) nucleotide sequences from four Echinococcus species (Echinococcus granulosus, Echinococcus multilocularis, Echinococcus oligarthrus and Echinococcus vogeli) were aligned with 78 already published sequences, to generate a maximum likelihood phylogeny of the AgB multigene family. The phylogenetic analysis confirms that the family is constituted by four groups of genes present in each one of the four species (AgB1, AgB2, AgB3 and AgB4), and suggests that it originated by ancient duplication events preceding speciation within the genus. AgB5 sequences, which had been formerly suggested to correspond to a putatively new AgB subunit, cluster with AgB3. Likelihood tests suggest that AgB gene evolution may have been driven by heterogeneous selection pressures acting on particular AgB1, AgB3 and AgB4 codons. No selection is detected in AgB2. We discuss implications of our findings in terms of AgB biology and its use as a diagnostic tool.
Selected α-pyrones from the plants Cryptocarya novoguineensis (Lauraceae) and Piper methysticum (Piperaceae) with activity against Haemonchus contortus in vitro
Publisher: Elsevier BV
Date: 04-2019
In silico analysis of expressed sequence tags from Trichostrongylus vitrinus (Nematoda): Comparison of the automated ESTExplorer workflow platform with conventional database searches
Publisher: Springer Science and Business Media LLC
Date: 02-2007
DOI: 10.1186/1471-2105-9-S1-S10
Abstract: The analysis of expressed sequence tags (EST) offers a rapid and cost effective approach to elucidate the transcriptome of an organism, but requires several computational methods for assembly and annotation. Researchers frequently analyse each step manually, which is laborious and time consuming. We have recently developed ESTExplorer, a semi-automated computational workflow system, in order to achieve the rapid analysis of EST datasets. In this study, we evaluated EST data analysis for the parasitic nematode Trichostrongylus vitrinus (order Strongylida) using ESTExplorer, compared with database matching alone. We functionally annotated 1776 ESTs obtained via suppressive-subtractive hybridisation from T. vitrinus , an important parasitic trichostrongylid of small ruminants. Cluster and comparative genomic analyses of the transcripts using ESTExplorer indicated that 290 (41%) sequences had homologues in Caenorhabditis elegans , 329 (42%) in parasitic nematodes, 202 (28%) in organisms other than nematodes, and 218 (31%) had no significant match to any sequence in the current databases. Of the C. elegans homologues, 90 were associated with 'non-wildtype' double-stranded RNA interference (RNAi) phenotypes, including embryonic lethality, maternal sterility, sterile progeny, larval arrest and slow growth. We could functionally classify 267 (38%) sequences using the Gene Ontologies (GO) and establish pathway associations for 230 (33%) sequences using the Kyoto Encyclopedia of Genes and Genomes (KEGG). Further examination of this EST dataset revealed a number of signalling molecules, proteases, protease inhibitors, enzymes, ion channels and immune-related genes. In addition, we identified 40 putative secreted proteins that could represent potential candidates for developing novel anthelmintics or vaccines. We further compared the automated EST sequence annotations, using ESTExplorer, with database search results for in idual T. vitrinus ESTs. ESTExplorer reliably and rapidly annotated 301 ESTs, with pathway and GO information, eliminating 60 low quality hits from database searches. We evaluated the efficacy of ESTExplorer in analysing EST data, and demonstrate that computational tools can be used to accelerate the process of gene discovery in EST sequencing projects. The present study has elucidated sets of relatively conserved and potentially novel genes for biological investigation, and the annotated EST set provides further insight into the molecular biology of T. vitrinus , towards the identification of novel drug targets.
Comparative Transcriptomic Exploration Reveals Unique Molecular Adaptations of Neuropathogenic Trichobilharzia to Invade and Parasitize Its Avian Definitive Host
Publisher: Public Library of Science (PLoS)
Date: 10-02-2016
Elucidating the ecology of bucephalid parasites using a mutation scanning approach.
Publisher: Elsevier BV
Date: 04-2004
Systematic analysis of insertions and deletions specific to nematode proteins and their proposed functional and evolutionary relevance
Publisher: Springer Science and Business Media LLC
Date: 28-01-2009
Abstract: Amino acid insertions and deletions in proteins are considered relatively rare events, and their associations with the evolution and adaptation of organisms are not yet understood. In this study, we undertook a systematic analysis of over 214,000 polypeptides from 32 nematode species and identified insertions and deletions unique to nematode proteins in more than 1000 families and provided indirect evidence that these alterations are linked to the evolution and adaptation of nematodes. Amino acid alterations in sequences of nematodes were identified by comparison with homologous sequences from a wide range of eukaryotic (metzoan) organisms. This comparison revealed that the proteins inferred from transcriptomic datasets for nematodes contained more deletions than insertions, and that the deletions tended to be larger in length than insertions, indicating a decreased size of the transcriptome of nematodes compared with other organisms. The present findings showed that this reduction is more pronounced in parasitic nematodes compared with the free-living nematodes of the genus Caenorhabditis . Consistent with a requirement for conservation in proteins involved in the processing of genetic information, fewer insertions and deletions were detected in such proteins. On the other hand, more insertions and deletions were recorded for proteins inferred to be involved in the endocrine and immune systems, suggesting a link with adaptation. Similarly, proteins involved in multiple cellular pathways tended to display more deletions and insertions than those involved in a single pathway. The number of insertions and deletions shared by a range of plant parasitic nematodes were higher for proteins involved in lipid metabolism and electron transport compared with other nematodes, suggesting an association between metabolic adaptation and parasitism in plant hosts. We also identified three sizable deletions from proteins found to be specific to and shared by parasitic nematodes, which, given their uniqueness, might serve as target candidates for drug design. This study illustrates the significance of using comparative genomics approaches to identify molecular elements unique to parasitic nematodes, which have adapted to a particular host organism and mode of existence during evolution. While the focus of this study was on nematodes, the approach has applicability to a wide range of other groups of organisms.
Mutation scanning analysis of Marteilia sydneyi populations from different geographical locations in eastern Australia
Publisher: Elsevier BV
Date: 04-2004
Evolutionary relationships of trichostrongyloid nematodes (Strongylida) inferred from ribosomal DNA sequence data.
Publisher: Elsevier BV
Date: 06-2001
Sexing single larval stages of Schistosoma mansoni by polymerase chain reaction
Publisher: Elsevier BV
Date: 08-1991
Novel High-Throughput Fluorescence-Based Assay for the Identification of Nematocidal Compounds That Target the Blood-Feeding Pathway
Publisher: MDPI AG
Date: 27-05-2022
DOI: 10.3390/PH15060669
Abstract: Hookworm infections cause a neglected tropical disease (NTD) affecting ~740 million people worldwide, principally those living in disadvantaged communities. Infections can cause high morbidity due to their impact on nutrient uptake and their need to feed on host blood, resulting in a loss of iron and protein, which can lead to severe anaemia and impaired cognitive development in children. Currently, only one drug, albendazole is efficient to treat hookworm infection and the scientific community fears the rise of resistant strains. As part of on-going efforts to control hookworm infections and its associated morbidities, new drugs are urgently needed. We focused on targeting the blood-feeding pathway, which is essential to the parasite survival and reproduction, using the laboratory hookworm model Nippostrongylus brasiliensis (a nematode of rodents with a similar life cycle to hookworms). We established an in vitro-drug screening assay based on a fluorescent-based measurement of parasite viability during blood-feeding to identify novel therapeutic targets. A first screen of a library of 2654 natural compounds identified four that caused decreased worm viability in a blood-feeding-dependent manner. This new screening assay has significant potential to accelerate the discovery of new drugs against hookworms.
PCR-based methods for identification of potentially zoonotic ascaridoid parasites of the dog, fox and cat
Publisher: Elsevier BV
Date: 11-1997
DOI: 10.1016/S0001-706X(97)00093-4
Abstract: Genomic DNA was extracted from ascaridoid nematodes collected from dogs, foxes and cats. A region spanning the second internal transcribed spacer (ITS-2) of the ribosomal DNA of each s le was lified by PCR. Representative ITS-2 products for each nematode species (Toxocara canis, Toxocara cati and Toxascaris leonina) were sequenced. Restriction sites were identified for use as genetic markers in a PCR-linked RFLP assay. The three species could be differentiated from each other and from other ascaridoids that may be found in human tissues by use of two endonucleases, HinfI and RsaI. Primers were designed to unique regions of the ITS-2 sequences of the three species for use in diagnostic PCR procedures and primer sets evaluated against panels of homologous and heterologous DNA s les. Results suggest that both methods are good candidates for further development for the detection and/or identification of ascaridoid larvae in human tissues.
Pharyngostrongylus thylogale n. sp. (Nematoda: Strongylida) from the stomachs of macropodid marsupials defined by morphological and molecular criteria.
Publisher: Springer Science and Business Media LLC
Date: 14-09-2016
DOI: 10.1007/S11230-016-9661-9
Abstract: Pharyngostrongylus thylogale n. sp. (Nematoda: Strongylida) is described from the stomach of the red-legged pademelon, Thylogale stigmatica (Gould) (Marsupialia: Macropodidae) from north-eastern Queensland and Papua New Guinea, having formerly been confused with P. iota Johnston & Mawson, 1939. Pharyngostrongylus thylogale n. sp. differs from all congeners in having 12 labial crown elements rather than eight or 16. Pharyngostrongylus iota was found in T. stigmatica, but only in southern Queensland and northern New South Wales, in the subspecies T. s. wilcoxi, compared with P. thylogale n. sp. which was found in T. s. stigmatica in northern Queensland and T. s. oriomo in Papua New Guinea. Differences in the sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA of P. thylogale n. sp. and ten congeners support the erection of the new species, and the validity of the morphospecies examined. However, results of the phylogenetic analyses of the molecular data also provide evidence for the existence of cryptic species within P. kappa Mawson, 1965. No obvious co-evolutionary relationships were observed between parasite species and their macropodid marsupial hosts.
Tetrahydroquinoxalines induce a lethal evisceration phenotype in Haemonchus contortus in vitro
Publisher: Elsevier BV
Date: 04-2019
Assessing the performance of multiplexed tandem PCR for the diagnosis of pathogenic genotypes of Theileria orientalis using pooled blood samples from cattle
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.MCP.2016.06.005
Abstract: Oriental theileriosis caused by multiple genotypes of Theileria orientalis is an important tick-borne disease of bovines. Here, we assessed the performance of an established multiplexed tandem PCR (MT-PCR) for the diagnosis of the two recognized, pathogenic genotypes (chitose and ikeda) of T. orientalis in cattle using pooled blood s les. We used a total of 265 cattle blood s les, which were ided into two groups according to previous MT-PCR results for in idual s les. S les in group 1 (n = 155) were from a herd with a relatively high prevalence of T. orientalis infection and those in group 2 (n = 110) were from four herds with a low prevalence. For group 1, 31 and 15 batches of five- and ten-pooled s les (selected at random), respectively, were formed. For group 2, 22 and 11 batches of five- and ten-pooled s les (selected at random), respectively, were formed. DNAs from in idual pooled s les in each batch and group were then tested by MT-PCR. For group 1, the apparent prevalences estimated using the 31 batches of five-pooled s les (97%) and 15 batches of ten-pooled s les (100%) were significantly higher compared with in idual s les (75%). For group 2, higher apparent prevalences (9% and 36%) were also recorded for the 22 and 11 batches of pooled s les, respectively, compared with in idual s les (7%). Overall, the average infection intensity recorded for the genotypes of chitose and ikeda were considerably lower in pooled compared with in idual s les. The diagnostic specificities of MT-PCR were estimated at 95% and 94%, respectively, when batches of five- and ten-pooled s les were tested, and 94% for in idual s les. The diagnostic sensitivity of this assay was estimated at 98% same for all in idual, five- and ten-pooled s les. This study shows that screening batches of five- and ten-pooled blood s les from cattle herds are similar to those obtained for in idual s les, and, importantly, that the reduced cost for the testing of pooled s les represents a considerable saving to herd managers.
Heartworm Genomics: Unprecedented Opportunities for Fundamental Molecular Insights and New Intervention Strategies
Publisher: Elsevier BV
Date: 11-2011
DOI: 10.1053/J.TCAM.2011.09.003
Abstract: Vector-borne diseases, including canine heartworm disease (CHWD), are of major socioeconomic and canine health importance worldwide. Although many studies have provided insights into CHWD, to date there has been limited study of fundamental molecular aspects of Dirofilaria immitis itself, its relationship with the canine host, its vectors, as well as the potential of drug resistance to emerge, using advanced -omic technologies. This article takes a prospective view of the benefits that advanced -omics technologies will have toward understanding D. immitis and CHWD. Tackling key biological questions using these technologies will provide a "systems biology" context and could lead to radically new intervention and management strategies against heartworm.
High resolution DNA fingerprinting by AFLP to study the genetic variation amongOesophagostomum bifurcum(Nematoda) from human and non-human primates from Ghana
Publisher: Cambridge University Press (CUP)
Date: 27-10-2004
DOI: 10.1017/S0031182004006249
Abstract: An AFLP approach was established to investigate genetic ersity within Oesophagostomum bifurcum (order Strongylida) from human and non-human primates. Evaluation of different combinations of restriction enzymes ( n =8) and primers ( n =29) demonstrated that the use of Hind III/ Bgl II digested templates and primers with the selective nucleotides +AG/+AC, respectively, was the most effective for the analysis of O. bifurcum DNA. A total of 63 O. bifurcum adults from human, Patas monkey, Mona monkey and Olive baboon hosts from different geographical regions in Ghana were subjected to analysis using this method. Cluster analysis revealed 4 genetically distinct groups, namely O. bifurcum from the Patas monkey (I), from the Mona monkey (II), from humans (III) and from the Olive baboon (IV). These findings were concordant with those achieved previously using RAPD analysis and supports population genetic substructuring within O. bifurcum according to host species. The results demonstrated the effectiveness of the present AFLP method for establishing genetic variation within O. bifurcum , and indicates its applicability to other parasitic nematodes of human and/or veterinary health importance.
Application of PCR-Based Tools to Explore Strongyloides Infection in People in Parts of Northern Australia.
Publisher: MDPI AG
Date: 08-12-2017
Applications of single-strand conformation polymorphism (SSCP) to taxonomy, diagnosis, population genetics and molecular evolution of parasitic nematodes
Publisher: Elsevier BV
Date: 11-2001
DOI: 10.1016/S0304-4017(01)00567-2
Abstract: The analysis of genetic variation in parasitic nematodes has important implications for studying aspects of taxonomy, diagnosis, population genetics, drug resistance and molecular evolution. This article highlights some applications of PCR-based single-strand conformation polymorphism (SSCP) for the analysis of sequence variation in in idual parasites (and their populations) to address some of these areas. It also describes the principles and advantages of SSCP, and provides some ex les for future applications in parasitology.
Mutation scanning analysis of microsatellite variability in the second internal transcribed spacer (precursor ribosomal RNA) for three species of Metastrongylus (Strongylida: Metastrongyloidea)
Publisher: Cambridge University Press (CUP)
Date: 02-2001
DOI: 10.1017/S0031182001007223
Abstract: This study investigated sequence variability in the second internal transcribed spacer of ribosomal DNA for 3 species of Metastrongylus (porcine lungworms). The ITS-2 region was lified by PCR from in iduals of M. elongatus, M. pudendotectus and M. salmi, and then subjected directly to single-strand conformation polymorphism analysis (SSCP), which allowed the direct display of sequence variation within and among in iduals representing each species. There were marked differences in SSCP profiles among species, making this approach useful for species identification. For in idual species, representative bands were excised from electrophoretic gels, re lified by PCR and subjected to direct sequencing. For all 3 taxa, variability in the ITS-2 was related chiefly to the presence of microsatellites. Eight different microsatellites were identified, namely (A)n, (TG)n, (TCG)n, (TA)n, (TATG)n, (G)n, (TACA)n and (T)n. Considerable variability in microsatellite repeat number (ranging from 1 to 23) was found among in idual nematodes of a species and between species. The microsatellites were located to specific stem or loop regions in the predicted ITS-2 precursor rRNA secondary structure. The results may suggest that slipped-strand mispairing in microsatellite regions contributes to sequence variability in the ITS-2 of Metastrongylus species under structural constraint as a consequence of microsatellite location in the precursor rRNA. Similar studies of the ITS-2 for a wide range of parasitic nematodes may lead to a better understanding of concerted evolution in these organisms.
Inadequate Differentiation of Theileria orientalis Genotypes buffeli and ikeda in a Multiplexed Tandem PCR (MT-PCR) Assay Using the p23 Ge
Publisher: American Society for Microbiology
Date: 02-2017
DOI: 10.1128/JCM.02017-16
Prevalence of antibodies to Neospora caninum in different canid populations
Publisher: JSTOR
Date: 12-1997
DOI: 10.2307/3284361
Identification of Nematodirus species (Nematoda: Molineidae) from wild ruminants in Italy using ribosomal DNA markers1Note: Nucleotide sequence data reported in this paper have been deposited in the G
Publisher: Elsevier BV
Date: 11-1999
DOI: 10.1016/S0020-7519(99)00123-X
Abstract: The sequence of the second internal transcribed spacer of ribosomal DNA was determined for four species of Nematodirus (Nematodirus rupicaprae, Nematodirus oiratianus, Nematodirus davtiani alpinus and Nematodirus europaeus) from roe deer or alpine chamois. The second internal transcribed spacer of the four species varied in length from 228 to 236 bp, and the G + C contents ranged from 41 to 44%. While no intraspecific sequence variation was detected among multiple s les representing three of the taxa, sequence differences of 5.9-9.7% were detected among the four species, Nematodirus davtiani alpinus and N. rupicaprae were genetically most similar (94.1%), followed by N. oiratianus, N. europaeus and N. rupicaprae (91.1-91.5%), whereas N. oiratianus was genetically most different from N. davtiani alpinus. The interspecific sequence differences were exploited for the delineation of the four species by PCR-based restriction fragment length polymorphism (using two enzymes) and single-strand conformation polymorphism. The results have implications for diagnosis, epidemiology and for studying the systematics of the Nematodirinae.
High Throughput Screening of the NatureBank ‘Marine Collection’ in a Haemonchus Bioassay Identifies Anthelmintic Activity in Extracts from a Range of Sponges from Australian Waters
Publisher: MDPI AG
Date: 27-09-2021
DOI: 10.3390/MOLECULES26195846
Abstract: Widespread resistance in parasitic nematodes to most classes of anthelmintic drugs demands the discovery and development of novel compounds with distinct mechanisms of action to complement strategic or integrated parasite control programs. Products from nature—which assume a erse ‘chemical space’—have significant potential as a source of anthelmintic compounds. In the present study, we screened a collection of extracts (n = 7616) derived from marine invertebrates s led from Australian waters in a high throughput bioassay for in vitro anti-parasitic activity against the barber’s pole worm (Haemonchus contortus)—an economically important parasitic nematode of livestock animals. In this high throughput screen (HTS), we identified 58 active extracts that reduced larval motility by ≥70% (at 90 h), equating to an overall ‘hit rate’ of ~0.8%. Of these 58 extracts, 16 also inhibited larval development by ≥80% (at 168 h) and/or induced ‘non-wild-type’ (abnormal) larval phenotypes with reference to ‘wild-type’ (normal) larvae not exposed to extract (negative controls). Most active extracts (54 of 58) originated from sponges, three from chordates (tunicates) and one from a coral these extracts represented 37 distinct species/taxa of 23 families. An analysis of s les by 1H NMR fingerprinting was utilised to dereplicate hits and to prioritise a set of 29 sponge s les for future chemical investigation. Overall, these results indicate that a range of sponge species from Australian waters represents a rich source of natural compounds with nematocidal or nematostatic properties. Our plan now is to focus on in-depth chemical investigations of the s le set prioritised herein.
PCR approach for the detection of Trypanosoma brucei and T. equiperdum and their differentiation from T. evansi based on maxicircle kinetoplast DNA
Publisher: Elsevier BV
Date: 02-2007
DOI: 10.1016/J.MCP.2006.03.009
Abstract: The goal of this study was to develop a PCR approach based on the sequence of maxicircle kinetoplast DNA (kDNA) of Trypanosoma brucei to distinguish T. brucei/T. equiperdum from T. evansi and to evaluate its diagnostic use for their detection in blood s les. Primers derived from the sequence of the maxicircle kDNA of T. brucei, encoding the NADH dehydrogenase subunit 5 (nad5) gene, were used to test the PCR- lification from T. brucei (including T. b. brucei and T. b. rhodesiense), T. equiperdum, T. evansi, T. vivax and T. congolense. A primer pair to a nuclear DNA region incorporated into a separate PCR was employed to control for the presence of lifiable genomic DNA (representing the subgenus Trypanozoon) in each s le subjected to the PCR. Products of approximately 395bp were lified from all T. brucei and T. equiperdum s les tested using the nad5-PCR, but not from T. evansi DNA s les or any of the control s les representing T. vivax, T. congolense, or host. The current PCR approach allows the rapid differentiation of T. brucei/T.equiperdum from T. evansi and can detect the equivalent of 20-25 cells of T. brucei or T. equiperdum in purified genomic DNA or infected blood s les.
Genome and transcriptome of the porcine whipworm Trichuris suis
Publisher: Springer Science and Business Media LLC
Date: 15-06-2014
DOI: 10.1038/NG.3012
Albendazole resistance induced in Ancylostoma ceylanicum is not due to single-nucleotide polymorphisms (SNPs) at codons 167, 198, or 200 of the beta-tubulin gene, indicating another resistance mechani
Publisher: Springer Science and Business Media LLC
Date: 29-01-2019
DOI: 10.1007/S00436-019-06218-9
Abstract: Mass drug administration has been implicated as the major cause of drug resistance in nematodes of ruminants. Single-nucleotide polymorphisms (SNPs) at codons 167, 198, and 200 of the beta-tubulin isotype 1 gene are associated with albendazole resistance mechanisms. Although drug resistance is suspected to occur in nematodes of the same order, at present, there is no evidence of a strong correlation between these canonical SNPs and albendazole resistance in hookworms. In the absence of a hookworm strain that is naturally resistant to albendazole, we produced an albendazole-resistant Ancylostoma ceylanicum strain by selective drug pressure. Restriction fragment length polymorphism-PCR (RFLP-PCR) was employed to identify the presence of SNPs previously associated with drug resistance in other nematodes. However, none of the benzimidazole resistance-associated SNPs known in other nematodes were found. A beta-tubulin isotype 1 gene mini-cDNA library was constructed to obtain the complete cDNA gene sequence for the analysis of the entire gene to identify distinct SNPs associated with resistance. Some SNPs were found, but the resulting sequences were not reproducibly detected among the different clones, preventing their association with the resistance mechanism. The parasitological and hematological parameters of the albendazole-resistant strain were characterized and compared to those of the sensitive strain. Although the albendazole-resistant strain was less adapted to its host, with fewer worms recovered, all other parameters analyzed were similar between both strains. The results of the present study indicate that the mechanism of albendazole resistance of the resistant strain described herein must differ from those that have previously been characterized. Thus, new mechanistic studies are needed in the future.
Genetic variation in the mitochondrial cytochrome c oxidase subunit 1 within three species of Progamotaenia (Cestoda: Anoplocephalidae) from macropodid marsupials.
Publisher: Cambridge University Press (CUP)
Date: 13-12-2005
DOI: 10.1017/S0031182004006377
Abstract: Sequence variation within 3 morphologically defined species of the anoplocephalid cestode genus Progamotaenia ( P. ewersi , P. macropodis and P. zschokkei ) was investigated using the cytochrome c oxidase subunit 1 gene. The magnitude of genetic variation detected within each morphospecies suggests that, in each instance, several cryptic species are present. Within P. ewersi , 5 genetically distict groups of cestodes were detected, 1 shared by Macropus robustus and M. parryi in Queensland, 1 in M. agilis from Queensland, 1 in Petrogale assimilis from Queensland, 1 in Macropus fuliginosus from South Australia and 1 in Wallabia bicolor from Victoria. In P. macropodis , cestodes from M. robustus from Queensland, Western Australia and the Northern Territory, M. parryi from Queensland and M. eugenii from South Australia were genetically distinct from those in Wallabia bicolor from Queensland and Victoria and from M. fuliginosus from South Australia. P. zschokkei consisted of a number of genetically distinct groups of cestodes, 1 in Lagorchestes conspicillatus and L. hirsutus from Queensland and the Northern Territory respectively, 1 in Petrogale herberti , P. assimilis and M. dorsalis from Queensland, 1 in Onychogalea fraenata from Queensland, 1 in M. agilis from Queensland and 1 in Thylogale stigmatica and T. thetis from Queensland. In general, genetic groups within each morphospecies were host specific and occurred predominantly in a particular macropodid host clade. Comparison of genetic relationships of cestodes with the phylogeny of their hosts revealed ex les of colonization ( P. zschokkei in M. agilis ) and of host switching ( P. zschokkei in M. dorsalis ).
Clonorchiasis: a key foodborne zoonosis in China
Publisher: Elsevier BV
Date: 2005
Making sense of genomes of parasitic worms: Tackling bioinformatic challenges.
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.BIOTECHADV.2016.03.001
Abstract: Billions of people and animals are infected with parasitic worms (helminths). Many of these worms cause diseases that have a major socioeconomic impact worldwide, and are challenging to control because existing treatment methods are often inadequate. There is, therefore, a need to work toward developing new intervention methods, built on a sound understanding of parasitic worms at molecular level, the relationships that they have with their animal hosts and/or the diseases that they cause. Decoding the genomes and transcriptomes of these parasites brings us a step closer to this goal. The key focus of this article is to critically review and discuss bioinformatic tools used for the assembly and annotation of these genomes and transcriptomes, as well as various post-genomic analyses of transcription profiles, biological pathways, synteny, phylogeny, biogeography and the prediction and prioritisation of drug target candidates. Bioinformatic pipelines implemented and established recently provide practical and efficient tools for the assembly and annotation of genomes of parasitic worms, and will be applicable to a wide range of other parasites and eukaryotic organisms. Future research will need to assess the utility of long-read sequence data sets for enhanced genomic assemblies, and develop improved algorithms for gene prediction and post-genomic analyses, to enable comprehensive systems biology explorations of parasitic organisms.
Harnessing the Toxocara Genome to Underpin Toxocariasis Research and New Interventions
Publisher: Elsevier
Date: 2016
DOI: 10.1016/BS.APAR.2015.12.001
Abstract: Parasitic worms, such as flatworms (platyhelminths) and roundworms (nematodes), cause substantial morbidity and mortality in animals and people globally. The ascaridoid nematode Toxocara canis is a zoonotic parasite of socioeconomic significance worldwide. In humans, this worm causes toxocariasis (disease) mainly in underprivileged communities in both the developed and developing worlds. While reasonably well studied from clinical and epidemiological perspectives, little is understood about the molecular biology of T. canis, its relationship with its hosts and the disease that it causes. However, a recent report of the draft genome and transcriptomes of T. canis should underpin many fundamental and applied research areas in the future. The present article gives a background on Toxocara and toxocariasis, a brief account of diagnostic approaches for specific identification and genetic analysis, and gives a perspective on the impact that the genome of T. canis and advanced molecular technologies could have on our understanding of the parasite and the diseases that it causes as well as the design of new and improved approaches for the diagnosis, treatment and control of toxocariasis.
Mutation scanning analysis of genetic variation within and among Echinococcus species: Implications and future prospects
Publisher: Wiley
Date: 30-05-2013
Abstract: Adult tapeworms of the genus Echinococcus (family Taeniidae) occur in the small intestines of carnivorous definitive hosts and are transmitted to particular intermediate mammalian hosts, in which they develop as fluid-filled larvae (cysts) in internal organs (usually lung and liver), causing the disease echinococcosis. Echinococcus species are of major medical importance and also cause losses to the meat and livestock industries, mainly due to the condemnation of infected offal. Decisions regarding the treatment and control of echinococcosis rely on the accurate identification of species and population variants (strains). Conventional, phenetic methods for specific identification have some significant limitations. Despite advances in the development of molecular tools, there has been limited application of mutation scanning methods to species of Echinococcus. Here, we briefly review key genetic markers used for the identification of Echinococcus species and techniques for the analysis of genetic variation within and among populations, and the diagnosis of echinococcosis. We also discuss the benefits of utilizing mutation scanning approaches to elucidate the population genetics and epidemiology of Echinococcus species. These benefits are likely to become more evident following the complete characterization of the genomes of E. granulosus and E. multilocularis.
Molecular and phylogenetic characterization of cytochromes c from Haemonchus contortus and Trichostrongylus vitrinus (Nematoda: Trichostrongylida)
Publisher: Elsevier BV
Date: 11-2008
DOI: 10.1016/J.GENE.2008.07.028
Abstract: Although cytochrome c genes (cyt c) and proteins (CYT C) have been relatively well studied in mammals, very little is known about them in parasitic helminths. In the present study, we investigated this group of molecules in Haemonchus contortus (barber's pole worm) and Trichostrongylus vitrinus (black scour worm), two parasitic nematodes of small ruminants. The cyt c gene (512 bp) of H. contortus had one intron and encoded a transcript of 345 nucleotides, whilst that of T. vitrinus (792 bp) had two introns and encoded a transcript of 360 nucleotides. The transcription of cyt c in T. vitrinus was substantially greater in adult males compared with females, although no such gender-enrichment was evident in adults of H. contortus. These findings were supported at the protein level by immunoblot analyses. The inferred proteins (designated Hc-CYT C and Tv-CYT C, respectively) shared nucleotide and amino acid identities of 78% and 85%, respectively. The alignment of these and other CYT C sequences from nematodes, flatworms, insects and mammals identified conserved motifs associated with CYT C oxidase- and reductase- as well as haem-binding. One residue (histidine-26) was conserved for mammals, whereas this residue was absent from all nematodes the functional significance of this difference is not yet known. Both phylogenetic analysis and protein modelling revealed that CYT C proteins of nematodes are structurally distinct from those of mammals and other organisms, suggesting their potential as targets for parasite intervention.
Genetic characterisation and taxonomy of species of Anisakis (Nematoda:Anisakidae) parasitic in Australian marine mammals
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/IS11019
Abstract: Three species of Anisakis from Australian marine mammals, including Anisakis brevispiculata, A. simplex C and A. pegreffii, are described and characterised genetically on the basis of sequence data for the first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear rDNA. Parasite specimens were collected from Delphinus delphis, Tursiops truntatus and Kogia sima in Australia. A. brevispiculata is reported for the first time in Australia. However, analyses of sequence data suggests that A. brevispiculata in Australia is genetically distinct from specimens considered to represent the same species from other parts of the world. Fourth larval and adult stages of A. pegreffii were found in dolphins. Assigning larvae to A. pegreffii was based on the ITS-1 and ITS-2 sequences. A description of these larvae also is provided. Furthermore, fourth-stage larvae of A. simplex C were found in Kogia sima. Alignments of ITS-1 and ITS-2 sequences for members of A. simplex sensu lato revealed that nucleotide differences in ITS-1 can be used to differentiate among members of A. simplex sensu lato. This study reinforces the use of a combined molecular and morphological approach for the specific identification of anisakid nematodes.
Using 454 technology for long-PCR based sequencing of the complete mitochondrial genome from single Haemonchus contortus (Nematoda)
Publisher: Springer Science and Business Media LLC
Date: 2008
Hookworm SCP/TAPS protein structure—A key to understanding host–parasite interactions and developing new interventions
Publisher: Elsevier BV
Date: 05-2012
DOI: 10.1016/J.BIOTECHADV.2011.11.002
Abstract: SCP/TAPS proteins are a erse family of molecules in eukaryotes, including parasites. Despite their abundant occurrence in parasite secretomes, very little is known about their functions in parasitic nematodes, including blood-feeding hookworms. Current information indicates that SCP/TAPS proteins (called Ancylostoma-secreted proteins, ASPs) of the canine hookworm, Ancylostoma caninum, represent at least three distinct groups of proteins. This information, combined with comparative modelling, indicates that all known ASPs have an equatorial groove that binds extended structures, such as peptides or glycans. To elucidate structure-function relationships, we explored the three-dimensional crystal structure of an ASP (called Ac-ASP-7), which is highly up-regulated in expression in the transition of A. caninum larvae from a free-living to a parasitic stage. The topology of the N-terminal domain is consistent with pathogenesis-related proteins, and the C-terminal extension that resembles the fold of the Hinge domain. By anomalous diffraction, we identified a new metal binding site in the C-terminal extension of the protein. Ac-ASP-7 is in a monomer-dimer equilibrium, and crystal-packing analysis identified a dimeric structure which might resemble the homo-dimer in solution. The dimer interaction interface includes a novel binding site for alent metal ions, and is proposed to serve as a binding site for proteins involved in the parasite-host interplay at the molecular level. Understanding this interplay and the integration of structural and functional data could lead to the design of new approaches for the control of parasitic diseases, with biotechnological outcomes.
The application of a polymerase chain reaction (PCR)-based capillary electrophoretic technique provides detailed insights into Eimeria populations in intensive poultry establishments
Publisher: Elsevier BV
Date: 08-2007
DOI: 10.1016/J.MCP.2007.03.001
Abstract: Intestinal coccidiosis, caused by one or multiple species of Eimeria (Protozoa: Apicomplexa), is one of the most important infectious diseases affecting chickens. In this study, we used a polymerase chain reaction (PCR)-based capillary electrophoresis (CE) approach to conduct an epidemiological survey of Eimeria species in seven Australian broiler flocks, varying in age from 18 to 42 days. We confirmed that all seven recognized Eimeria species of poultry were present. Eimeria acervulina and E. maxima were the most common, followed by E. mitis (i.e., 89%, 87% and 64% of chickens, respectively). E. praecox was present in 44% of birds, whereas E. brunetti and E. tenella were uncommon, being found in 36% and 26%, respectively. E. necatrix was rarely detected (10%). Even the least common species were present in more than 70% of sheds. The prevalence of in idual species was higher in older than in younger chickens. Most of the chickens s led were simultaneously infected with multiple Eimeria species (mean=3.6). The number of Eimeria oocysts excreted per gram of faeces reached a peak at 36 days of age, before declining to a considerably lower level by 42 days. As anticoccidial drugs were permanently withdrawn at 36 days, the decreasing Eimeria oocyst excretion rates indicated the development of protective immunity in the chickens. The present study showed that even healthy chickens usually harbour numerous species of Eimeria. The CE technique proved to be a time and cost-effective means of investigating the epidemiology of Eimeria in commercial establishments.
THE BANCROFT–MACKERRAS MEDALOF THE AUSTRALIAN SOCIETY FOR PARASITOLOGY Awarded to Robin B. Gasser
Publisher: Elsevier BV
Date: 07-2001
Ubiquitin-conjugating enzyme genes in Oesophagostomum dentatum
Publisher: Springer Science and Business Media LLC
Date: 04-03-2006
DOI: 10.1007/S00436-005-0111-X
Abstract: Full-length genes representing different isoforms of the ubiquitin-conjugating enzyme UBC-2 were isolated from Oesophagostomum dentatum, cloned and sequenced. The alignment of their sequences (designated Od-ubc-2.1 to Od-ubc-2.3) revealed nucleotide variation at three positions within the predicted open reading frame of 444 bp. Substitutions were at positions 141 (A G), 142 (A G) and 296 (T C). Both former substitutions resulted in amino acid changes from a glycine residue to an arginine residue, whereas the latter resulted in a change from isoleucine to threonine. Comparison of predicted OD-UBC-2 with UBC-2 (protein) homologues/orthologues from 12 other species representing nematodes, Drosophila melanogaster, Saccharomyces cerevisiae, mice and humans revealed identities between species varying from 77 to 100% at the amino acid level, and motifs associated with protein conformation and function were identified. While the function of a representative ubc-2 gene from O. dentatum could not be established in C. elegans, it is likely to play a key role in the catabolism of proteins and in the development of O. dentatum.
Using PCR-Based Sequencing to Diagnose Haycocknema perplexum Infection in Human Myositis Case, Australia.
Publisher: Centers for Disease Control and Prevention (CDC)
Date: 12-2018
Differentiation ofEntamoeba histolytica fromEntamoeba dispar by PCR-coupled nonisotopic SSCP analysis
Publisher: Wiley
Date: 11-2006
Abstract: Entamoeba histolytica is a pathogenic protozoan parasite, which causes amoebic colitis, dysentery and liver abscesses in humans. Since the cyst and small trophozoite stages of this parasite are indistinguishable by light microscopy from Entamoeba dispar (which is nonpathogenic), specific diagnosis is compromised. To overcome this limitation, a PCR-coupled SSCP approach, utilising a sequence difference of 4.6% in a short region ( approximately 173-174 bp) of the small subunit of nuclear ribosomal DNA, was evaluated for the differentiation of the two species of Entamoeba. Including a range of well-defined control DNA s les (n = 67) to evaluate the specificity of the PCR, 45 DNA s les representing E. histolytica and E. dispar from human faecal s les were tested by SSCP, and unequivocal delineation between the species was achieved. This SSCP approach should provide a practical tool for the specific diagnosis of E. histolytica in humans and for investigating its epidemiology.
Echinococcus granulosus: Antigenic proteins in oncospheres and on the surface of protoscoleces identified by serum antibodies from infected dogs
Publisher: Elsevier BV
Date: 05-1991
DOI: 10.1016/0034-5288(91)90135-B
Abstract: Proteins present in oncospheres and on the surface of living protoscoleces of Echinococcus granulosus were radioiodinated by the lodogen technique and immunoprecipitated with sera from dogs with E granulosus infection and several categories of control sera. Analysis of immunoprecipitates was performed using sodium dodecyl-sulphate polyacrylamide gel electrophoresis to identify antigenic protein components specific for E granulosus. Sera from dogs with E granulosus infection identified antigenic proteins of around Mr 37,000, 30,000 or 22,000 in oncospheres, and proteins of around Mr 70,000, 43,000, 36,000, 27,000 (triplet), 20,000 or 14,000 on the surface of protoscoleces. These antigens appear to be both species- and stage-specific and may be useful for serological discrimination between 'current' and 'recent past' prepatent and patent E granulosus infections in dogs.
Genome‐wide exploration reveals distinctive northern and southern variants of Clonorchis sinensis in the Far East
Publisher: Wiley
Date: 13-02-2023
Abstract: Clonorchis sinensis is a carcinogenic liver fluke that causes clonorchiasis—a neglected tropical disease (NTD) affecting ~35 million people worldwide. No vaccine is available, and chemotherapy relies on one anthelmintic, praziquantel. This parasite has a complex life history and is known to infect a range of species of intermediate (freshwater snails and fish) and definitive (piscivorous) hosts. Despite this biological complexity and the impact of this biocarcinogenic pathogen, there has been no previous study of molecular variation in this parasite on a genome‐wide scale. Here, we conducted the first extensive nuclear genomic exploration of C. sinensis in iduals ( n = 152) representing five distinct populations from mainland China, and one from Far East Russia, and revealed marked genetic variation within this species between “northern” and “southern” geographical regions. The discovery of this variation indicates the existence of biologically distinct variants within C. sinensis , which may have distinct epidemiology, pathogenicity and/or chemotherapic responsiveness. The detection of high heterozygosity within C. sinensis specimens suggests that this parasite has developed mechanisms to readily adapt to changing environments and/or host species during its life history/evolution. From an applied perspective, the identification of invariable genes could assist in finding new intervention targets in this parasite, given the major clinical relevance of clonorchiasis. From a technical perspective, the genomic‐informatic workflow established herein will be readily applicable to a wide range of other parasites that cause NTDs.
Recent Advances in Elucidating Nematode Moulting – Prospects of Using Oesophagostomum dentatum as a Model
Publisher: Elsevier
Date: 2016
DOI: 10.1016/BS.APAR.2015.09.001
Abstract: There are major gaps in our knowledge of many molecular biological processes that take place during the development of parasitic nematodes, in spite of the fact that understanding such processes could lead to new ways of treating and controlling parasitic diseases via the disruption of one or more biological pathways in the parasites. Progress in genomics, transcriptomics, proteomics and bioinformatics now provides unique opportunities to investigate the molecular basis of key developmental processes in parasitic nematodes. The porcine nodule worm, Oesophagostomum dentatum, represents a large order (Strongylida) of socioeconomically important nematodes, and provides a useful platform for exploring molecular developmental processes, particularly given that this nematode can be grown and maintained in culture in vitro for periods longer than most other nematodes of this order. In this article, we focus on the moulting process (ecdysis) in nematodes review recent advances in our understanding of molecular aspects of moulting in O. dentatum achieved by using integrated proteomic-bioinformatic tools and discuss key implications and future prospects for research in this area, also with respect to developing new anti-nematode interventions and biotechnological outcomes.
Cryptic Parasite Revealed. Improved Prospects for Treatment and Control of Human Cryptosporidiosis Through Advanced Technologies {star operator}
Publisher: Elsevier
Date: 2011
Contracaecum pyripapillatum n. sp. (Nematoda: Anisakidae) and a description of C. multipapillatum (von Drasche, 1882) from the Australian pelican, Pelecanus conspicillatus.
Publisher: Springer Science and Business Media LLC
Date: 08-08-2008
DOI: 10.1007/S00436-008-1088-Z
Abstract: A new species of nematode, Contracaecum pyripapillatum, is reported from the Australian pelican, Pelecanus conspicillatus. This species resembles Contracaecum multipapillatum which was found in the same host. These two species can be differentiated from one another based on the shape of the preanal papillae, being pyriform in C. pyripapillatum and circular in C. multipapillatum. Genetically, the two species differ in the sequences of first and second internal transcribed spacers (ITS-1 and ITS-2, respectively) of ribosomal DNA (rDNA). C. pyripapillatum and C. multipapillatum differed in the ITS-1 (443 bp in both species) and ITS-2 (between 231 and 233 bp) sequences by 3.4-3.8% and 6.0%, respectively. Based on previous allozyme and mtDNA datasets, genotypes of C. multipapillatum A, B, and C have been reported from Europe and USA. Therefore, C. multipapillatum from Australia has been designated as C. multipapillatum D. A morphological examination of these genotypes is necessary to determine whether they represent distinct species.
Characterisation of taeniid cestode species by PCR-RFLP of ITS2 ribosomal DNA
Publisher: Elsevier BV
Date: 03-1995
DOI: 10.1016/0001-706X(94)00085-F
Abstract: Seven species of taeniid cestode (Echinococcus granulosus. E. multilocularis, Taenia hydatigena, T. ovis, T. pisiformis, T. multiceps and T. serialis) were characterised using a polymerase chain reaction-based restriction fragment length polymorphism technique (PCR-RFLP). The second internal transcribed spacer of ribosomal DNA (ITS2) was lified from various geographical isolates of each of the seven species, digested separately with four restriction endonucleases and the fragments were separated by conventional agarose gel electrophoresis. PCR-RFLP produced characteristic patterns for each taeniid species examined. No variation in RFLP patterns was observed among different isolates of E. multilocularis and the species of Taenia, but distinct intraspecific variation was detected in E. granulosus. The present study indicates the usefulness of the PCR-RFLP of ITS2 for systematic, epidemiological and diagnostic purposes.
PCR-based identification and delineation of members within the Pseudorhabdosynochus lantauensis complex (Monogenea: Diplectanidae)
Publisher: Springer Science and Business Media LLC
Date: 22-10-2005
DOI: 10.1007/S00436-005-0011-0
Abstract: Molecular methods using genetic markers in the nuclear ribosomal DNA (rDNA) were established to identify and distinguish between two members within the Pseudorhabdosynochus lantauensis complex and two morphologically distinct congeners, Pseudorhabdosynochus epinepheli and Pseudorhabdosynochus coioidesis, from different marine fish species and various geographical origins. Supported by selective DNA sequencing, it was demonstrated that the polymerase chain reaction (PCR)-coupled single-strand conformation polymorphism analysis of the first internal transcribed spacer and restriction fragment length polymorphism analysis of a variable region (representing the D1-D3 domains) in the large subunit of rDNA achieved the identification and delineation of all four taxa examined. These PCR-based approaches provide useful complementary tools to traditional methods for the accurate identification of species within the genus Pseudorhabdosynochus (irrespective of developmental stage) and have major implications for studying the ecology, transmission, and population genetic structures of these and other related parasites and for the prevention and control of the diseases they cause.
Knocking down schistosomes – promise for lentiviral transduction in parasites
Publisher: Elsevier BV
Date: 07-2015
Abstract: Underpinned by major advances in our understanding of the genomes of schistosomes, progress in the development of functional genomic tools is providing unique prospects to gain insights into the intricacies of the biology of these blood flukes, their host relationships, and the diseases that they cause. This article reviews some key applications of double-stranded RNA interference (RNAi) in Schistosoma mansoni, appraises delivery systems for transgenesis and stable gene silencing, considers ways of increasing efficiency and specificity of gene silencing, and discusses the prospects of using a lentivirus delivery system for future functional genomic-phenomic explorations of schistosomes and other parasites. The ability to achieve effective and stable gene perturbation in parasites has major biological implications and could facilitate the development of new interventions.
Molecular investigation of Cryptosporidium in farmed chickens in Hubei Province, China, identifies 'zoonotic' subtypes of C. meleagridis.
Publisher: Springer Science and Business Media LLC
Date: 29-08-2018
Characterization of the Ca2+-Gated and Voltage-Dependent K+-Channel Slo-1 of Nematodes and Its Interaction with Emodepside
Publisher: Public Library of Science (PLoS)
Date: 18-12-2014
Progress on the transcriptomics of carcinogenic liver flukes of humans-Unique biological and biotechnological prospects
Publisher: Elsevier BV
Date: 11-2010
DOI: 10.1016/J.BIOTECHADV.2010.07.006
Abstract: Liver flukes, such as Clonorchis sinensis and Opisthorchis viverrini, are food-borne parasites that have a major impact on the health of humans and animals, particularly in Asia. However, the impact of C. sinensis and O. viverrini, in particular, is exacerbated in that these parasites can induce a malignant, untreatable cancer (cholangiocarcinoma, CCA) in chronically infected people. As a result, these flukes are classified as Group 1 carcinogens. Despite their substantial socio-economic importance, little is known about these parasites and their relationship with the definitive hosts at the molecular level. Here, we provide a background on these two carcinogenic flukes and review recent progress on characterizing their transcriptomes using next-generation technologies. We also describe the prospects that the transcriptomes of C. sinensis and O. viverrini provide as a resource for future -omic explorations and efforts to develop improved methods of intervention and control against these important pathogens and CCA, leading to biotechnological outcomes.
Genomic organization and expression analysis for hcstk, a serine/threonine protein kinase gene of Haemonchus contortus, and comparison with Caenorhabditis elegans par-1
Publisher: Elsevier BV
Date: 12-2004
DOI: 10.1016/J.GENE.2004.09.017
Abstract: The organization and expression of a putative serine/threonine kinase gene (designated hcstk), proposed to relate to a conserved eukaryotic signal transduction pathway, was characterized for the socio-economically important pathogen Haemonchus contortus (Nematoda). The entire hcstk gene is approximately 26.7 kb in size, has 26 exons and is inferred to produce multiple isoforms via alternative splicing in its N-terminal header and spacer domains. Comparison of hcstk with its Caenorhabditis elegans homologue, par-1, revealed major differences in genomic organization, exon number and inferred mRNA processing. The expression of hcstk transcripts was highest in the first- and late-fourth-stage larvae of the parasite compared with other developmental stages, somewhat distinct from par-1 in C. elegans. In spite of a substantial amino acid sequence identity in the functional domains between the predicted proteins HcSTK and PAR-1, overall, the findings suggest a unique functional role for each molecule.
Transcriptional Changes in the Hookworm, Ancylostoma caninum, during the Transition from a Free-Living to a Parasitic Larva
Publisher: Public Library of Science (PLoS)
Date: 09-01-2008
Techniques for the Diagnosis of Fasciola Infections in Animals
Publisher: Elsevier
Date: 2014
Enzyme characteristics of pathogen-specific trehalose-6-phosphate phosphatases
Publisher: Springer Science and Business Media LLC
Date: 17-05-2017
DOI: 10.1038/S41598-017-02220-2
Abstract: Owing to the key role of trehalose in pathogenic organisms, there has recently been growing interest in trehalose metabolism for therapeutic purposes. Trehalose-6-phosphate phosphatase (TPP) is a pivotal enzyme in the most prominent biosynthesis pathway (OtsAB). Here, we compare the enzyme characteristics of recombinant TPPs from five important nematode and bacterial pathogens, including three novel members of this protein family. Analysis of the kinetics of trehalose-6-phosphate hydrolysis reveals that all five enzymes display a burst-like kinetic behaviour which is characterised by a decrease of the enzymatic rate after the pre-steady state. The observed super-stoichiometric burst litudes can be explained by multiple global conformational changes in members of this enzyme family during substrate processing. In the search for specific TPP inhibitors, the trapping of the complex conformational transitions in TPPs during the catalytic cycle may present a worthwhile strategy to explore.
Male-enriched transcription of genes encoding ASPs and Kunitz-type protease inhibitors in Ancylostoma species
Publisher: Elsevier BV
Date: 12-2009
DOI: 10.1016/J.MCP.2009.07.004
Abstract: Various transcripts coding for proteins considered to be central to parasite-host interactions were identified previously as male-enriched in the hookworm Ancylostoma braziliense. Among these genes were an ASP-5-like homologue and a Kunitz-type protease inhibitor. The present study extends this previous work to investigate similar molecules in other hookworms (Ancylostomatidae). Specifically, partial cDNA sequences encoding three different ASP molecules and two different Kunitz-type protease inhibitors were isolated, and the differential transcription between adult male and female worms was compared by conventional and quantitative reverse transcription (RT)-PCR for three species, A. braziliense, Ancylostoma caninum and Ancylostoma ceylanicum. In accordance with previous findings, male-enriched transcription was observed for all molecules explored. Based on this information, it is hypothesized that adult males are responsible for producing proteins essential to the survival of hookworms inside the host and for supporting developmental and reproductive processes in female worms.
A comparison of the first internal transcribed spacer of ribosomal DNA in seven species of Trichostrongylus (Nematoda: Trichostrongylidae)
Publisher: Elsevier BV
Date: 08-1998
DOI: 10.1016/S0020-7519(98)00093-9
Abstract: The first internal transcribed spacer (ITS-1) of the ribosomal DNA of seven species of Trichostrongylus was sequenced. The length of ITS-1 in the different species varied from 387 to 390 bases. The G + C content of the ITS-1 sequences were approximately 42%. Little or no intraspecific variation was detected in the three species. Trichostrongylus axei, Trichostrongylus colubriformis and Trichostrongylus vitrinus, for which multiple isolates from different geographical regions were sequenced. In contrast, the level of ITS-1 sequence differences between species ranged from 1.3% to 5.7%. The greatest sequence differences were detected between T. tenuis, the parasite species which infects birds and the six species found in mammals. Some of the nucleotide differences occurred at sites corresponding to recognition sites for restriction endonucleases. These results are compared with previous data obtained for the second internal transcribed spacer (ITS-2). The ITS-1 data indicate that this region of rDNA may also be useful for systematic studies in trichostrongylid nematodes.
LIN-39 and the EGFR/RAS/MAPK pathway regulateC. elegansvulval morphogenesis via the VAB-23 zinc finger protein
Publisher: The Company of Biologists
Date: 11-2011
DOI: 10.1242/DEV.071951
Abstract: Morphogenesis represents a phase of development during which cell fates are executed. The conserved hox genes are key cell fate determinants during metazoan development, but their role in controlling organ morphogenesis is less understood. Here, we show that the C. elegans hox gene lin-39 regulates epidermal morphogenesis via its novel target, the essential zinc finger protein VAB-23. During the development of the vulva, the egg-laying organ of the hermaphrodite, the EGFR/RAS/MAPK signaling pathway activates, together with LIN-39 HOX, the expression of VAB-23 in the primary cell lineage to control the formation of the seven vulval toroids. VAB-23 regulates the formation of homotypic contacts between contralateral pairs of cells with the same sub-fates at the vulval midline by inducing smp-1 (semaphorin) transcription. In addition, VAB-23 prevents ectopic vulval cell fusions by negatively regulating expression of the fusogen eff-1. Thus, LIN-39 and the EGFR/RAS/MAPK signaling pathway, which specify cell fates earlier during vulval induction, continue to act during the subsequent phase of cell fate execution by regulating various aspects of epidermal morphogenesis. Vulval cell fate specification and execution are, therefore, tightly coupled processes.
Occurrence and abundance of anisakid nematode larvae in five species of fish from southern Australian waters
Publisher: Springer Science and Business Media LLC
Date: 06-11-2011
DOI: 10.1007/S00436-010-2134-1
Abstract: The aim of the present study was to conduct, in southern Australian waters, a preliminary epidemiological survey of five commercially significant species of fish (yellow-eye mullet, tiger flathead, sand flathead, pilchard and king fish) for infections with anisakid nematodes larvae using a combined morphological-molecular approach. With the exception of king fish, which was farmed and fed commercial pellets, all other species were infected with at least one species of anisakid nematode, with each in idual tiger flathead examined being infected. Five morphotypes, including Anisakis, Contracaecum type I and II and Hysterothylacium type IV and VIII, were defined genetically using mutation scanning and targeted sequencing of the second internal transcribed spacer of nuclear ribosomal DNA. The findings of the present study provide a basis for future investigations of the genetic composition of anisakid populations in a wide range of fish hosts in Australia and for assessing their public health significance.
Molecular separation of Oesophagostomum stephanostomum and Oesophagostomum bifurcum (Nematoda: Strongyloidea) from non-human primates1Note: Nucleotide sequences reported in this paper are available in
Publisher: Elsevier BV
Date: 07-1999
DOI: 10.1016/S0020-7519(99)00037-5
Abstract: The ITS-2 sequences for adult specimens of Oesophagostomum stephanostomum from the common chimpanzee and Oesophagostomum bifurcum from the Mona monkey were determined. For both species, the length and GC content of the ITS-2 sequences were 216 bp and 43%, respectively. While there was no unequivocal sequence difference among in idual worms representing each of the two species, five (2.3%) interspecific nucleotide differences were detected. These differences were associated with the presence of unique restriction sites in the ITS-2 sequence of 0. stephanostomum for multiple endonucleases of diagnostic value for the differentiation of the two taxa by restriction analysis. Pairwise comparisons of the ITS-2 sequences of O. stephanostomum and O. bifurcum with published ITS-2 sequences for five different congeners indicated that these species from the subgenus Conoweberia are closely related, in accordance with previous morphological studies.
An assessment of genetic variability in the mitochondrial cytochrome c oxidase subunit 1 gene of Cercopithifilaria sp. (Spirurida, Onchocercidae) from dog and Rhipicephalus sanguineus populations
Publisher: Elsevier BV
Date: 04-2012
DOI: 10.1016/J.MCP.2011.12.002
Abstract: This study investigates sequence variation in mitochondrial cytochrome c oxidase subunit 1 gene within Cercopithifilaria sp. recorded recently in Italy. Fourteen sequence types (haplotypes) were characterized for 163 (7.7%) licons from 2111 Genomic DNA s les prepared from skin s les from dogs and from Rhipicephalus sanguineus (ticks) from different geographical areas of the Mediterranean basin (i.e., Italy, Spain and Greece). The most prevalent sequence types represented haplotypes I (70.5%) and X (16.0%), followed by haplotype VIII (4.9%) and other 11 haplotypes (8.6%). Three haplotypes (II, V and VI) were found exclusively in ticks. The overall intraspecific nucleotide variation among pcox1 haplotypes ranged from 0.4 to 3.5% (mean = 1.6%), whereas a mean interspecific difference of 9.5% was detected as compared with other onchocercids. Phylogenetic analysis of the nucleotide sequence data showed a clustering of Cercopithifilaria sp. with the other Cercopithifilaria species (with strong statistical support) to the exclusion of other onchocercids. The number of haplotypes identified here might be explained by complex ecology and transmission patterns as well as the high mutation rate of mitochondrial DNA and/or inbreeding associated with hosts and their vectors.
Getting the most out of parasitic helminth transcriptomes using HelmDB: Implications for biology and biotechnology
Publisher: Elsevier BV
Date: 12-2013
DOI: 10.1016/J.BIOTECHADV.2012.12.004
Abstract: Compounded by a massive global food shortage, many parasitic diseases have a devastating, long-term impact on animal and human health and welfare worldwide. Parasitic helminths (worms) affect the health of billions of animals. Unlocking the systems biology of these neglected pathogens will underpin the design of new and improved interventions against them. Currently, the functional annotation of genomic and transcriptomic sequence data for socio-economically important parasitic worms relies almost exclusively on comparative bioinformatic analyses using model organism- and other databases. However, many genes and gene products of parasitic helminths (often >50%) cannot be annotated using this approach, because they are specific to parasites and/or do not have identifiable homologs in other organisms for which sequence data are available. This inability to fully annotate transcriptomes and predicted proteomes is a major challenge and constrains our understanding of the biology of parasites, interactions with their hosts and of parasitism and the pathogenesis of disease on a molecular level. In the present article, we compiled transcriptomic data sets of key, socioeconomically important parasitic helminths, and constructed and validated a curated database, called HelmDB (www.helmdb.org). We demonstrate how this database can be used effectively for the improvement of functional annotation by employing data integration and clustering. Importantly, HelmDB provides a practical and user-friendly toolkit for sequence browsing and comparative analyses among ergent helminth groups (including nematodes and trematodes), and should be readily adaptable and applicable to a wide range of other organisms. This web-based, integrative database should assist 'systems biology' studies of parasitic helminths, and the discovery and prioritization of novel drug and vaccine targets. This focus provides a pathway toward developing new and improved approaches for the treatment and control of parasitic diseases, with the potential for important biotechnological outcomes.
ITS-1 ribosomal DNA sequence variants are maintained in different species and strains of Echinococcus
Publisher: Elsevier BV
Date: 02-2000
DOI: 10.1016/S0020-7519(00)00002-3
Abstract: This study investigated sequence heterogeneity in the first internal transcribed spacer (ITS-1) of ribosomal DNA within and among species and strains of Echinococcus. Different ITS-1 sequence variants exist in Echinococcus granulosus and Echinococcus multilocularis, which represent at least four evolutionary lineages: (1) a sheep strain-lineage of E. granulosus, (2) a sister lineage of a cervid and camel E. granulosus ITS-1 variants, (3) a lineage including the ITS-1 variants representing horse, bovine and camel strains of E. granulosus, as well as variants from E. multilocularis, Echinococcus oligarthrus and Echinococcus vogeli and (4) a distinct lineage of ITS-1 variants including E. granulosus strains from sheep and cervid, and E. multilocularis. At least two of the species (E. granulosus and E. multilocularis) were paraphyletic for ITS-1. Divergent ITS-1 variants from these two species shared distinct evolutionary lineages. The sequence data provided evidence that at least two turnover mechanisms, namely slippage and unequal crossing over/transposition, have led to the ergence and maintenance of sequence variants in Echinococcus species and strains.
Nonisotopic single-strand conformation polymorphism analysis of sequence variability in ribosomal DNA expansion segments within the genusTrichinella (Nematoda: Adenophorea)
Publisher: Wiley
Date: 10-2004
Abstract: A nonisotopic single-strand conformation polymorphism (SSCP) approach was employed to 'fingerprint' sequence variability in the expansion segment 5 (ES5) of domain IV and the D3 domain of nuclear ribosomal DNA within and/or among isolates and in idual muscle (first-stage) larvae representing all currently recognized species/genotypes of Trichinella. In addition, phylogenetic analyses of the D3 sequence data set, employing three different tree-building algorithms, examined the relationships among all of them. These analyses showed strong support that the encapsulated species T. spiralis and T. nelsoni formed a group to the exclusion of the other encapsulated species T. britovi and its related genotypes Trichinella T8 and T9 and T. murrelli, and T. nativa and Trichinella T6, and strong support that T. nativa and Trichinella T6 grouped together. Also, these eight encapsulated members grouped to the exclusion of the nonencapsulated species T. papuae and T. zimbabwensis and the three representatives of T. pseudospiralis investigated. The findings showed that nonencapsulated species constitute a complex group which is distinct from the encapsulated species and supported the current hypothesis that encapsulated Trichinella group external to the nonencapsulated forms, in accordance with independent biological and biochemical data sets.
First survey of Cryptosporidium, Giardia and Enterocytozoon in diarrhoeic children from Wuhan, China.
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.MEEGID.2017.03.006
Abstract: Intestinal protozoan pathogens cause significant diarrhoeal diseases in children. However, to date, there has been limited genetic study of the intestinal pathogens Cryptosporidium, Giardia and Enterocytozoon in humans in China, with the exception of research in a small number of cities rovinces. In the present study, PCR-based tools were used to detect and characterise these protistan parasites from 500 children with a history of diarrhoea in Wuhan and environs, Hubei province, China. Genomic DNAs from faecal s les were screened for the particular protists by PCR utilising regions in the small subunit (SSU) of the nuclear ribosomal RNA, the 60kDa glycoprotein (gp60), the internal transcribed spacer of nuclear ribosomal DNA (ITS) and/or the triose phosphate isomerase (tpi) genes as markers. Cryptosporidium meleagridis subtype IIIb (10/500, 2.0%), Giardia duodenalis assemblage A (7/500, 1.4%) and Enterocytozoon bieneusi genotype D (1/500, 0.2%) were identified in small percentages of the 500 s les. No significant gender- or age-associated differences in the prevalence of Cryptosporidium and Giardia infections were found. Future studies might focus on the occurrence of these protists in children as well as animals, with an emphasis on Cryptosporidium meleagridis in pets and agriculturally important birds, in different parts of Hubei province.
Genomic resources for a unique, low-virulence Babesia taxon from China
Publisher: Springer Science and Business Media LLC
Date: 27-10-2016
Comparative bioinformatic analysis suggests that specific dauer-like signalling pathway components regulate Toxocara canis development and migration in the mammalian host
Publisher: Springer Science and Business Media LLC
Date: 14-01-2019
Mutation scanning‐based analysis of T heileria orientalis populations in cattle following an outbreak
Publisher: Wiley
Date: 07-2012
Abstract: Bovine theileriosis is a tick-borne disease caused by one or more hemoprotozoan parasites of the genus Theileria. In the past, Theileria infection in cattle in Australia was largely asymptomatic and recognized to be associated with Theileria buffeli. However, outbreaks of theileriosis have occurred in beef and dairy cattle in subtropical climatic regions (New South Wales) of Australia. There is also one published report of a recent theileriosis outbreak in a beef farm near Seymour in the southeastern state of Victoria. In order to gain an improved insight into the genetic composition of Theileria populations following this outbreak, we undertook herein an integrated PCR-coupled mutation scanning-sequencing-phylogenetic analysis of sequence variation in part of the major piroplasm surface protein (MPSP) gene within and among s les from cattle involved in the outbreak. Theileria DNA was detected in 89.4% of 94 cattle in the Seymour farm the genetic analysis showed that the ikeda and chitose genotypes representing the Theileria orientalis complex were detected in 75 and 4.8% of 84 infected cattle, respectively, and that mixed populations of these two genotypes were found in 20.2% of infected cattle. Given unpublished reports of a significant increase in the number of outbreaks in Victoria, future investigations should focus sharply on elucidating the epidemiology of Theileria to subvert the economic impact on the cattle industry in this state. Although used here to explore genetic variation within the T. orientalis complex in Australia, a mutation scanning-based approach has broad applicability to other species of Theileria in other countries.
Omega-1 knockdown in Schistosoma mansoni eggs by lentivirus transduction reduces granuloma size in vivo
Publisher: Springer Science and Business Media LLC
Date: 17-11-2014
DOI: 10.1038/NCOMMS6375
Abstract: Schistosomiasis, one of the most important neglected tropical diseases worldwide, is caused by flatworms (blood flukes or schistosomes) that live in the bloodstream of humans. The hepatointestinal form of this debilitating disease results from a chronic infection with Schistosoma mansoni or Schistosoma japonicum . No vaccine is available to prevent schistosomiasis, and treatment relies predominantly on the use of a single drug, praziquantel. In spite of considerable research effort over the years, very little is known about the complex in vivo events that lead to granuloma formation and other pathological changes during infection. Here we use, for the first time, a lentivirus-based transduction system to deliver microRNA-adapted short hairpin RNAs (shRNAmirs) into the parasite to silence and explore selected protein-encoding genes of S. mansoni implicated in the disease process. This gene-silencing system has potential to be used for functional genomic–phenomic studies of a range of socioeconomically important pathogens.
Hc-daf-2 encodes an insulin-like receptor kinase in the barber’s pole worm, Haemonchus contortus, and restores partial dauer regulation
Publisher: Elsevier BV
Date: 06-2014
Mutation scanning-based analysis of anisakid larvae from Sillago flindersi from Bass Strait, Australia
Publisher: Wiley
Date: 27-01-2012
Abstract: Anisakidosis is an important fish-borne disease caused by the larvae of anisakid nematodes, which affects humans and a range of other animals. The accurate identification of members of this nematode group is central to investigating the epidemiology of the parasites and in the surveillance and control of anisakidosis. It is now well known that morphological identification alone does not allow specific identification, particularly of larval stages. To better understand the epidemiology of anisakid nematodes in southern Australian fishes and the potential risks posed to human health, a survey of 50 specimens of the commercially important fish, Sillago flindersi, from Bass Strait, Australia was conducted. We characterised anisakid larvae by PCR-coupled mutation scanning, sequencing and phylogenetic analyses of the first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA. This study revealed that 92% of the S. flindersi examined were infected with anisakids (n=194), which were represented by seven genotypes. Phylogenetic analyses of the genotypes defined herein, together with reference sequence for Anisakis pegreffii and Hysterothylacium sp. from public databases (i.e. GenBank), revealed the presence of A. pegreffii (n=24), Hysterothylacium larval type IV (n=90) and Hysterothylacium larval type VIII (n=80) in S. flindersi. Thus, the PCR-coupled mutation scanning approach employed herein is an effective tool for the genetic characterisation of anisakid nematodes for diagnostic and analytical purposes (nucleotide sequences reported in this paper are available in the GenBank database under accession nos. JN631796-809).
Genomic-Bioinformatic Analysis of Transcripts Enriched in the Third-Stage Larva of the Parasitic Nematode Ascaris suum
Publisher: Public Library of Science (PLoS)
Date: 18-06-2008
Differences in a ribosomal DNA sequence of morphologically indistinguishable species within the Hypodontus macropi complex (Nematoda: Strongyloidea).
Publisher: Elsevier BV
Date: 05-1995
DOI: 10.1016/0020-7519(94)00171-J
Abstract: The nucleotide sequence of the second internal transcribed spacer (ITS-2) from ribosomal DNA has been determined for 3 members of the Hypodontus macropi species complex. Sequences were compared from nematodes collected from 3 species of Australian macropodid marsupial, Petrogale persephone, Macropus robustus robustus and Thylogale billardierii. The ITS-2 of each operational taxonomic unit ranged from 287 to 292 bases in length, and had a GC content of 36.6-40.1%. Differences in nucleotide sequence between nematodes from the different host species ranged from 25.0% to 28.3%. The data suggest that H. macropi from P. persephone represents a different species to those in M. r. robustus and T. billardierii. The unique feature of this study is that it represents a comparison of the ribosomal DNA sequences of nematode species which are morphologically indistinguishable but which have been demonstrated to be genetically distinct (i.e. cryptic) species based on electrophoretic data. The results also demonstrate further that morphological characters alone are often not adequate for species recognition. Differences between these 3 species of H. macropi in their recognition sites for restriction endonucleases, indicates that a PCR-RFLP approach could be used, in conjunction with allozyme electrophoresis, to establish how many species are present within the H. macropi complex.
DRfit: a Java tool for the analysis of discrete data from multi-well plate assays
Publisher: Springer Science and Business Media LLC
Date: 21-05-2019
Description of Cloacina atthis sp. nov. from the stomach of the euro (Macropus robustus) (Marsupialia: Macropodidae) from Western Australia based on morphological and molecular criteria
Publisher: Springer Science and Business Media LLC
Date: 16-07-2014
DOI: 10.1007/S00436-014-4019-1
Abstract: A new species of strongyloid nematode from the genus Cloacina (Chabertiidae: Cloacininae) is described from the stomach of the hill kangaroo or euro (Macropus robustus) (Marsupialia: Macropodidae) from Western Australia. Cloacina atthis sp. nov. was found only in euros from the Pilbara region in the northwest of Western Australia, in spite of extensive collecting of the same host species from around the Australian continent. C. atthis is most closely related to Cloacina clymene, a species found in the same host species but only in the eastern half of the continent the two species differ in minor morphological features (the shape of the wall of the buccal capsule, spicule lengths, the degree of sclerotisation of the gubernaculum and the shape of the vagina) as well as in differences in the internal transcribed spacers of ribosomal DNA. This study highlights the importance of using molecular methods when investigating the apparently disjunct distributions of strongyloid nematodes.
Practical High-Throughput Method to Screen Compounds for Anthelmintic Activity against Caenorhabditis elegans
Publisher: MDPI AG
Date: 08-07-2021
DOI: 10.3390/MOLECULES26144156
Abstract: In the present study, we established a practical and cost-effective high throughput screening assay, which relies on the measurement of the motility of Caenorhabditis elegans by infrared light-interference. Using this assay, we screened 14,400 small molecules from the “HitFinder” library (Maybridge), achieving a hit rate of 0.3%. We identified small molecules that reproducibly inhibited the motility of C. elegans (young adults) and assessed dose relationships for a subset of compounds. Future work will critically evaluate the potential of some of these hits as candidates for subsequent optimisation or repurposing as nematocides or nematostats. This high throughput screening assay has the advantage over many previous assays in that it is cost- and time-effective to carry out and achieves a markedly higher throughput (~10,000 compounds per week) therefore, it is suited to the screening of libraries of tens to hundreds of thousands of compounds for subsequent evaluation and development. The present phenotypic whole-worm assay should be readily adaptable to a range of socioeconomically important parasitic nematodes of humans and animals, depending on their dimensions and motility characteristics in vitro, for the discovery of new anthelmintic candidates. This focus is particularly important, given the widespread problems associated with drug resistance in many parasitic worms of livestock animals globally.
Diversity in the intrinsic apoptosis pathway of nematodes
Publisher: Springer Science and Business Media LLC
Date: 28-08-2020
DOI: 10.1038/S42003-020-01208-5
Abstract: Early studies of the free-living nematode C. elegans informed us how BCL-2-regulated apoptosis in humans is regulated. However, subsequent studies showed C. elegans apoptosis has several unique features compared with human apoptosis. To date, there has been no detailed analysis of apoptosis regulators in nematodes other than C. elegans . Here, we discovered BCL-2 orthologues in 89 free-living and parasitic nematode taxa representing four evolutionary clades (I, III, IV and V). Unlike in C. elegans , 15 species possess multiple (two to five) BCL-2-like proteins, and some do not have any recognisable BCL-2 sequences. Functional studies provided no evidence that BAX/BAK proteins have evolved in nematodes, and structural studies of a BCL-2 protein from the basal clade I revealed it lacks a functionally important feature of the C. elegans orthologue. Clade I CED-4/APAF-1 proteins also possess WD40-repeat sequences associated with apoptosome assembly, not present in C. elegans , or other nematode taxa studied.
Semi-nested PCR for the specific detection of Habronema microstoma or Habronema muscae DNA in horse faeces
Publisher: Cambridge University Press (CUP)
Date: 18-11-2004
DOI: 10.1017/S0031182004006122
Abstract: Habronema microstoma and Habronema muscae (Spirurida: Habronematidae) are parasitic nematodes which infect the stomach and/or skin of equids. The accurate diagnosis of gastric habronemosis is central to studying its epidemiology, but data on its distribution and prevalence are lacking, mainly due to the limitations of clinical and coprological diagnosis in live horses. To overcome this constraint, a two-step, semi-nested PCR-based assay was validated (utilizing genetic markers in the nuclear ribosomal DNA) for the specific lification of H. microstoma or H. muscae DNA from the faeces from horses ( n =46) whose gastrointestinal parasite status had been determined at autopsy and whose faeces were examined previously using a conventional parasitological approach. Of these horses examined at autopsy, some harboured adults of either H. microstoma ( n =19) or H. muscae ( n =4), and others ( n =7) harboured both species. Most of them were also infected with other parasites, including strongylid nematodes (subfamilies Cyathostominae and Strongylinae), bots and/or cestodes there was no evidence of metazoan parasites in 2 horses. Larvated spirurid eggs were detected in the faeces of 1 of the 30 horses (3·3%) shown to be infected with Habronema at autopsy. For this set of 46 s les, the PCR assay achieved a diagnostic specificity of 100% and a sensitivity of ~97% (being able to specifically detect as little as ~0·02 fg of Habronema DNA). The specificity of the assay was also tested using a panel of control DNA s les representing horse, the gastric spirurid Draschia megastoma and 26 other species of parasites from the alimentary tract of the horse. H. microstoma , H. muscae and D. megastoma could be readily differentiated from one another based on the sizes of their specific licons in the PCR. The results of this study showed that the performance of the PCR for the diagnosis of gastric habronemosis was similar to that of autopsy but substantially better than the traditional coprological examination procedure used. The ability to specifically diagnose gastric habronemosis in equids should have important implications for investigating the epidemiology and ecology of H. microstoma and H. muscae .
Acceleration versus heart rate for estimating energy expenditure and speed during locomotion in animals: Tests with an easy model species, Homo sapiens
Publisher: Elsevier BV
Date: 05-2008
DOI: 10.1016/J.ZOOL.2007.07.011
Abstract: An important element in the measurement of energy budgets of free-living animals is the estimation of energy costs during locomotion. Using humans as a particularly tractable model species, we conducted treadmill experiments to test the validity of tri-axial accelerometry loggers, designed for use with animals in the field, to estimate rate of oxygen consumption (VO2: an indirect measure of metabolic rate) and speed during locomotion. The predictive power of overall dynamic body acceleration (ODBA) obtained from loggers attached to different parts of the body was compared to that of heart rate (fH). When subject identity was included in the statistical analysis, ODBA was a good, though slightly poorer, predictor of VO2 and speed during locomotion on the flat (mean of two-part regressions: R2=0.91 and 0.91, from a logger placed on the neck) and VO2 during gradient walking (single regression: R2=0.77 from a logger placed on the upper back) than was fH (R2=0.96, 0.94, 0.86, respectively). For locomotion on the flat, ODBA was still a good predictor when subject identity was replaced by subject mass and height (morphometrics typically obtainable from animals in the field R2=0.92 and 0.89) and a slightly better overall predictor than fH (R2=0.92 and 0.85). For gradient walking, ODBA predicted VO2 more accurately than before (R2=0.83) and considerably better than did fH (R2=0.77). ODBA and fH combined were the most powerful predictor of VO2 and speed during locomotion. However, ODBA alone appears to be a good predictor and suitable for use in the field in particular, given that accelerometry traces also provide information on the timing, frequency and duration of locomotion events, and also the gait being used.
Crystal structure and immunological properties of the first annexin from Schistosoma mansoni: Insights into the structural integrity of the schistosomal tegument
Publisher: Wiley
Date: 15-01-2014
DOI: 10.1111/FEBS.12700
Abstract: Schistosomiasis is a major parasitic disease of humans, second only to malaria in its global impact. The disease is caused by digenean trematodes that infest the vasculature of their human hosts. These flukes are limited externally by a body wall composed of a syncytial epithelium, the apical surface membrane of which is a parasitism-adapted dual membrane complex. Annexins are thought to be of integral importance for the stability of this apical membrane system. Here, we present the first structural and immunobiochemical characterization of an annexin from Schistosoma mansoni. The crystal structure of annexin B22 confirms the presence of the previously predicted α-helical segment in the II/III linker and reveals a covalently linked head-to-head dimer. From the calcium-bound crystal structure of this protein, canonical type II, type III and B site positions are occupied, and a novel binding site has been identified. The dimer arrangement observed in the crystal structure suggests the presence of two prominent features, a potential non-canonical membrane binding site and a potential binding groove opposite to the former. Results from transcriptional profiling during development show that annexin B22 expression is correlated with life stages of the parasite that possess the syncytial tegument layer, and ultrastructural localization by immuno-electron microscopy confirms the occurrence of annexins in the tegument of S. mansoni. Data from membrane binding and aggregation assays indicate the presence of differential molecular mechanisms and support the hypothesis of annexin B22 providing structural integrity in the tegument.
Genomics of reproduction in parasitic nematodes—fundamental and biotechnological implications
Publisher: Elsevier BV
Date: 04-2003
DOI: 10.1016/S0734-9750(02)00095-2
Abstract: Understanding reproductive and developmental processes of socioeconomically important parasitic nematodes is of fundamental scientific interest and could have important implications for developing novel methods for parasite control via the disruption or interruption of such processes. Central to investigating reproductive molecular biology is the identification and characterisation of genes with sex-specific expression profiles. However, there is currently a paucity of information on such genes and their expression patterns in parasitic nematodes. This article describes recent progress on the characterisation of sex-specific genes from a parasitic nematode of veterinary importance, and discusses the fundamental scientific and applied implications of this work.
Diagnostic and analytical mutation scanning ofCryptosporidium: utility and advantages
Publisher: Informa UK Limited
Date: 03-2009
Abstract: Cryptosporidiosis is predominantly a disease of the alimentary tract of humans and other vertebrates, caused by parasitic protists of the genus Cryptosporidium. This disease, transmitted mainly via the fecal-oral route (in water or food), is of major socioeconomic importance globally. The diagnosis of cryptosporidiosis, including the genetic characterization of the different species, genotypes and subgenotypes (population variants) of Cryptosporidium, is crucial to prevention and control, particularly as there is no cost-effective treatment against this disease. Although traditional phenetic techniques have had major deficiencies for the specific diagnosis of cryptosporidiosis, there has been substantial progress in the establishment of molecular tools. In this article, we review key genetic markers used for the specific identification of Cryptosporidium, diagnosis of cryptosporidiosis and analysis of genetic variation in Cryptosporidium populations. We also discuss the advantages and disadvantages of selected techniques, and emphasize the benefits of utilizing rapid mutation scanning in achieving improved insights into the population genetics and epidemiology of Cryptosporidium.
Haem Biology in Metazoan Parasites – ‘The Bright Side of Haem’
Publisher: Elsevier BV
Date: 03-2019
Abstract: Traditionally, host haem has been recognized as a cytotoxic molecule that parasites need to eliminate or detoxify in order to survive. However, recent evidence indicates that some lineages of parasites have lost genes that encode enzymes involved specifically in endogenous haem biosynthesis. Such lineages thus need to acquire and utilize haem originating from their host animal, making it an indispensable molecule for their survival and reproduction. In multicellular parasites, host haem needs to be systemically distributed throughout their bodies to meet the haem demands in all cell and tissue types. Host haem also gets deposited in parasite eggs, enabling embryogenesis and reproduction. Clearly, a better understanding of haem biology in multicellular parasites should elucidate organismal adaptations to obligatory blood-feeding.
Metabolic profiling and in vitro assessment of anthelmintic fractions of Picria fel-terrae Lour.
Publisher: Elsevier BV
Date: 12-2016
Screening of the ‘Stasis Box’ identifies two kinase inhibitors under pharmaceutical development with activity against Haemonchus contortus
Publisher: Springer Science and Business Media LLC
Date: 05-07-2017
Long lasting insecticidal net use and its associated factors in Limmu Seka District, South West Ethiopia
Publisher: Springer Science and Business Media LLC
Date: 10-01-2018
Assessing the relationship between Malassezia and leishmaniasis in dogs with or without skin lesions
Publisher: Elsevier BV
Date: 2008
New operational taxonomic units of Enterocytozoon in three marsupial species.
Publisher: Springer Science and Business Media LLC
Date: 28-06-2018
Direct comparison of selected methods for genetic categorisation of Cryptosporidium parvum and Cryptosporidium hominis species
Publisher: Elsevier BV
Date: 04-2005
DOI: 10.1016/J.IJPARA.2005.01.001
Abstract: A study was undertaken to compare the performance of five different molecular methods (available in four different laboratories) for the identification of Cryptosporidium parvum and Cryptosporidium hominis and the detection of genetic variation within each of these species. The same panel of oocyst DNA s les derived from faeces (n=54 coded blindly) was sent for analysis by: (i) DNA sequence analysis of a fragment of the HSP70 gene (ii) DNA sequence analysis and the ssrRNA gene in laboratory 1 (iii) single-strand conformation polymorphism analysis of part of the ssrRNA (iv) SSCP analysis of the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA region in laboratory 2 (v) 60 kDa glycoprotein (gp60) gene sequencing with prior species determination using PCR with restriction fragment length polymorphism analysis of the ssrRNA gene in laboratory 3 and (vi) multilocus genotyping at three microsatellite markers in laboratory 4. For detecting variation within C. parvum and C. hominis, SSCP analysis of ITS-2 was considered to have superior utility and determined 'subgenotypes' in s les containing DNA from both species. SSCP was also most cost effective in terms of time, cost and consumables. Sequence analysis of gp60 and microsatellite markers ML1, ML2 and 'gp15' provided good comparators for the SSCP of ITS-2. However, applicability of these methods to other Cryptosporidium species or genotypes and to environmental s les needs to be evaluated. This trial provided, for the first time, a direct comparison of multiple methods for the genetic characterisation of C. parvum and C. hominis s les. A protocol has been established for the international distribution of s les for the characterisation of Cryptosporidium. This can be applied in further evaluation of molecular methods by investigation of a larger number of unrelated s les to establish sensitivity, typability, reproducibility and discriminatory power based on internationally accepted methods for evaluation of microbial typing schemes.
A High-Throughput Phenotypic Screen of the ‘Pandemic Response Box’ Identifies a Quinoline Derivative with Significant Anthelmintic Activity
Publisher: MDPI AG
Date: 21-02-2022
DOI: 10.3390/PH15020257
Abstract: Parasitic nematodes cause diseases in livestock animals and major economic losses to the agricultural industry worldwide. Nematodes of the order Strongylida, including Haemonchus contortus, are particularly important. The excessive use of anthelmintic compounds to treat infections and disease has led to widespread resistance to these compounds in nematodes, such that there is a need for new anthelmintics with distinctive mechanisms of action. With a focus on discovering new anthelmintic entities, we screened 400 chemically erse compounds within the ‘Pandemic Response Box’ (from Medicines for Malaria Venture, MMV) for activity against H. contortus and its free-living relative, Caenorhabditis elegans—a model organism. Using established phenotypic assays, test compounds were evaluated in vitro for their ability to inhibit the motility and/or development of H. contortus and C. elegans. Dose-response evaluations identified a compound, MMV1581032, that significantly the motility of H. contortus larvae (IC50 = 3.4 ± 1.1 μM) and young adults of C. elegans (IC50 = 7.1 ± 4.6 μM), and the development of H. contortus larvae (IC50 = 2.2 ± 0.7 μM). The favourable characteristics of MMV1581032, such as suitable physicochemical properties and an efficient, cost-effective pathway to analogue synthesis, indicates a promising candidate for further evaluation as a nematocide. Future work will focus on a structure-activity relationship investigation of this chemical scaffold, a toxicity assessment of potent analogues and a mechanism/mode of action investigation.
Transcriptomic Resources for Parasitic Nematodes of Veterinary Importance
Publisher: Elsevier BV
Date: 2019
Abstract: Parasitic nematodes are important pathogens of animals, causing diseases that impact on agricultural production worldwide. Research on these worms has been constrained by a lack of genetic and genomic tools. Nonetheless, over the past decade this field has made substantial advances, many of which have been led by transcriptomic sequencing. The present review summarises major transcriptomic studies of veterinary parasitic nematodes in recent years, and comments on overarching themes stemming from this work that inform our understanding of parasitism. Finally, we comment on current, state-of-the-art informatic tools for the analysis of complex worm transcriptomes to extract maximum the molecular information from them.
Molecular characterization of a Toxocara variant from cats in Kuala Lumpur, Malaysia
Publisher: Cambridge University Press (CUP)
Date: 08-1998
DOI: 10.1017/S0031182098002856
Abstract: The ascaridoid nematode of cats from Kuala Lumpur, Malaysia, previously identified morphologically as Toxocara canis , was characterized using a molecular approach. The nuclear ribosomal DNA (rDNA) region spanning the first internal transcribed spacer (ITS-1), the 5·8S gene and the second internal transcribed spacer (ITS-2) was lified and sequenced. The sequences for the parasite from Malaysian cats were compared with those for T. canis and T. cati . The sequence data showed that this taxon was genetically more similar to T. cati than to T. canis in the ITS-1, 5·8S and ITS-2. Differences in the ITS-1 and ITS-2 sequences between the taxa (9·4–26·1%) were markedly higher than variation between s les within T. canis and T. cati (0–2·9%). The sequence data demonstrate that the parasite from Malaysian cats is neither T. canis nor T. cati and indicate that it is a distinct species. Based on these data, PCR-linked restriction fragment length polymorphism (RFLP) and single-strand conformation polymorphism (SSCP) methods were employed for the unequivocal differentiation of the Toxocara variant from T. canis and T. cati . These methods should provide valuable tools for studying the life-cycle, transmission pattern(s) and zoonotic potential of this parasite.
Advances in developing molecular-diagnostic tools for strongyloid nematodes of equids: fundamental and applied implications.
Publisher: Elsevier BV
Date: 02-2004
Experimental infections of pigs and mice with selected genotypes of Ascaris
Publisher: Cambridge University Press (CUP)
Date: 11-07-2006
An improved molecular diagnostic assay for canine and feline dermatophytosis
Publisher: Oxford University Press (OUP)
Date: 02-2013
DOI: 10.3109/13693786.2012.691995
Abstract: The few studies attempting to specifically characterize dermatophytes from hair s les of dogs and cats using PCR-based methodology relied on sequence-based analysis of selected genetic markers. The aim of the present investigation was to establish and evaluate a PCR-based approach employing genetic markers of nuclear DNA for the specific detection of dermatophytes on such specimens. Using 183 hair s les, we directly compared the test results of our one-step and nested-PCR assays with those based on conventional microscopy and in vitro culture techniques (using the latter as the reference method). The one step-PCR was highly accurate (AUC > 90) for the testing of s les from dogs, but only moderately accurate (AUC = 78.6) for cats. A nested-PCR was accurate (AUC = 93.6) for s les from cats, and achieved higher specificity (94.1 and 94.4%) and sensitivity (100 and 94.9%) for s les from dogs and cats, respectively. In addition, the nested-PCR allowed the differentiation of Microsporum canis from Trichophyton interdigitale (zoophilic) and geophilic dermatophytes (i.e., Microsporum gypseum or Trichophyton terrestre), which was not possible using the one step-assay. The PCRs evaluated here provide practical tools for diagnostic applications to support clinicians in initiating prompt and targeted chemotherapy of dermatophytoses.
Necator americanus (Nematoda: Ancylostomatidae) from Africa and Malaysia have different ITS-2 rDNA sequences
Publisher: Elsevier BV
Date: 04-1998
DOI: 10.1016/S0020-7519(97)00213-0
Abstract: The nucleotide sequences of the second internal transcribed spacer of rDNA were determined for adult worms of Necator americanus originating from Togo (Africa) and Sarawak (Malaysia). The length of the sequences of specimens from Togo (325 bp) were shorter than those from Sarawak (327 bp). There were six fixed genetic differences in the aligned sequences of N. americanus from Sarawak and Togo, excluding one or two polymorphic sites within the sequence of N. americanus from each geographical region. These findings suggest that there is either population variation in the sequence of N. americanus, or that N. americanus from the two countries may represent genetically distinct but morphologically similar (i.e. cryptic) species, however, comparison of the sequence differences among other hookworm species supports the latter conclusion.
Distinguishing Oesophagostomum dentatum from Oesophagostomum quadrispinulatum developmental stages by a single-strand conformation polymorphism method
Publisher: Elsevier BV
Date: 12-1998
DOI: 10.1016/S0020-7519(98)00133-7
Abstract: At some life-cycle stages, it is impossible to distinguish between the two species of porcine nodular worm, Oesophagostomum dentatum and Oesophagostomum quadrispinulatum, using morphological features. A PCR-based single-strand conformation polymorphism technique was established to overcome this limitation. The rDNA region spanning the second internal transcribed spacer was lified by PCR from genomic DNA from morphologically well-defined adult worms. The PCR products were then denatured and subjected to electrophoresis in a non-denaturing gel matrix. Single-strand conformation polymorphism analysis of the products generated characteristic and reproducible patterns for each of the two species and allowed their unequivocal delineation. The single-strand conformation polymorphism was also applied effectively to assess the purity of nine laboratory-maintained cultures of infective third-stage larvae believed to be monospecific for O. dentatum or O. quadrispinulatum. The analysis showed that all six O. dentatum cultures were indeed monospecific, whereas the three cultures believed to be monospecific for O. quadrispinulatum were either a mixture of O. dentatum and O. quadrispinulatum larvae or pure O. dentatum larvae. These findings demonstrated the usefulness of the single-strand conformation polymorphism approach for the routine monitoring of the purity of parasite "lines" and indicated its value for studies on the population biology of porcine nodular worms.
Special issue – Learning and teaching of veterinary parasitology
Publisher: Elsevier BV
Date: 04-2018
Ancipirhynchus afossalis n. g., n. sp. (Trypanorhyncha: Otobothriidae), from two species of sharks off Indonesian and Malaysian Borneo.
Publisher: Springer Science and Business Media LLC
Date: 31-07-2011
DOI: 10.1007/S11230-011-9309-8
Abstract: A new genus of trypanorhynch cestode is described from two species of sharks, the sliteye shark Loxodon macrorhinus Müller & Henle and the straight-tooth weasel shark Paragaleus tengi (Chen) collected in the Makassar Strait (off Indonesian Borneo) and Sulu Sea (off Malaysian Borneo). Ancipirhynchus afossalis n. g., n. sp. possesses two bothria and a heteroacanthous, heteromorphous tentacular armature with three distinctive files of hooks on the external tentacle surface but lacks prebulbar organs and gland cells within the tentacular bulbs. The hook arrangement of alternating files on the external surface of the tentacle resembles that seen in the superfamily Otobothrioidea Dollfus, 1942 in the genus Fossobothrium Beveridge & C bell, 2005. However, the new species lacks the defining characteristic of this group, i.e. the paired bothrial pits. A Bayesian inference (BI) analysis of 37 LSU sequences of trypanorhynchs from three superfamilies provided evidence supporting the taxonomic placement of Ancipirhynchus afossalis n. g., n. sp. within the Otobothrioidea.
Determination of the optimum cut-off value of a diagnostic test
Publisher: Elsevier BV
Date: 12-1990
Working towards New Drugs against Parasitic Worms in a Public-Development Partnership
Publisher: Elsevier BV
Date: 2018
Abstract: There is a clear need to develop new and inexpensive drugs to alleviate diseases caused by parasitic worms in animals and humans worldwide. In this article we discuss the roles and advantages of working in public-private partnerships (PPPs) - among academia, industry, and philanthropy - to enable anthelmintic drug discovery.
Isolation and characterisation of sex-specific transcripts from Oesophagostomum dentatum by RNA arbitrarily-primed PCR
Publisher: Elsevier BV
Date: 05-2000
DOI: 10.1016/S0166-6851(00)00217-6
Abstract: In light of the lack of molecular data on the sexual differentiation, maturation and interaction of parasitic nematodes of livestock, the present study investigated sex-specific gene expression in the nodule worm, Oesophagostomum dentatum (Strongylida). Using the technique of RNA arbitrarily-primed polymerase chain reaction (RAP-PCR), 31 expressed sequence tags (ESTs) differentially-displayed between the sexes were cloned. Northern blot analysis proved ten ESTs to be expressed exclusively in males (adults and fourth-stage larvae), while two were expressed solely in female stages. None of the ESTs were expressed in infective third-stage larvae. Sequence analysis and subsequent database searches revealed two male-specific ESTs to have significant similarity to Caenorhabditis elegans (predicted) proteins, a protein containing an EGF-like cysteine motif and a serine/threonine phosphatase. Another two male-specific ESTs had similarity to non-nematode sequences. The two female-specific ESTs had similarity to vitellogenin-5 and endonuclease III (predicted) from C. elegans. The remaining ESTs had no similarity to any nucleic acid or protein sequences contained in the databases. The isolation and characterisation of sex-specific ESTs from O. dentatum provides a unique opportunity for studying the reproductive biology of parasitic nematodes at the molecular level, with a view toward novel approaches for parasite control.
Systematic relationships of some members of the genera Oesophagostomum and Chabertia (Nematoda: Chabertiidae) based on ribosomal dna sequence data
Publisher: Elsevier BV
Date: 11-1998
DOI: 10.1016/S0020-7519(98)00144-1
Abstract: The present study characterised seven species of the Chabertiidae (Nematoda: Strongyloidea) belonging to either the subfamily Oesophagostominae (Oesophagostomum radiatum, Oesophagostomum venulosum, Oesophagostomum dentatum, Oesophagostomum quadrispinulatum, Oesophagostomum columbianum, Oesophagostomum bifurcum) or to the subfamily Chabertiinae (Chabertia ovina) by their second internal transcribed spacer rDNA sequence, assessed the extent of intraspecific variation and interspecific differences in the sequence, and inferred the phylogenetic relationship of C. ovina with respect to members of the Oesophagostominae. In both the phenetic and cladistic analyses of the sequence data, Chabertia was nested within Oesophagostomum, suggesting either that the species examined represent members of the same genus, or alternatively, that Oesophagostomum may represent more than one genus.
The distribution of Anoplocephala perfoliata in the intestine of the horse and associated pathological changes
Publisher: Elsevier BV
Date: 12-1997
DOI: 10.1016/S0304-4017(97)00123-4
Abstract: The intestinal tracts of 130 horses were examined for infection with Anoplocephala perfoliata at necropsy. Fifty horses (38.5%) harboured the tapeworm, and the site of attachment of each worm was recorded using predetermined anatomical landmarks. The worms were attached in four regions of the gastrointestinal tract: 17% of the worms were found at the ileocaecal junction, 81% on the caecal wall, 1.7% in the terminal ileum and 0.2% in the ventral colon. The severity of lesions produced at the sites of attachment was related to the number of worms attached. Due to the small area of the ileocaecal junction, worms at this site were attached in close proximity, resulting in more severe lesions. The major features of the lesions included ulceration, diphtheritic membranes and thickening of the mucosa, submucosa and lamina propria. There was an increase in the number of eosinophils and a decrease in the number of lymphocytes present at the sites of lesions.
Monoaminergic signaling as a target for anthelmintic drug discovery: Receptor conservation among the free-living and parasitic nematodes
Publisher: Elsevier BV
Date: 05-2012
High Resolution Genotyping of Cryptosporidium by Mutation Scanning
Publisher: Elsevier
Date: 2003
Needles in the EST haystack: Large-scale identification and analysis of excretory-secretory (ES) proteins in parasitic nematodes using expressed sequence tags (ESTs)
Publisher: Public Library of Science (PLoS)
Date: 24-09-2008
A male-specific (cysteine-rich) protein of Oesophagostomum dentatum (Strongylida) with structural characteristics of a serine protease inhibitor containing two trypsin inhibitor-like domains
Publisher: Cambridge University Press (CUP)
Date: 05-2002
DOI: 10.1017/S0031182002002329
Abstract: A cDNA was isolated from an adult male Oesophagostomum dentatum gene library by screening with a male-specific, partial expressed sequence tag (EST) probe identified previously using a differential display technique. The full-length cDNA of 642 bp included 5′ and 3′ untranslated regions of 44 and 121 nucleotides, respectively, and encoded a predicted protein with a putative 18 amino acid signal sequence and a mature polypeptide of 14.7 kDa comprising ∼15% cysteine residues. The amino acid sequence showed similarity with a number of proteins from Caenorhabditis elegans , parasitic nematodes, insects and hibia, all of which contain a trypsin inhibitor-like cysteine-rich domain. A 3-dimensional structure model constructed for the O. dentatum protein (designated OdmCRP) inferred that it is composed of 2 domains, each with 5 disulfide bonds, which are indicative of the Ascaris family of serine protease inhibitors. These findings indicate that OdmCRP, with 2 structural domains relating to functionally active sites, is a new member of this inhibitor family.
Case-Control Study to Assess the Association between Epilepsy and Toxocara Infection/Exposure
Publisher: MDPI AG
Date: 03-10-2021
DOI: 10.3390/MICROORGANISMS9102091
Abstract: Although causes and etiology of epilepsy are mostly obscure, some zoonotic parasites, such as Toxocara species, have been proposed as a risk factor for this disease. Here, we conducted an age-matched case-control study to evaluate whether there is an association between epilepsy and the presence of serum antibodies to Toxocara in incident cases. We included 94 idiopathic epileptic patients as cases, and—from the same geographical region—88 people with no own history of epilepsy or neurological disease as control subjects. Epilepsy was confirmed by a physician using the International League Against Epilepsy (ILAE) definition. All participants were screened for the anti-Toxocara IgG serum antibody by enzyme-linked immunosorbent assay (ELISA). Univariate and mutltivariate statistical analyses were applied to calculate the crude and adjusted odds ratios (OR) and 95% confidence intervals (CIs). Anti-Toxocara serum antibody was detected in 37 epileptic patients and in 23 control subjects, giving respective seroprevalences of 39.3% (95% CI, 29.4–49.9%) and 26.1% (95% CI, 17.3–36.5%), respectively. Adjusted multivariate logistic regression analysis estimated an OR of 2.38 (95% CI, 1.25–4.63), indicating a significant association between epilepsy and Toxocara seropositivity. There was also a significant association between seropositivity to Toxocara and partial (OR, 2.60 95% CI, 1.14–6.04) or generalized (OR, 2.17 95% CI, 1.09–4.40%) seizures. Findings from the present study of incident epileptic cases support previous studies proposing that Toxocara infection/exposure is a risk factor for epilepsy. However, further well-designed population-based surveys and mechanistic/experimental studies in animal models are required to better understand the reason(s) for this association.
Genetic evidence indicating that Cooperia surnabada and Cooperia oncophora are one species
Publisher: Elsevier BV
Date: 02-1998
DOI: 10.1016/S0020-7519(97)00149-5
Abstract: Sequences of the second internal transcribed spacer (ITS-2) of ribosomal DNA were determined for the trichostrongylid nematodes Cooperia surnabada and Cooperia oncophora, to test the hypothesis that they represent one species. Also included for comparison were other morphologically distinct species within the genus, namely Cooperia punctata and Cooperia curticei. There were no differences in the consensus ITS-2 sequences between C. oncophora and C. surnabada, whereas each taxon differed from C. punctata and C. curticei by 1.7% and 4.1%, respectively. Also, C. punctata differed from C. curticei by 5.0%. Based on these results and the DNA studies of other trichostrongylid species, it is proposed that C. oncophora and C. surnabada represent a single species.
What’s in that band?
Publisher: Elsevier BV
Date: 06-1998
DOI: 10.1016/S0020-7519(98)00046-0
Abstract: The analysis of molecular variation in parasites has important implications for studying gene function and organisation, taxonomy, phylogeny and population genetics. Polymerase chain reaction-based mutation scanning methods can have significant advantages over some currently used DNA approaches for the analysis of allelic and mutational sequence variation in parasites. The present report describes briefly the principles of some of these methods, examines some of their advantages and disadvantages, and indicates their potential for applications in parasitology.
Cryptosporidium cf. avium in an inland-bearded dragon (Pogona vitticeps) – A case report and review of the literature
Publisher: Elsevier BV
Date: 12-2020
The RIO protein kinase-encoding gene Sj-riok-2 is involved in key reproductive processes in Schistosoma japonicum
Publisher: Springer Science and Business Media LLC
Date: 12-2017
Genetic analysis of Giardia and Cryptosporidium from people in Northern Australia using PCR-based tools
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.MEEGID.2015.08.034
Abstract: To date, there has been limited genetic study of the gastrointestinal pathogens Giardia and Cryptosporidium in northern parts of Australia. Here, PCR-based methods were used for the genetic characterization of Giardia and Cryptosporidium from 695 people with histories of gastrointestinal disorders from the tropical North of Australia. Genomic DNAs from fecal s les were subjected to PCR-based analyses of regions from the triose phosphate isomerase (tpi), small subunit (SSU) of the nuclear ribosomal RNA and/or the glycoprotein (gp60) genes. Giardia and Cryptosporidium were detected in 13 and four of the 695 s les, respectively. Giardia duodenalis assemblages A and B were found in 4 (31%) and 9 (69%) of the 13 s les in persons of <9 years of age. Cryptosporidium hominis (subgenotype IdA18), Cryptosporidium mink genotype (subgenotype IIA16R1) and C. felis were also identified in single patients of 11-21 years of age. Future studies might focus on a comparative study of these and other protists in rural communities in Northern Australia.
Differences in the 5.8S rDNA sequences among ascarid nematodes
Publisher: Elsevier BV
Date: 04-1998
DOI: 10.1016/S0020-7519(97)00214-2
Abstract: Sequences of the 5.8S rDNA were obtained for 14 species of nematode from different superfamilies and families within the order Ascaridida. All sequences were 157 bp in length. Sequence differences among species ranged from 0 to 18 bp (0-11.5%). A phenetic analysis of the sequence data groups the 14 taxa into their respective superfamilies and families, but does not discriminate fully at the subfamily level. A phylogenetic analysis of the sequence data failed to resolve the evolutionary relationships at the superfamily level. The 5.8S gene may be useful for phylogenetic studies of the phylum Nematoda at the ordinal level.
Genetic variability within and among Haemonchus contortus isolates from goats and sheep in China
Publisher: Springer Science and Business Media LLC
Date: 25-09-2013
Abstract: Haemonchus contortus (order Strongylida) is a common parasitic nematode infecting small ruminants and causing significant economic losses worldwide. Knowledge of genetic variation within and among H. contortus populations can provide a foundation for understanding transmission patterns, the spread of drug resistance alleles and might assist in the control of haemonchosis. 152 H. contortus in idual adult worms were collected from seven different geographical regions in China. The second internal transcribed spacer (ITS-2) of the nuclear ribosomal DNA and mitochondrial nicotinamide dehydrogenase subunit 4 gene ( nad 4) were lified by polymerase chain reaction (PCR) and sequenced directly. The sequence variations and population genetic ersities were determined. Nucleotide sequence analyses revealed 18 genotypes (ITS-2) and 142 haplotypes ( nad 4) among the 152 worms, with nucleotide ersities of 2.6% and 0.027, respectively, consistent with previous reports from other countries, including Australia, Brazil, Germany, Italy, Malaysia, Sweden, the USA and Yemen. Population genetic analyses revealed that 92.4% of nucleotide variation was partitioned within populations there was no genetic differentiation but a high gene flow among Chinese populations some degree of genetic differentiation was inferred between some specimens from China and those from other countries. This is the first study of genetic variation within H. contortus in China. The results revealed high within-population variations, low genetic differentiation and high gene flow among different populations of H. contortus in China. The present results could have implications for studying the epidemiology and ecology of H. contortus in China.
Cryptosporidium parvum genotype IIa and Giardia duodenalis assemblage A in Mytilus galloprovincialis on sale at local food markets
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.IJFOODMICRO.2013.11.022
Abstract: To date, there has been no study to establish the genotypic or subgenotypic identities of Cryptosporidium and Giardia in edible shellfish. Here, we explored the genetic composition of these protists in Mytilus galloprovincialis (Mediterranean mussel) purchased from three markets in the city of Foggia, Italy, from May to December 2012. S les from the digestive glands, gills and haemolymph were tested by nested PCR, targeting DNA regions within the 60 kDa glycoprotein (gp60) gene of Cryptosporidium, and the triose-phosphate isomerase (tpi) and β-giardin genes of Giardia. In total, Cryptosporidium and Giardia were detected in 66.7% of mussels (M. galloprovincialis) tested. Cryptosporidium was detected mostly between May and September 2012. Sequencing of licons showed that 60% of mussels contained Cryptosporidium parvum genotype IIa (including subgenotypes A15G2R1, IIaA15G2 and IIaA14G3R1), 23.3% Giardia duodenalis assemblage A, and 6.6% had both genetic types. This is the first report of these types in fresh, edible shellfish, particularly the very commonly consumed M. galloprovincialis from highly frequented fish markets. These genetic types of Cryptosporidium and Giardia are known to infect humans and thus likely to represent a significant public health risk. The poor observance of hygiene rules by vendors, coupled to the large numbers of M. galloprovincialis sold and the eating habits of consumers in Italy, call for more effective sanitary measures pertaining to the selling of fresh shellfish in street markets.
Bioinformatics meets parasitology
Publisher: Wiley
Date: 09-04-2012
DOI: 10.1111/J.1365-3024.2011.01304.X
Abstract: The advent and integration of high-throughput '-omics' technologies (e.g. genomics, transcriptomics, proteomics, metabolomics, glycomics and lipidomics) are revolutionizing the way biology is done, allowing the systems biology of organisms to be explored. These technologies are now providing unique opportunities for global, molecular investigations of parasites. For ex le, studies of a transcriptome (all transcripts in an organism, tissue or cell) have become instrumental in providing insights into aspects of gene expression, regulation and function in a parasite, which is a major step to understanding its biology. The purpose of this article was to review recent applications of next-generation sequencing technologies and bioinformatic tools to large-scale investigations of the transcriptomes of parasitic nematodes of socio-economic significance (particularly key species of the order Strongylida) and to indicate the prospects and implications of these explorations for developing novel methods of parasite intervention.
Assessing calves as carriers of Cryptosporidium and Giardia with zoonotic potential on dairy and beef farms within a water catchment area by mutation scanning.
Publisher: Wiley
Date: 08-2013
Abstract: In the present study, we undertook a molecular epidemiological survey of Cryptosporidium and Giardia in calves on three dairy and two beef farms within an open drinking water catchment area (Melbourne, Australia). Faecal s les (n = 474) were collected from calves at two time points (5 months apart) and tested using a PCR-based mutation scanning-targeted sequencing phylogenetic approach, employing regions within the genes of small subunit (SSU) of ribosomal RNA (designated partial SSU), 60 kDa glycoprotein (pgp60) and triose phosphate isomerase (ptpi) as genetic markers. Using partial SSU, the C. bovis, C. parvum, C. ryanae and a new genotype of Cryptosporidium were characterised from totals of 74 (15.6%), 35 (7.3%), 37 (7.8%) and 9 (1.9%) s les, respectively. Using pgp60, C. parvum genotype IIa subgenotype A18G3R1 was detected in 29 s les. Using ptpi, G. duodenalis assemblages A and E were detected in totals of 10 (2.1%) and 130 (27.4%) s les, respectively. The present study showed that a considerable proportion of dairy and beef calves in this open water catchment region excreted Cryptosporidium (i.e. subgenotype IIaA18G3R1) and Giardia (e.g. assemblage A) that are consistent with those infecting humans, inferring that they are of zoonotic importance. Future work should focus on exploring, in a temporal and spatial way, whether these parasites occur in the environment and water of the catchment reservoir.
Elucidating ANTs in worms using genomic and bioinformatic tools - Biotechnological prospects?
Publisher: Elsevier BV
Date: 2010
DOI: 10.1016/J.BIOTECHADV.2009.09.001
Abstract: Adenine nucleotide translocators (ANTs) belong to the mitochondrial carrier family (MCF) of proteins. ATP production and consumption are tightly linked to ANTs, the kinetics of which have been proposed to play a key regulatory role in mitochondrial oxidative phosphorylation. ANTs are also recognized as a central component of the mitochondrial permeability transition pore associated with apoptosis. Although ANTs have been investigated in a range of vertebrates, including human, mouse and cattle, and invertebrates, such as Drosophila melanogaster (vinegar fly), Saccharomyces cerevisiae (yeast) and Caenorhabditis elegans (free-living nematode), there has been a void of information on these molecules for parasitic nematodes of socio-economic importance. Exploring ANTs in nematodes has the potential lead to a better understanding of their fundamental roles in key biological pathways and might provide an avenue for the identification of targets for the rational design of nematocidal drugs. In the present article, we describe the discovery of an ANT from Haemonchus contortus (one of the most economically important parasitic nematodes of sheep and goats), conduct a comparative analysis of key ANTs and their genes (particularly ant-1.1) in nematodes and other organisms, predict the functional roles utilizing a combined genomic-bioinformatic approach and propose ANTs and associated molecules as possible drug targets, with the potential for biotechnological outcomes.
Molecular detection of Cyclospora in water, soil, vegetables and humans in southern Italy signals a need for improved monitoring by health authorities
Publisher: Elsevier BV
Date: 10-2015
DOI: 10.1016/J.IJFOODMICRO.2015.07.002
Abstract: To date, in Europe, there is scant information on the occurrence of Cyclospora in water from treatment plants and in humans, and no data are available on soil or fresh plant products. Here, we undertook the first molecular survey of Cyclospora in multiple biological matrices collected from the Apulia region of southern Italy. S les of irrigation water from four municipal treatment plants, eight different types of vegetables or fruit (cucumber, lettuce, fennel, celery, tomato, melon, en e and chicory) and soil from the same farms on which these plants were grown, as well as faecal s les from humans living in the same region were tested by qPCR-coupled single-strand conformation polymorphism (SSCP) analysis and DNA sequencing. Cyclospora was detected in 15.5% of all 213 s les tested. Specifically, this protist was detected in (i) treated water (21.3% of 94 s les), well water (6.2% of 16), but not drinking water (0% of 3) (ii) soil (11.8% of 51 s les) and vegetables (12.2% of 49), with the highest prevalence (18.7%) on fennel and (iii) human stools (27.5% of 40 s les). In environmental and food s les, Cyclospora was detected mainly in autumn and was significantly more prevalent in the faeces from humans of 40-50 years of age. This is the first comprehensive molecular survey of Cyclospora in environmental, food and human faecal s les in Europe. These data suggest that irrigation water, soil and vegetables might be contaminated by Cyclospora cayetanensis, which might represent a source of infection to humans in the study area and calls for monitoring by health authorities.
The redlegged earth mite draft genome provides new insights into pesticide resistance evolution and demography in its invasive Australian range
Publisher: Cold Spring Harbor Laboratory
Date: 04-08-2022
DOI: 10.1101/2022.08.03.502713
Abstract: Genomic data provide valuable insights into pest management issues such as resistance evolution, historical patterns of pest invasions and ongoing population dynamics. We assembled the first reference genome for the redlegged earth mite, Halotydeus destructor (Tucker, 1925), to investigate adaptation to pesticide pressures and demography in its invasive Australian range using whole-genome pool-seq data from regionally distributed populations. Our reference genome comprises 132 autosomal contigs, with a total length of 48.90 Mb. We observed a large complex of ace genes, which has presumably evolved from a long history of organophosphate selection in H. destructor and may contribute toward organophosphate resistance through copy number variation, target-site mutations, and structural variants. In the putative ancestral H. destructor ace gene, we identified three target-site mutations (G119S, A201S, and F331Y) segregating in organophosphate resistant populations. Additionally, we identified two new para sodium channel gene mutations (L925I and F1020Y) that may contribute to pyrethroid resistance. Regional structuring observed in population genomic analyses indicates that gene flow in H. destructor does not homogenise populations across large geographic distances. However, our demographic analyses were equivocal on the magnitude of gene flow the short invasion history of H. destructor makes it difficult to distinguish scenarios of complete isolation vs. ongoing migration. Nonetheless, we identified clear signatures of reduced genetic ersity and smaller inferred effective population sizes in eastern vs. western populations, which is consistent with the stepping-stone invasion pathway of this pest in Australia. These new insights will inform development of diagnostic genetic markers of resistance, further investigation into the multifaceted organophosphate resistance mechanism, and predictive modelling of resistance evolution and spread.
Nuclear genome of Bulinus truncatus, an intermediate host of the carcinogenic human blood fluke Schistosoma haematobium
Publisher: Springer Science and Business Media LLC
Date: 21-02-2022
DOI: 10.1038/S41467-022-28634-9
Abstract: Some snails act as intermediate hosts (vectors) for parasitic flatworms (flukes) that cause neglected tropical diseases, such as schistosomiases. Schistosoma haematobium is a blood fluke that causes urogenital schistosomiasis and induces bladder cancer and increased risk of HIV infection. Understanding the molecular biology of the snail and its relationship with the parasite could guide development of an intervention approach that interrupts transmission. Here, we define the genome for a key intermediate host of S. haematobium —called Bulinus truncatus —and explore protein groups inferred to play an integral role in the snail’s biology and its relationship with the schistosome parasite. Bu. truncatus shared many orthologous protein groups with Biomphalaria glabrata —the key snail vector for S. mansoni which causes hepatointestinal schistosomiasis in people. Conspicuous were expansions in signalling and membrane trafficking proteins, peptidases and their inhibitors as well as gene families linked to immune response regulation, such as a large repertoire of lectin-like molecules. This work provides a sound basis for further studies of snail-parasite interactions in the search for targets to block schistosomiasis transmission.
PCR assay for the specific amplification of Oesophagostomum bifurcum DNA from human faeces
Publisher: Elsevier BV
Date: 02-2000
DOI: 10.1016/S0020-7519(99)00175-7
Abstract: Oesophagostomiasis in humans due to infection with Oesophagostomum bifurcum (nodule worm) is of major human health significance in northern Togo and Ghana where the human hookworm, Necator americanus, also exists at high prevalence. Accurate diagnosis of O. bifurcum infection in humans is central to studying the epidemiology and controlling the parasite. To overcome limitations of current copro-diagnostic methods, we have developed an alternative, molecular approach. Utilising genetic markers in the second internal transcribed spacer (ITS-2) of ribosomal DNA, we have established a two-step, semi-nested PCR method for the specific lification of minute amounts (fg) of O. bifurcum DNA from human faecal s les. Using a panel of 155 well-defined faecal and DNA s les, the assay achieved a sensitivity of 94.6% and a specificity of 100%. This PCR assay will be useful for the diagnosis of O. bifurcum infection and as a molecular tool for elucidating the epidemiology of human oesophagostomiasis.
Using a Bioactive Eremophila-Derived Serrulatane Scaffold to Generate a Unique Carbamate Library for Anti-infective Evaluations
Publisher: American Chemical Society (ACS)
Date: 17-02-2023
Impact of gastrointestinal parasitic nematodes of sheep, and the role of advanced molecular tools for exploring epidemiology and drug resistance - an Australian perspective
Publisher: Springer Science and Business Media LLC
Date: 27-05-2013
Molecular diagnosis of scabies using a novel probe-based polymerase chain reaction assay targeting high-copy number repetitive sequences in the Sarcoptes scabiei genome.
Publisher: Public Library of Science (PLoS)
Date: 24-02-2021
DOI: 10.1371/JOURNAL.PNTD.0009149
Abstract: The suboptimal sensitivity and specificity of available diagnostic methods for scabies h ers clinical management, trials of new therapies and epidemiologic studies. Additionally, parasitologic diagnosis by microscopic examination of skin scrapings requires s le collection with a sharp scalpel blade, causing discomfort to patients and difficulty in children. Polymerase chain reaction (PCR)-based diagnostic assays, combined with non-invasive s ling methods, represent an attractive approach. In this study, we aimed to develop a real-time probe-based PCR test for scabies, test a non-invasive s ling method and evaluate its diagnostic performance in two clinical settings. High copy-number repetitive DNA elements were identified in draft Sarcoptes scabiei genome sequences and used as assay targets for diagnostic PCR. Two suitable repetitive DNA sequences, a 375 base pair microsatellite (SSR5) and a 606 base pair long tandem repeat (SSR6), were identified. Diagnostic sensitivity and specificity were tested using relevant positive and negative control materials and compared to a published assay targeting the mitochondrial cox1 gene. Both assays were positive at a 1:100 dilution of DNA from a single mite no lification was observed in DNA from s les from 19 patients with other skin conditions nor from house dust, sheep or dog mites, head and body lice or from six common skin bacterial and fungal species. Moderate sensitivity of the assays was achieved in a pilot study, detecting 5/7 (71.4% [95% CI: 29.0% - 96.3%]) of clinically diagnosed untreated scabies patients). Greater sensitivity was observed in s les collected by FLOQ swabs compared to skin scrapings. This newly developed qPCR assay, combined with the use of an alternative non-invasive swab s ling technique offers the possibility of enhanced diagnosis of scabies. Further studies will be required to better define the diagnostic performance of these tests.
Nucleotide alterations in the D3 domain of the large subunit of ribosomal DNA among 21 species of equine strongyle.
Publisher: Elsevier BV
Date: 04-2006
DOI: 10.1016/J.MCP.2006.08.008
Abstract: The expansion segments or ergent (D) domains in the large subunit (LSU) of the ribosomal DNA have been suggested as genetic markers for taxonomic and/or phylogenetic studies of parasites. In the present study, we assessed the degree of sequence variation in the D3 domain and flanking core regions of the LSU for 21 species of equine strongyles (Strongylida: Strongylidae) and determined which positions in the secondary structure of the LSU were associated with the nucleotide alterations. No intraspecific sequence variation was detected in 17 species, for which multiple in idual worms were available. Mutations in sequence among species were detected at 19 nucleotide positions, most of which were located in the D3 domain. Fifteen alterations were transitions, three were transversions and one represented a site of multiple mutations. In relation to the secondary structure element of D3, 26% of these mutations were located in unpaired regions (i.e., end of loops, or in bulges of helices) and thus did not appear to alter the pairing arrangement in the helices of the secondary structure. Many of the other mutations represented partial or complete compensatory base pair changes. The magnitude of interspecific nucleotide variation in the D3 domain (0-4%) was considerably less than that recorded for some other nematode groups (enoplids and thelastomatoids), indicating that this region alone is of limited value for taxonomic and phylogenetic studies for strongyles of equids but is interesting in relation to the evolution of ribosomal DNA.
Insights into the immuno-molecular biology of Angiostrongylus vasorum through transcriptomics-Prospects for new interventions
Publisher: Elsevier BV
Date: 12-2013
DOI: 10.1016/J.BIOTECHADV.2013.07.006
Abstract: Angiostrongylus vasorum is a metastrongyloid nematode of dogs and other canids of major clinical importance in many countries. In order to gain first insights into the molecular biology of this worm, we conducted the first large-scale exploration of its transcriptome, and predicted essential molecules linked to metabolic and biological processes as well as host immune responses. We also predicted and prioritized drug targets and drug candidates. Following Illumina sequencing (RNA-seq), 52.3 million sequence reads representing adult A. vasorum were assembled and annotated. The assembly yielded 20,033 contigs, which encoded proteins with 11,505 homologues in Caenorhabditis elegans, and additional 2252 homologues in various other parasitic helminths for which curated data sets were publicly available. Functional annotation was achieved for 11,752 (58.6%) proteins predicted for A. vasorum, including peptidases (4.5%) and peptidase inhibitors (1.6%), protein kinases (1.7%), G protein-coupled receptors (GPCRs) (1.5%) and phosphatases (1.2%). Contigs encoding excretory/secretory and immuno-modulatory proteins represented some of the most highly transcribed molecules, and encoded enzymes that digest haemoglobin were conserved between A. vasorum and other blood-feeding nematodes. Using an essentiality-based approach, drug targets, including neurotransmitter receptors, an important chemosensory ion channel and cysteine proteinase-3 were predicted in A. vasorum, as were associated small molecular inhibitors/activators. Future transcriptomic analyses of all developmental stages of A. vasorum should facilitate deep explorations of the molecular biology of this important parasitic nematode and support the sequencing of its genome. These advances will provide a foundation for exploring immuno-molecular aspects of angiostrongylosis and have the potential to underpin the discovery of new methods of intervention.
Comparative evaluation of two DNA isolation techniques for PCR-based diagnosis of gastrointestinal nematode infections in sheep
Publisher: Elsevier BV
Date: 06-2013
DOI: 10.1016/J.MCP.2013.03.002
Abstract: The specific diagnosis of gastrointestinal parasite infections in livestock is central to their control. PCR assays have been developed for routine diagnosis and to overcome limitations of classical methods. Central to the performance of such assays is the effective isolation of the nucleic acids from s les and the elimination of components that are inhibitory to PCR. Here, we directly compared two techniques for the isolation of DNA from strongylid nematode eggs from faecal s les from sheep, and assessed their performance in relation to the sensitivity and specificity of PCR, time required for DNA isolation and ease of use. The results showed differences in the performance of the two isolation techniques, subsequently effecting the PCR results. The main differences related to the time required for DNA isolation, and the elimination of inhibitory substances from the DNA isolated by one technique but not the other.
Comparative genome analysis indicates high evolutionary potential of pathogenicity genes in Colletotrichum tanaceti
Publisher: Public Library of Science (PLoS)
Date: 31-05-2019
Extensive and complex sequence diversity in mitochondrial cytochrome c oxidase subunit 1 within Necator americanus from Colombia revealed by SSCP-coupled sequencing
Publisher: Elsevier BV
Date: 08-2008
DOI: 10.1016/J.MCP.2008.04.001
Abstract: In spite of the human health importance of hookworms, there has been only a small number of studies of genetic variability within Necator americanus, and none in South America. In the present study, we investigated sequence variability in a 395-bp region of the mitochondrial cytochrome c oxidase subunit 1 gene among N. americanus in iduals (n=100) from humans of six villages in Colombia, employing a mutation scanning-coupled sequencing approach. Haplotypic ersity within N. americanus varied from 0.95 to 1.0 (0.9743+/-0.0068) and nucleotide ersity from 0.025 to 0.045 (0.0257+/-0.013). Nucleotide variation was reflected in nine amino acid alterations over 132 positions. The network of cox1 haplotypes (n=59) displayed a complex relationship with no apparent association between haplotype and geographical origin in Colombia. The extensive haplotypic variability detected suggests different epidemiological or disease characteristics for distinct population variants of N. americanus.
Ascaris egg profiles in human faeces: biological and epidemiological implications
Publisher: Cambridge University Press (CUP)
Date: 09-2003
DOI: 10.1017/S0031182003003615
Abstract: Since 2 morphological forms (fertilized and unfertilized) of egg can be produced by Ascaris , infected humans can release in their faeces fertilized eggs only (FEO), unfertilized eggs only (UEO) or both fertilized and unfertilized eggs (FUE) (designated herein as the 3 different egg profiles). Epidemiologically, fertilized eggs are of significance as they enable effective transmission of the parasite. This study, for the first time, characterizes the Ascaris egg profiles in human faeces in an endemic region of China, explores possible host- and parasite-factors related to these profiles, and discusses the biological and epidemiological implications of the findings. The 3 egg profiles were recorded throughout the study period of 2 years, and the overall percentages of people with FEO, FUE and UEO profiles were ~41–47%, 32–42% and 17–21%, respectively. The overall number of unfertilized eggs for the entire population accounted for ~6–9% of all eggs excreted. The different Ascaris egg profiles showed no correlation to host gender, but they did relate to age and worm burden of the host and to the sex ratio and developmental status of the parasite. While an annual universal anthelmintic treatment resulted in some fluctuation in the values of in idual egg profiles, the general features of these profiles remained similar throughout the study period. The findings of this study should have significant implications for understanding transmission patterns of Ascaris and for the implementation of control measures against ascariasis in endemic regions.
First human case of fatal Halicephalobus gingivalis meningoencephalitis in Australia.
Publisher: American Society for Microbiology
Date: 05-2015
DOI: 10.1128/JCM.00032-15
Abstract: Halicephalobus gingivalis (previously Micronema deletrix ) is a free-living nematode known to cause opportunistic infections, mainly in horses. Human infections are very rare, but all cases described to date involved fatal meningoencephalitis. Here we report the first case of H. gingivalis infection in an Australian human patient, confirmed by nematode morphology and sequencing of ribosomal DNA. The implications of this case are discussed, particularly, the need to evaluate real-time PCR as a diagnostic tool.
Practical PCR tools for the delineation of Contracaecum rudolphii A and Contracaecum rudolphii B (Ascaridoidea: Anisakidae) using genetic markers in nuclear ribosomal DNA
Publisher: Elsevier BV
Date: 04-2007
DOI: 10.1016/J.MCP.2006.08.004
Abstract: Using genetic markers defined previously in the internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA (rDNA), PCR-coupled restriction fragment length polymorphism (PCR-RFLP) and specific PCR assays were established for the specific detection of each of two morphologically indistinguishable operational taxonomic units (Contracaecum rudolphii A and Contracaecum rudolphii B) within Contracaecum rudolphii (s.l.) and their differentiation from Contracaecum septentrionale, a closely related congener. Application of these tools to C. rudolphii (s.l.) adults from Phalacrocorax carbo sinensis (the Eurasian subspecies of the great cormorant) from Qinghai Lake in China, revealed C. rudolphii B to infect this host. This is the first report of C. rudolphii B in P. carbo sinensis outside of Europe (where it was originally detected), supporting the proposal that this species has a broad geographical distribution. Together with other methods, each of these molecular tools will be useful for investigating the ecology of C. rudolphii A and C. rudolphii B as well as C. septentrionale.
Pipeline for the identification and classification of ion channels in parasitic flatworms
Publisher: Springer Science and Business Media LLC
Date: 16-03-2016
Trehalose 6‐phosphate phosphatases of Pseudomonas aeruginosa
Publisher: Wiley
Date: 24-04-2018
Evaluation and application of a molecular method to assess the composition of strongylid nematode populations in sheep with naturally acquired infections
Publisher: Elsevier BV
Date: 07-2011
DOI: 10.1016/J.MEEGID.2011.01.013
Abstract: We evaluated the performance of a PCR method for the diagnosis of naturally acquired strongylid nematode infections in sheep (n = 470 in a temperate climatic zone of south-eastern Australia), using a panel of 100 'negative control' s les from sheep known not to harbour parasitic helminths. We compared the diagnostic sensitivity (98%) and specificity (100%) of this assay against a conventional faecal flotation method and also established a system to rank the contribution of particular strongylid nematodes to the faecal egg counts (FECs) from 'mixed infections' in in idual sheep. The testing of faecal s les herein revealed that Teladorsagia circumcincta (80%) and Trichostrongylus spp. (66%) were most prevalent, followed by Chabertia ovina (33%), Oesophagostomum venulosum (28%) and Haemonchus contortus (1%). For the majority of sheep in this study, T. circumcincta and Trichostrongylus spp. represented the largest proportion of strongylid eggs in faecal s les from in idual sheep. This is the first large-scale prevalence survey of gastrointestinal nematodes in live sheep using a molecular tool. The ability to rapidly rank strongylid nematodes according to their contribution to mixed infections represents a major advantage over routine coprological methods. This PCR tool has the potential to replace the conventional technique of larval culture. Future efforts will focus on enhancing and adapting this molecular method for high throughput application in routine, diagnostic settings.
Recent insights into the epidemiology and genetics of Ascaris in China using molecular tools
Publisher: Cambridge University Press (CUP)
Date: 19-10-2006
[(eta(6)-Praziquantel)Cr(CO)(3)] Derivatives with Remarkable In Vitro Anti-schistosomal Activity
Publisher: Wiley
Date: 07-01-2013
Abstract: The antischistosomal effect of two [(η(6)-praziquantel)Cr(CO)(3)] derivatives was investigated. The compounds (see figure: Cr purple, N blue, O red) were prepared in a one-step procedure from commercially available praziquantel. Both derivatives show a high in vitro activity against Schistosoma mansoni, a parasitic trematode, and only a minor cytotoxic effect on selected mammalian cell lines.
Massively Parallel Sequencing and Analysis of the Necator americanus Transcriptome
Publisher: Public Library of Science (PLoS)
Date: 11-05-2010
Clear Genetic Distinctiveness between Human- and Pig-Derived Trichuris Based on Analyses of Mitochondrial Datasets
Publisher: Public Library of Science (PLoS)
Date: 21-02-2012
Survey of Cryptosporidium parvum genotypes in humans from the UK by mutation scanning analysis of a heat shock protein gene region
Publisher: Elsevier BV
Date: 08-2003
DOI: 10.1016/S0890-8508(03)00030-6
Abstract: A mutation scanning-selective sequencing approach was employed for the genotypic identification and differentiation of Cryptosporidium parvum isolates. Genomic DNA s les (n=158) from Cryptosporidium oocysts from humans with clinical cryptosporidiosis (following recent foreign travel or during different outbreaks) in the UK were subjected to PCR-based single-strand conformation polymorphism (SSCP) analysis of a heat shock protein 70 gene region (p-hsp70 448 bp). S les representing different SSCP profiles were then subjected to sequencing. The analysis allowed the classification of 149 of the 158 s les as type-1 ( approximately 49%) or type-2 ( approximately 46%) licons from the remaining nine s les were consistent in size with p-hsp70 but represented non-specific, faecal contaminants. The percentages reflected those of a previous study in the UK for autochtonous, sporadic cases of cryptosporidiosis ( approximately 49% for type-1 and approximately 47% for type-2 n approximately 4000), but contrasted another survey of sporadic cases where type-2 dominated ( approximately 62% n approximately 1000). The ability of the present SSCP-sequencing approach to accurately screen for C. parvum genotypes and to reliably discern erroneous licons has significant implications for the accurate diagnosis and monitoring of cryptosporidiosis and for population genetic studies.
A Deep Exploration of the Transcriptome and “Excretory/Secretory” Proteome of Adult Fascioloides magna
Publisher: Elsevier BV
Date: 11-2012
Screening of a small, well-curated natural product-based library identifies two rotenoids with potent nematocidal activity against Haemonchus contortus
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.VETPAR.2017.07.005
Abstract: The control of parasitic roundworms (nematodes) is heavily reliant on the use of a limited number of anthelmintic drugs. However, drug resistance is now very widespread and no vaccines are available, such that the discovery of new chemical entities is crucial. Within this context, we screened a library of pure natural products (n=400) against exsheathed third-stage (xL3) larvae of the parasitic nematode Haemonchus contortus using a whole-organism screening method. We identified two plant-derived rotenoids, deguelin and rotenone, with inhibitory activity on xL3 motility. Rotenone was not investigated further, because of its toxicity to some vertebrates. The dose response and cytotoxicity studies showed potent and selective inhibitory activity of deguelin on motility of xL3 larvae of H. contortus. Detailed future work needs to be conducted to explore the mode of action of this compound on H. contortus and related nematodes, and to assess its potential as an anthelmintic candidate.
DIFFERENCES IN A RIBOSOMAL DNA-SEQUENCE OF STRONGYLUS SPECIES ALLOWS IDENTIFICATION OF SINGLE EGGS
Publisher: Elsevier BV
Date: 03-1995
DOI: 10.1016/0020-7519(94)00116-6
Abstract: In the current study, molecular techniques were evaluated for the species identification of in idual strongyle eggs. Adult worms of Strongylus edentatus, S. equinus and S. vulgaris were collected at necropsy from horses from Australia and the U.S.A. Genomic DNA was isolated and a ribosomal transcribed spacer (ITS-2) lified and sequenced using polymerase chain reaction (PCR) techniques. The length of the ITS-2 sequence of S. edentatus, S. equinus and S. vulgaris ranged between 217 and 235 nucleotides. Extensive sequence analysis demonstrated a low degree (0-0.9%) of intraspecific variation in the ITS-2 for the Strongylus species examined, whereas the levels of interspecific differences (13-29%) were significantly greater. Interspecific differences in the ITS-2 sequences allowed unequivocal species identification of single worms and eggs using PCR-linked restriction fragment length polymorphism. These results demonstrate the potential of the ribosomal spacers as genetic markers for species identification of single strongyle eggs from horse faeces.
Synthesis, Characterization, and Biological Activity of Ferrocenyl Analogues of the Anthelmintic Drug Monepantel
Publisher: American Chemical Society (ACS)
Date: 21-09-2016
Population structure of Haemonchus contortus from seven geographical regions in China, determined on the basis of microsatellite markers
Publisher: Springer Science and Business Media LLC
Date: 15-11-2016
The Mitochondrial Genomics of Parasitic Nematodes of Socio-Economic Importance: Recent Progress, and Implications for Population Genetics and Systematics
Publisher: Elsevier
Date: 2003
DOI: 10.1016/S0065-308X(03)56003-1
Abstract: Mitochondria are subcellular organelles in which oxidative phosphorylation and other important biochemical functions take place within the cell. Within these organelles is a genome, called the mitochondrial (mt) genome, which is distinct from, but cooperates closely with the nuclear genome of the cell. Investigating mt genomes has significant implications for various fundamental research areas, including mt biochemistry and physiology, and, importantly, such genomes provide a rich source of markers for population genetic and systematic studies. While approximately 250 complete mt genome sequences have been determined for a range of metazoan organisms from various phyla, few of these represent parasitic helminths. Until 1998, only two mt genome sequences had been determined for parasitic nematodes, in spite of their socio-economic importance and the need for investigations into their population genetics, taxonomy and evolution. However, since that time, there has been some progress. The main focus of the present chapter is to review the state of knowledge of the mt genomics for parasitic nematodes, to describe recent technological improvements to mt genome sequencing, to summarize applications of mt gene markers for studying the systematics and population genetics of parasitic nematodes, and to emphasize prospects and opportunities for future research in these areas.
Rapid delineation of closely-related filarial parasites using genetic markers in spacer rDNA
Publisher: Elsevier BV
Date: 12-1996
DOI: 10.1016/S0001-706X(96)00035-6
Abstract: Two closely-related species of filarial parasite, Litomosoides galizai and L. sigmodontis, were characterised using a polymerase chain reaction-linked restriction fragment length polymorphism (PCR-RFLP) technique. The rDNA region spanning the first and second internal transcribed spacers as well as the 5.8S gene (ITS+) was lified by PCR from each of the species using conserved primers to the 18S and 28S ribosomal genes, digested separately with a range of restriction endonucleases and the fragments separated by agarose gel electrophoresis. PCR-RFLP of ITS+ using endonucleases Alu I, Cfo I, Dra I, Rsa I and Vsp I produced characteristic patterns for each species. No variation in RFLP patterns was detected among different DNA s le preparations or the sexes of each species. The present study demonstrates that the ITS+ provides genetic markers for the differentiation of L. galizai from L sigmodontis and suggests that internal transcribed spacer rDNA may provide species markers for other filarioid nematodes. Such markers have implications for diagnosis and for studying the biology, pathogenesis and systematics of filarial parasites.
Whole-genome sequence of the bovine blood fluke Schistosoma bovis supports interspecific hybridization with S. haematobium
Publisher: Public Library of Science (PLoS)
Date: 23-01-2019
Atypical (RIO) protein kinases from Haemonchus contortus — Promise as new targets for nematocidal drugs
Publisher: Elsevier BV
Date: 05-2011
DOI: 10.1016/J.BIOTECHADV.2011.01.006
Abstract: Almost nothing is known about atypical kinases in multicellular organisms, including parasites. Supported by information and data available for the free-living nematode, Caenorhabditis elegans, and other eukaryotes, the present article describes three RIO kinase genes, riok-1, riok-2 and riok-3, from Haemonchus contortus, one of the most important parasitic nematodes of small ruminants. Analyses of these genes and their products predict that they each play critical roles in the developmental pathways of parasitic nematodes. The findings of this review indicate prospects for functional studies of these genes in C. elegans (as a surrogate) and opportunities for the design of a novel class of nematode-specific inhibitors of RIO kinases. The latter aspect is of paramount importance, given the serious problems linked to anthelmintic resistance in parasitic nematode populations of livestock.
Bovine theileriosis - An emerging problem in south-eastern Australia?
Publisher: Elsevier BV
Date: 12-2011
DOI: 10.1016/J.MEEGID.2011.08.012
Abstract: Bovine theileriosis is an arthropod-borne disease caused by one or more haemoprotozoan parasites of the genus Theileria. Traditionally, Theileria infection in cattle in Australia was largely asymptomatic and recognized to be associated with Theileria buffeli, now assigned to the Theileria orientalis-group. There have been some recent outbreaks of theileriosis in dairy and beef cattle, mainly in subtropical climatic zone (New South Wales) of Australia. Here, we provide the first published evidence of an outbreak of bovine theileriosis in the south-eastern Australia (state of Victoria) linked to the ikeda and chitose genotypes of T. orientalis. Future investigations should focus sharply on the elucidating the epidemiology and ecology of Theileria in this region to subvert the possible impact on the cattle industry.
Infectivity of Swiss Giardia isolates to jirds and mice, and in vitro cultivation of trophozoites originating from sheep
Publisher: Springer Science and Business Media LLC
Date: 1987
DOI: 10.1007/BF00536020
Abstract: The 3xTg-AD mouse develops a progressive Alzheimer's disease- (AD-) like brain pathology that causes cognitive- and neuropsychiatric-like symptoms of dementia. Since its neuroimmunoendocrine axis is likewise impaired, this mouse is also useful for modelling complex age-related neurodegeneration. This study analyzed behavioral, physiological, neurochemical, pathological and immunoendocrine alterations in male and female 3xTg-AD mice and assayed the effects of a short therapy of forced physical exercise at the moderate pathology stage of 6 months of age. Gender effects were observed in most AD-related pathology and dysfunctions. Five weeks of treadmill training produced beneficial effects, such as the reduction of brain oxidative stress and GABA-A receptor dysfunction in males and improvement of sensorimotor function in females. In both sexes, exercise decreased the brain amyloid β 42/40 ratio levels. The results highlight the importance of analyzing experimental therapies in both mouse model genders in order to improve our understanding of the disease and develop more appropriate therapies.
The Transcriptome of Trichuris suis - First Molecular Insights into a Parasite with Curative Properties for Key Immune Diseases of Humans
Publisher: Public Library of Science (PLoS)
Date: 24-08-2011
Molecular characterization of Malassezia isolates from dogs using three distinct genetic markers in nuclear DNA
Publisher: Elsevier BV
Date: 06-2007
The prevalence and epidemiology of gastrointestinal parasites of horses in Victoria, Australia
Publisher: Elsevier BV
Date: 06-1995
DOI: 10.1016/0020-7519(94)00214-9
Abstract: A quantitative post mortem study of 150 horses from Victoria was conducted to determine the prevalence and epidemiology of gastrointestinal parasites. A total of 42 species of metazoan parasite was found. The following species of non-cyathostome parasite were found (% prevalence): Trichostrongylus axei (51%) Habronema muscae (13%) H. majus (2%) Draschia megastoma (5%) Gastreophilus intestinalis (81%) G. nasalis (29%) Parascaris equorum (5%) Anoplocephala perfoliata (29%) Fasciola hepatica (0.7%) Oxyuris equi (7%) Strongylu vulgaris (23%) S. edentatus (23%) S. equinus (3%) Craterostomum acuticaudatum (7%) Triodontophorus serratus (8%) T. tenuicollis (8%) T. brevicauda (3%). Ninety-five per cent of horses were infected with gut-wall encysted stages of cythostomes with a mean intensity of 113,000 larvae per horse. Ninety-three per cent of all horses harboured adult cyathosome worms 24 species representing 6 genera were found. The 3 most prevalent species were Cylicostephanus longiburstatus (76%) Cyathostomum catinatum (68%) and Cylicocyclus nassatus (54%). Seventeen species of strongyle were present in high abundance, which allowed their site distribution in the large intestine to be determined. Twelve species preferred the large colon to the small colon and caecum, and the remaining 5 species preferred the caecum. Statistical analysis of the parasitological data set allowed effects of sex, age, type, and physical condition of the horse as well as the season and environment on the prevalence and mean intensity of infection to be determined.
Assessing the anthelmintic activity of pyrazole-5-carboxamide derivatives against Haemonchus contortus.
Publisher: Springer Science and Business Media LLC
Date: 31-05-2017
Predominance of Streptococcus suis ST1 and ST7 in human cases in China, and detection of a novel sequence type, ST658
Publisher: Informa UK Limited
Date: 30-09-2016
Genomic characterization of Tv-ant-1, a Caenorhabditis elegans tag-61 homologue from the parasitic nematode Trichostrongylus vitrinus
Publisher: Elsevier BV
Date: 08-2007
DOI: 10.1016/J.GENE.2007.03.011
Abstract: A full-length cDNA (Tv-ant-1) encoding an adenine nucleotide translocator (ANT or ADP/ATP translocase) (Tv-ANT-1) was isolated from Trichostrongylus vitrinus (order Strongylida), an economically important parasitic nematode of small ruminants. The uninterrupted open reading frame (ORF) of 894 nucleotides encoded a predicted protein of 297 amino acids, containing characteristic motifs [RRRMMM] and PX(D,E)XX(K,R). Comparison with selected sequences from the free-living nematode Caenorhabditis elegans, cattle and human showed that Tv-ANT-1 is relatively conserved. Sequence identity was the greatest in and near the consensus sequence RRRMMM, and in the six hydrophobic regions predicted to be associated with alpha-helices and to traverse the cell membrane. Phylogenetic analyses of selected amino acid sequence data, using the neighbor-joining and maximum parsimony methods, revealed Tv-ANT-1 to be most closely related to the molecule (Ce-ANT-3) inferred from the tag-61 gene of C. elegans. Comparison of the genomic organization of the full-length Tv-ant-1 gene was similar to that of tag-61. Analysis of the region (5'-UTR) upstream of Tv-ant-1 identified some promoter components, including GATA transcription factor, CAAT and E-box elements. Transcriptional analysis by reverse transcription polymerase chain reaction (RT-PCR) showed that Tv-ant-1 was transcribed in all developmental stages of T. vitrinus, including the first- to fourth- stage larvae (L(1)-L(4)) as well as female and male adults. RNA interference, conducted by feeding C. elegans with double-stranded RNA (dsRNA) from Tv-ant-1 cDNA (using the homologous gene from C. elegans as a positive control), revealed no gene silencing. In spite of nucleotide identities of 100% in 23-30 bp stretches of sequence between the genes Tv-ant-1 and tag-61, these identities seem to be insufficient to achieve effective silencing in C. elegans using the parasite homologue/orthologue Tv-ant-1. This first insight into an ANT of T. vitrinus provides a foundation for exploring its role in developmental and/or survival processes of trichostrongylid nematodes.
Genome-Wide Analysis of Haemonchus contortus Proteases and Protease Inhibitors Using Advanced Informatics Provides Insights into Parasite Biology and Host–Parasite Interactions
Publisher: MDPI AG
Date: 08-2023
Abstract: Bio ersity within the animal kingdom is associated with extensive molecular ersity. The expansion of genomic, transcriptomic and proteomic data sets for invertebrate groups and species with unique biological traits necessitates reliable in silico tools for the accurate identification and annotation of molecules and molecular groups. However, conventional tools are inadequate for lesser-known organismal groups, such as eukaryotic pathogens (parasites), so that improved approaches are urgently needed. Here, we established a combined sequence- and structure-based workflow system to harness well-curated publicly available data sets and resources to identify, classify and annotate proteases and protease inhibitors of a highly pathogenic parasitic roundworm (nematode) of global relevance, called Haemonchus contortus (barber’s pole worm). This workflow performed markedly better than conventional, sequence-based classification and annotation alone and allowed the first genome-wide characterisation of protease and protease inhibitor genes and gene products in this worm. In total, we identified 790 genes encoding 860 proteases and protease inhibitors representing 83 gene families. The proteins inferred included 280 metallo-, 145 cysteine, 142 serine, 121 aspartic and 81 “mixed” proteases as well as 91 protease inhibitors, all of which had marked physicochemical ersity and inferred involvements in biological processes or pathways. A detailed investigation revealed a remarkable expansion of some protease or inhibitor gene families, which are likely linked to parasitism (e.g., host–parasite interactions, immunomodulation and blood-feeding) and exhibit stage- or sex-specific transcription profiles. This investigation provides a solid foundation for detailed explorations of the structures and functions of proteases and protease inhibitors of H. contortus and related nematodes, and it could assist in the discovery of new drug or vaccine targets against infections or diseases.
Mutation scanning-coupled tools for the analysis of genetic variation in Taenia and diagnosis - Status and prospects
Publisher: Elsevier BV
Date: 09-2009
DOI: 10.1016/J.MEEGID.2009.05.005
Abstract: Cestodes of the genus Taenia occur as adult tapeworms in the small intestine of carnivorous definitive hosts and are transmitted to particular mammalian intermediate hosts, in which they develop as fluid-filled larvae in tissues, causing the disease cysticercosis or coenuriasis. A number of species are of medical importance and/or cause losses to the meat and livestock industry mainly due to the condemnation of infected muscle and offal. The control of taeniid cestodes relies upon epidemiological data, including the precise identification and characterization of the causative agents. Traditional, phenetic techniques have limitations for specific diagnosis. Although there has been progress in the establishment of molecular tools, there has been relatively limited application of mutation scanning approaches to species of Taenia. In the present article, we briefly review key genetic markers used for the specific identification of taeniids and tools for the analysis of genetic variation within and among populations and the diagnosis of taeniasis and cysticercosis/coenuriasis. We also discuss the advantages and disadvantages of selected techniques and emphasize the benefits of utilizing mutation scanning-based approaches in achieving detailed insights into the population genetics and epidemiology of Taenia species.
NADH dehydrogenase subunit 1 and cytochrome c oxidase subunit I sequences compared for members of the genus Taenia (Cestoda)
Publisher: Elsevier BV
Date: 12-1999
DOI: 10.1016/S0020-7519(99)00153-8
Abstract: Nine members of the genus Taenia (Taenia taeniaeformis, Taenia hydatigena, Taenia pisiformis, Taenia ovis, Taenia multiceps, Taenia serialis, Taenia saginata, Taenia solium and the Asian Taenia) were characterised by their mitochondrial NADH dehydrogenase subunit 1 gene sequences and their genetic relationships were compared with those derived from the cytochrome c oxidase subunit 1 sequence data. The extent of inter-taxon sequence difference in NADH dehydrogenase subunit 1 (approximately 5.9-30.8%) was usually greater than in cytochrome c oxidase subunit 1 (approximately 2.5-18%). Although topology of the phenograms derived from NADH dehydrogenase subunit 1 and cytochrome c oxidase subunit 1 sequence data differed, there was concordance in that T. multiceps, T. serialis (of canids), T. saginata and the Asian Taenia (of humans) were genetically most similar, and those four members were genetically more similar to T. ovis and T. solium than they were to T. hydatigena and T. pisiformis (of canids) or T. taeniaeformis (of cats). The NADH dehydrogenase subunit 1 sequence data may prove useful in studies of the systematics and population genetic structure of the Taeniidae.
The occurrence of Toxocara malaysiensis in cats in China, confirmed by sequence-based analyses of ribosomal DNA
Publisher: Springer Science and Business Media LLC
Date: 25-04-2006
DOI: 10.1007/S00436-006-0194-Z
Abstract: Non-isotopic polymerase chain reaction (PCR)-based single-strand conformation polymorphism and sequence analyses of the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA (rDNA) were utilized to genetically characterise ascaridoids from dogs and cats from China by comparison with those from other countries. The study showed that Toxocara canis, Toxocara cati, and Toxascaris leonina from China were genetically the same as those from other geographical origins. Specimens from cats from Guangzhou, China, which were morphologically consistent with Toxocara malaysiensis, were the same genetically as those from Malaysia, with the exception of a polymorphism in the ITS-2 but no unequivocal sequence difference. This is the first report of T. malaysiensis in cats outside of Malaysia (from where it was originally described), supporting the proposal that this species has a broader geographical distribution. The molecular approach employed provides a powerful tool for elucidating the biology, epidemiology, and zoonotic significance of T. malaysiensis.
First transcriptomic analysis of the economically important parasitic nematode, Trichostrongylus colubriformis, using a next-generation sequencing approach
Publisher: Elsevier BV
Date: 12-2010
Molecular diagnosis of sparganosis associated with pneumothorax in a dog
Publisher: Elsevier BV
Date: 02-2012
DOI: 10.1016/J.MCP.2011.08.003
Abstract: Pneumothorax was diagnosed in a dog presenting with progressive exercise intolerance and tachypnoea. Needle thoracocentesis failed to resolve the pneumothorax, and an exploratomy thoracotomy was performed. Upon inspection of the thoracic cavity, numerous white nodules (2 to 4mm) were present throughout the mediastinum, parietal pleura and the lung lobes. The owners of the dog elected intra-operative euthanasia, and a post mortem examination was performed. At necropsy, structures consistent with the plerocercoid (larval) stage of a tapeworm were identified in association with inflammation of the pleural cavity. Molecular methods were used to identify the parasite as Spirometra erinacei. Molecular diagnosis, along with the clinical presentation and pathological findings, allowed the diagnosis of proliferative sparganosis.
A Perspective on cryptosporidium and giardia, with an emphasis on bovines and recent epidemiological findings
Publisher: Elsevier
Date: 2015
Prospects for vector-based gene silencing to explore immunobiological features of schistosoma mansoni
Publisher: Elsevier
Date: 2015
DOI: 10.1016/BS.APAR.2015.02.002
Abstract: Schistosomiasis is a prevalent, socioeconomically important disease of humans caused by parasites of the genus Schistosoma (schistosomes or blood flukes). Currently, more than 200 million people worldwide are infected with schistosomes. Despite major research efforts, there is only one drug routinely used for effective treatment, and no vaccine is available to combat schistosomiasis. The purpose of the present article is to (1) provide a background on the parasites and different forms of disease (2) describe key immunomolecular aspects of disease induced in the host and (3) critically appraise functional genomic methods employed to explore parasite biology, parasite-host interactions and disease at the molecular level. Importantly, the article also describes the features and advantages of lentiviral delivery of artificial microRNAs to silence genes. It also discusses the first successful application of such an approach in schistosomes, in order to explore the immunobiological role of selected target proteins known to be involved in egg-induced disease. The lentiviral transduction system provides exciting prospects for future, fundamental investigations of schistosomes, and is likely to have broad applicability to other eukaryotic pathogens and infectious diseases. The ability to achieve effective and stable gene perturbation in parasites has major biotechnological implications, and might facilitate the development of radically new methods for the treatment and control of parasitic diseases.
Molecular systematics and diagnosis
Publisher: Elsevier BV
Date: 10-2004
Multifocal Balamuthia mandrillaris infection in a dog in Australia
Publisher: Springer Science and Business Media LLC
Date: 11-10-2007
DOI: 10.1007/S00436-006-0302-0
Abstract: A 6-year-old male golden retriever, with an 8-month history of seizures and a clinical diagnosis of lymphoma in the central nervous system, was (at the owner's request) euthanized after signs of respiratory distress and shock developed. Upon postmortem examination, the diagnoses of meningoencephalitis and pneumonia were made. A histological examination of selected tissues from both the lung and central nervous system revealed a severe, acute, multifocal, amoebic, embolic pneumonia and a severe, chronic, multifocal, nonsuppurative, amoebic meningoencephalitis. Indirect immunofluorescence analysis confirmed the presence of trophozoite and cyst stages of Balamuthia mandrillaris. This is the first report of B. mandrillaris (which is a free-living amoeba) causing fatal, multifocal granulomatous amoebiasis in a dog in Australia.
Transcriptional analysis identifies key genes involved in metabolism, fibrosis/tissue repair and the immune response against Fasciola hepatica in sheep liver
Publisher: Springer Science and Business Media LLC
Date: 25-02-2015
Marked mitochondrial genetic variation in individuals and populations of the carcinogenic liver fluke Clonorchis sinensis
Publisher: Public Library of Science (PLoS)
Date: 19-08-2020
Reproductive characteristics of a precocious vaccine line (Rt3+15) of Eimeria tenella in embryonating chicken eggs
Publisher: Walter de Gruyter GmbH
Date: 2006
DOI: 10.2478/S11686-006-0024-6
Abstract: Coccidiosis of chickens, caused by species of Eimeria (Protozoa, Apicomplexa), is an intestinal disease of major economic importance worldwide. In the present study, the reproductive characteristics of a precocious line (designated E. tenella Rt3+15) from Australia were investigated in chicken embryos and the implications of the findings briefly discussed.
The mitochondrial genome of Strongyloides stercoralis (Nematoda) – idiosyncratic gene order and evolutionary implications
Publisher: Elsevier BV
Date: 10-2003
DOI: 10.1016/S0020-7519(03)00130-9
Abstract: The complete mitochondrial genome sequence of the parasitic nematode Strongyloides stercoralis was determined, and its organisation and structure compared with other nematodes for which complete mitochondrial sequence data were available. The mitochondrial genome of S. stercoralis is 13,758 bp in size and contains 36 genes (all transcribed in the clockwise direction) but lacks the atp8 gene. This genome has a high T content (55.9%) and a low C content (8.3%). Corresponding to this T content, there are 16 (poly-T) tracts of >/=12 Ts distributed across the genome. In protein-coding genes, the T bias is greatest (76.4%) at the third codon position compared with the first and second codon positions. Also, the C content is higher at the first (9.3%) and second (13.4%) codon positions than at the third (2%) position. These nucleotide biases have a significant effect on predicted codon usage patterns and, hence, on amino acid compositions of the mitochondrial proteins. Interestingly, six of the 12 protein-coding genes are predicted to employ a unique initiation codon (TTT), which has not yet been reported for any other animal mitochondrial genome. The secondary structures predicted for the 22 transfer RNA (trn) genes and the two ribosomal RNA (rrn) genes are similar to those of other nematodes. In contrast, the gene arrangement in the mitochondrial genome of S. stercoralis is different from all other nematodes studied to date, revealing only a limited number of shared gene boundaries (atp6-nad2 and cox2-rrnL). Evolutionary analyses of mitochondrial nucleotide and amino acid sequence data sets for S. stercoralis and seven other nematodes demonstrate that the mitochondrial genome provides a rich source of phylogenetically informative characters. In conclusion, the S. stercoralis mitochondrial genome, with its unique gene order and characteristics, should provide a resource for comparative mitochondrial genomics and systematics studies of parasitic nematodes.
PFresGO: an attention mechanism-based deep-learning approach for protein annotation by integrating gene ontology inter-relationships
Publisher: Oxford University Press (OUP)
Date: 16-02-2023
DOI: 10.1093/BIOINFORMATICS/BTAD094
Abstract: The rapid accumulation of high-throughput sequence data demands the development of effective and efficient data-driven computational methods to functionally annotate proteins. However, most current approaches used for functional annotation simply focus on the use of protein-level information but ignore inter-relationships among annotations. Here, we established PFresGO, an attention-based deep-learning approach that incorporates hierarchical structures in Gene Ontology (GO) graphs and advances in natural language processing algorithms for the functional annotation of proteins. PFresGO employs a self-attention operation to capture the inter-relationships of GO terms, updates its embedding accordingly and uses a cross-attention operation to project protein representations and GO embedding into a common latent space to identify global protein sequence patterns and local functional residues. We demonstrate that PFresGO consistently achieves superior performance across GO categories when compared with ‘state-of-the-art’ methods. Importantly, we show that PFresGO can identify functionally important residues in protein sequences by assessing the distribution of attention weightings. PFresGO should serve as an effective tool for the accurate functional annotation of proteins and functional domains within proteins. PFresGO is available for academic purposes at github.com/BioColLab/PFresGO. Supplementary data are available at Bioinformatics online.
Identification of parasitic nematodes by PCR-SSCP of ITS-2 rDNA
Publisher: Elsevier BV
Date: 06-1997
Abstract: Fourteen species of parasitic nematodes (order Strongylida) were characterized using a polymerase chain reaction-linked single strand conformation polymorphism technique (PCR-SSCP). The rDNA region spanning the second internal transcribed spacer (ITS-2) was lified from parasite DNA by PCR. The PCR products were then denatured and subjected to electrophoresis on a non-denaturing gel matrix. PCR-SSCP of the single stranded ITS-2 molecules generated characteristic and reproducible patterns for each species, and allowed the rapid delineation of all of the 14 species in one step. The method also allowed the display of variation in patterns within some species between different geographical isolates. These findings demonstrate the usefulness of PCR-SSCP of ITS-2 for the rapid identification of nematode species and indicate its potential for resolving variation in the ITS-2 sequence within a species.
Selenophene and thiophene-core estrogen receptor ligands that inhibit motility and development of parasitic stages of Haemonchus contortus
Publisher: Springer Science and Business Media LLC
Date: 16-06-2016
Dysidenin from the Marine Sponge Citronia sp. Affects the Motility and Morphology of Haemonchus contortus Larvae In Vitro
Publisher: MDPI AG
Date: 09-12-2021
DOI: 10.3390/MD19120698
Abstract: High-throughput screening of the NatureBank marine extract library (n = 7616) using a phenotypic assay for the parasitic nematode Haemonchus contortus identified an active extract derived from the Australian marine sponge Citronia sp. Bioassay-guided fractionation of the CH2Cl2/MeOH extract from Citronia sp. resulted in the purification of two known hexachlorinated peptides, dysidenin (1) and dysideathiazole (2). Compound 1 inhibited the growth/development of H. contortus larvae and induced multiple phenotypic changes, including a lethal evisceration (Evi) phenotype and/or somatic cell and tissue destruction. This is the first report of anthelmintic activity for these rare and unique polychlorinated peptides.
Quantitative PCR-Based Diagnosis of Soil-Transmitted Helminth Infections: Faecal or Fickle?
Publisher: Elsevier BV
Date: 07-2019
Abstract: Treatment and control programmes tackling soil-transmitted helminth (STH) infections require sensitive, reliable, and accurate diagnostic tools. There is a growing need for measures of infection intensity as programmes approach STH control. Quantitative real-time PCR (qPCR) is well suited to the detection of DNA targets present in stool, even in low-prevalence settings. Detecting low levels of infection becomes increasingly important when the breakpoint of transmission is approached, and is vital when monitoring for recrudescence once control, or possibly 'elimination', is achieved. We address key challenges and questions that remain as barriers to incorporating qPCR as a cornerstone diagnostic tool for STH infections.
Species identification of trichostrongyle nematodes by pcr-linked rflp
Publisher: Elsevier BV
Date: 04-1994
DOI: 10.1016/0020-7519(94)90041-8
Abstract: Restriction fragment length polymorphisms (RFLP) of the second internal transcribed spacer (ITS-2) of ribosomal DNA were examined for 6 species of ruminant nematodes Trichostrongylus colubriformis, T. axei, T. vitrinus, Haemonchus contortus, Teladorsagia circumcincta and Cooperia oncophora. The ITS-2 of each species was lified by PCR and restricted with the endonucleases DraI, HinfI, RsaI and VspI. Using this approach, the 6 species could be distinguished. No intraspecific variation in RFLP's has been detected so far in the ITS-2 of these species, suggesting that this technique has considerable potential for the identification of eggs of different nematode species in faecal s les.
Parasites of the Giant Panda: A Risk Factor in the Conservation of a Species
Publisher: Elsevier
Date: 2018
Isolation and characterization of class II myosin genes from Haemonchus contortus
Publisher: Springer Science and Business Media LLC
Date: 18-03-2006
DOI: 10.1007/S00436-006-0129-8
Abstract: In this study, cDNAs encoding myosin from the parasitic nematode Haemonchus contortus were isolated and characterized. Several exhibited a considerable degree of sequence variation at the nucleotide and limited ergence at the amino acid levels within the various functional domains. The results suggest that the cDNAs isolated represented a single myosin heavy chain, which, by comparison with a number of other myosins, is inferred to represent a homologue of a muscle myosin (CeMHCA) of the free-living nematode Caenorhabditis elegans. The findings could have implications for investigating cytoskeletal dynamics and/or signalling pathways.
Genetic variants of Malassezia pachydermatis from canine skin: body distribution and phospholipase activity
Publisher: Oxford University Press (OUP)
Date: 22-02-2008
DOI: 10.1111/J.1567-1364.2008.00358.X
Abstract: Malassezia pachydermatis isolates (n=185) from skin sites from dogs (n=30) were characterized genetically and biochemically following in vitro culture. Two regions in the chitin synthase-2 gene (chs-2) and the first internal transcribed spacer (ITS-1) of nuclear ribosomal DNA were sequenced, and the phospholipase activity of each isolate was assessed. Three chs-2 (i.e. Ac, Bc and Cc) and eight ITS-1 (i.e. AI1, AI2, AI3, AI4, BI1, CI1, CI2 and CI3) sequence types were defined for all 185 s les. The findings revealed that multiple M. pachydermatis genotypes/subgenotypes could be cultured from healthy dogs or from dogs with single or multiple, generalized skin lesions. Subgenotypes AI1 and BI1 were associated with all skin sites of dogs s led, whereas subgenotype CI2 was mostly linked to a particular location. Isolates derived from skin lesions showed a significantly higher phospholipase activity compared with those from skin sites with no detectable lesions. Genotype B was mainly cultured from healthy skin only four isolates (9.3%) had low phospholipase activity, whereas other genotypes/subgenotypes were predominantly associated with skin lesions and had a high phospholipase activity. The results of the present study suggest that the distribution pattern of particular genotypes or subgenotypes of M. pachydermatis on the skin of dogs relates to the affinity of the yeast to the host and to particular skin sites.
Profiling of gender-specific gene expression for Trichostrongylus vitrinus (Nematoda: Strongylida) by microarray analysis of expressed sequence tag libraries constructed by suppressive-subtractive hyb
Publisher: Elsevier BV
Date: 04-2004
An improved ‘cold SSCP’ method for the genotypic and subgenotypic characterization of Cryptosporidium
Publisher: Elsevier BV
Date: 10-2004
Prospects of Using High-Throughput Proteomics to Underpin the Discovery of Animal Host–Nematode Interactions
Publisher: MDPI AG
Date: 30-06-2021
DOI: 10.3390/PATHOGENS10070825
Abstract: Parasitic nematodes impose a significant public health burden, and cause major economic losses to agriculture worldwide. Due to the widespread of anthelmintic resistance and lack of effective vaccines for most nematode species, there is an urgent need to discover novel therapeutic and vaccine targets, informed through an understanding of host–parasite interactions. Proteomics, underpinned by genomics, enables the global characterisation proteins expressed in a particular cell type, tissue and organism, and provides a key to insights at the host–parasite interface using advanced high-throughput mass spectrometry-based proteomic technologies. Here, we (i) review current mass-spectrometry-based proteomic methods, with an emphasis on a high-throughput ‘bottom-up’ approach (ii) summarise recent progress in the proteomics of parasitic nematodes of animals, with a focus on molecules inferred to be involved in host–parasite interactions and (iii) discuss future research directions that could enhance our knowledge and understanding of the molecular interplay between nematodes and host animals, in order to work toward new, improved methods for the treatment, diagnosis and control of nematodiases.
Molecular detection of Cryptosporidium cuniculus in rabbits in Australia
Publisher: Elsevier BV
Date: 12-2010
DOI: 10.1016/J.MEEGID.2010.07.020
Abstract: In the United Kingdom, rabbits have been reported to harbour genotypes of Cryptosporidium (now recognized as C. cuniculus) identical to those from human patients exhibiting symptoms of cryptosporidiosis. The high density of rabbits in many regions of Australia, including both rural and urban as well as natural water catchments areas, and the absence of any information on Cryptosporidium from lagomorphs in this country stimulated the present study. We undertook an epidemiological study that genetically characterized Cryptosporidium from rabbits from four locations in Victoria by PCR-coupled sequencing and phylogenetic analysis of sequence data for loci within the small subunit of nuclear ribosomal RNA (SSU for specific identification) and the 60kDa glycoprotein gene (gp60 for genotypic/subgenotypic identification). Cryptosporidium was detected in 12 (6.8%) of 176 in idual faecal s les. For SSU, all 12 sequences were identical to each other and to that of C. cuniculus. For pgp60, all corresponding sequences matched the known genotype Vb, and were classified as subgenotype VbA23R3 (n=11) and VbA26R4 (n=1), which are both new records. Present evidence indicates that genotype Vb is limited to rabbits however, it would be premature to conclude that this genotype is not zoonotic. Future studies should focus on the zoonotic potential of C. cuniculus from rabbits and a wide range of yet unstudied animals. (Nucleotide sequences reported in this paper are available in the GenBank database under accession nos. HM852431-HM852433).
Immunological assessment of exposure to Echinococcus granulosus in a rural dog population in Uruguay
Publisher: Elsevier BV
Date: 12-1994
DOI: 10.1016/0001-706X(94)90012-4
Abstract: An ELISA was used to screen a dog population in Uruguay (Sarandi Del Yi, Durazno District) for the prevalence of specific serum antibodies (IgG, IgA and IgE) to Echinococcus granulosus. The sensitivity (61%) and specificity (97%) of the ELISA were determined using well-defined serum groups. A total of 408 dogs from Sarandi del Yi and environs were screened serologically, and 29.7% (8.6-13.8% for each antibody class) of dogs had positive levels of antibody to E. granulosus. This antibody prevalence (exposure) was significantly higher than the percentage of dogs found to be positive for E. granulosus worms by arecoline purgation (7.6%). This level of exposure to E. granulosus determined by ELISA is considered unacceptable from a public health perspective. Measures will now focus on obtaining data on the true prevalence of current infection in this dog population and on determining the transmission patterns of the disease in this endemic region.
A practical, bioinformatic workflow system for large data sets generated by next-generation sequencing
Publisher: Oxford University Press (OUP)
Date: 03-08-2010
DOI: 10.1093/NAR/GKQ667
Proteomic Analysis of Oesophagostomum dentatum (Nematoda) during Larval Transition, and the Effects of Hydrolase Inhibitors on Development
Publisher: Public Library of Science (PLoS)
Date: 22-05-2013
Serum antibodies in canine echinococcosis
Publisher: Elsevier BV
Date: 08-1993
DOI: 10.1016/0020-7519(93)90163-S
Abstract: Specific IgG, IgA and IgE antibodies against E. granulosus protoscolex antigen were detected by enzyme-linked immunosorbent assay (ELISA) in sera from dogs experimentally or naturally infected with E. granulosus. The specificities of the IgG, IgA and IgE ELISAs were 100, 100 and 97.3%, respectively. Sera from 626 dogs of different categories and geographic regions in Australia, Uruguay and Kenya were tested. There were distinct differences in antibody responses in experimentally infected canids and in the number of naturally infected dogs found seropositive, depending on geographic region. The overall sensitivities of the ELISA (IgG, IgA and IgE) ranged between 73 and 84%, except for one geographic region where it was 54%. Genetic differences of the dogs and/or antigenic variations of the parasite appear to be responsible for the variations in specific antibody levels in infected dogs. In average, approximately one third of dogs from hyperendemic hydatid regions, without E. granulosus worms at autopsy or negative for E. granulosus infection by arecoline testing, were seropositive for anti-E. granulosus antibodies, suggesting previous infection with or exposure to the parasite. The results of this study demonstrate that, although the diagnosis of current intestinal E. granulosus infection on an in idual dog basis is not always reliable by serology, serum antibody ELISA is useful as an epidemiological/educational tool for seroprevalence studies on canine echinococcosis.
A Molecular Diagnostic Tool to Replace Larval Culture in Conventional Faecal Egg Count Reduction Testing in Sheep
Publisher: Public Library of Science (PLoS)
Date: 22-05-2012
Time-course study of the transcriptome of peripheral blood mononuclear cells (PBMCs) from sheep infected with Fasciola hepatica
Publisher: Public Library of Science (PLoS)
Date: 20-07-2016
Molecular and immunological characterisation of tropomyosin from Anisakis pegreffii
Publisher: Springer Science and Business Media LLC
Date: 16-10-2017
DOI: 10.1007/S00436-017-5642-4
Abstract: Tropomyosin (TM) is a major allergen in shellfish, known to cross-react with mite, cockroach and/or some roundworm (nematode) TM. In this study, we aimed to express and purify TM from the parasitic nematode Anisakis pegreffii and also to characterise its cross-reactivity with TM from shellfish. A. pegreffii was isolated from the flathead tiger fish (Neoplatycephalus richardsoni) and characterised using single-strand conformation polymorphism (SSCP)-based sequencing of the first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA. The recombinant tropomyosin (rTM) of A. pegreffii was expressed, purified and confirmed by immunohistochemistry, sequencing and LC-MS/MS analyses. Immunohistochemistry showed the muscle and the base layer of the third-stage larvae (L3) of A. pegreffii as the location of TM in A. pegreffii. The molecular relationship of TM of A. pegreffii with homologs from other nematodes and crustaceans was inferred from phylogenetic analysis. Immunogenicity of TM from A. pegreffii was tested by immunoblotting, which showed that rTM from A. pegreffii binds to IgE from sera of patients with allergy to crustaceans. Immunoblotting also showed that the anti-TM monoclonal antibody (MAb) did not recognise rTM from A. pegreffii. The rTM from A. pegreffii was, however, recognised by anti-TM polyclonal antibodies (PAbs) as well as anti-crustacean polyclonal antibodies (PAbs). The detection of specific serum IgE antibody against parasite TM has been proposed as a useful approach for the diagnosis of parasite-induced allergy. The findings of this study merit further exploration of the cross-reactive allergenic proteins of Anisakis for improved, future diagnosis of allergenic diseases.
Chromosome-scale Echinococcus granulosus (genotype G1) genome reveals the Eg95 gene family and conservation of the EG95-vaccine molecule
Publisher: Springer Science and Business Media LLC
Date: 03-03-2022
DOI: 10.1038/S42003-022-03125-1
Abstract: Cystic echinococcosis is a socioeconomically important parasitic disease caused by the larval stage of the canid tapeworm Echinococcus granulosus , afflicting millions of humans and animals worldwide. The development of a vaccine (called EG95) has been the most notable translational advance in the fight against this disease in animals. However, almost nothing is known about the genomic organisation/location of the family of genes encoding EG95 and related molecules, the extent of their conservation or their functions. The lack of a complete reference genome for E. granulosus genotype G1 has been a major obstacle to addressing these areas. Here, we assembled a chromosomal-scale genome for this genotype by scaffolding to a high quality genome for the congener E. multilocularis , localised Eg 95 gene family members in this genome, and evaluated the conservation of the EG95 vaccine molecule. These results have marked implications for future explorations of aspects such as developmentally-regulated gene transcription/expression (using replicate s les) for all E. granulosus stages structural and functional roles of non-coding genome regions molecular ‘cross-talk’ between oncosphere and the immune system and defining the precise function(s) of EG95. Applied aspects should include developing improved tools for the diagnosis and chemotherapy of cystic echinococcosis of humans.
Assessment of sequence variability in a p23 gene region within and among three genotypes of the Theileria orientalis complex from south-eastern Australia
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.TTBDIS.2014.10.006
Abstract: Oriental theileriosis is a tick-borne, protozoan disease of cattle caused by one or more genotypes of Theileria orientalis complex. In this study, we assessed sequence variability in a region of the 23kDa piroplasm membrane protein (p23) gene within and among three T. orientalis genotypes (designated buffeli, chitose and ikeda) in south-eastern Australia. Genomic DNA (n=100) was extracted from blood of infected cattle from various locations endemic for oriental theileriosis and tested by polymerase chain reaction (PCR)-coupled mutation scanning (single-strand conformation polymorphism (SSCP)) and targeted sequencing analysis. Eight distinct sequences represented all DNA s les, and three genotypes were found: buffeli (n=3), chitose (3) and ikeda (2). Nucleotide pairwise comparisons among these eight sequences revealed considerably higher variability among the genotypes (6.6-11.7%) than within them (0-1.9%), indicating that the p23 gene region allows the accurate identification of T. orientalis genotypes. In the future, we will combine this gene with other molecular markers to study the genetic structure of T. orientalis populations in Australasia, which will pave the way to establish a highly sensitive and specific PCR-based assay for genotypic diagnosis of infection and for assessing levels of parasitaemia in cattle.
Genetic characterization of selected parasites from people with histories of gastrointestinal disorders using a mutation scanning-coupled approach
Publisher: Wiley
Date: 26-05-2013
Abstract: A SSCP analysis and targeted sequencing approach was used for the genetic characterization of some major pathogens from a cohort of 227 people with histories of gastrointestinal disorders. Genomic DNAs from fecal s les were subjected to PCR- lification of regions in the glycoprotein (gp60) or triose phosphate isomerase (tpi) gene, or the second internal transcribed spacer of nuclear ribosomal DNA (ITS-2). Cryptosporidium, Giardia, and strongylid nematodes were detected in 94, 132 and 12 s les. Cryptosporidium hominis subgenotypes IbA10G2, IdA15G1, IgA17, IgA18, and IfA13G1 were identified in 74.6, 16.9, 5.6, 1.4, and 1.4% of 71 s les, respectively. For Cryptosporidium parvum, subgenotypes IIaA17G2R1 (47.6%) and IIaA18G3R1 (23.8%) were identified in 23 s les. Giardia duodenalis assemblage B (78%) was more common than assemblage A (22%). In addition, DNA of the nematodes Ancylostoma ceylanicum (n = 2), Ancylostoma duodenale (4), Necator americanus (5), and Haemonchus contortus (1) was specifically detected. This is the first report of A. ceylanicum in two persons in Australia and, we provide molecular evidence of H. contortus in a child. This SSCP-based approach should provide a useful diagnostic and analytical tool for a wide range of pathogens.
Review of Papillostrongylus Johnston & Mawson, 1939 (Nematoda: Strongyloidea) from wallabies and kangaroos (Marsupialia: Macropodidae) using morphological and molecular techniques, with the description of P. barbatus n. sp.
Publisher: Springer Science and Business Media LLC
Date: 02-2002
Abstract: The strongyloid nematode genus Papillostrongylus Johnston & Mawson, 1939, from kangaroos and wallabies, is reviewed using morphological and molecular methods. P. labiatus Johnston & Mawson, 1939 is re-described from material from the type-host, the black-striped wallaby Macropus dorsalis, from eastern Queensland, Australia, in which it is a relatively common parasite. Additional records from M. parryi and Thylogale thetis are confirmed and considered to represent ex les of host-switching. A geographically disjunct population of the nematode species occurs in M. bernardus and Petrogale brachyotis in Arnhem Land, Northern Territory, but assessment of its status requires additional material. Nematodes from M. rufus, M. giganteus, M. fuliginosus and M. robustus from inland regions of Australia, formerly attributed to P. labiatus, are here assigned to a new species, P. barbatus, distinguished by the presence of an external leaf-crown, larger size, by greater spicule length in the male and by a sinuous vagina in the female. Additional hosts of P. barbatus n. sp. are Petrogale assimilis and Pet. lateralis purpureicollis. Sequence analyses of the second internal transcribed spacer of ribosomal DNA (ITS-2) also showed that P. barbatus n. sp. differed at 40 (16.7%) of the 240 alignment positions when compared with P. labiatus. Most of these interspecific sequence differences occurred in loops or bulges of the predicted precursor rRNA secondary structure, or represented partial or total compenstory base pair changes in stems.
Molecular evidence for distinct modes of nutrient acquisition between visceral and neurotropic schistosomes of birds
Publisher: Springer Science and Business Media LLC
Date: 04-02-2019
DOI: 10.1038/S41598-018-37669-2
Abstract: Trichobilharzia species are parasitic flatworms (called schistosomes or flukes) that cause important diseases in birds and humans, but very little is known about their molecular biology. Here, using a transcriptomics-bioinformatics-based approach, we explored molecular aspects pertaining to the nutritional requirements of Trichobilharzia szidati (‘visceral fluke’) and T . regenti (‘neurotropic fluke’) in their avian host. We studied the larvae of each species before they enter (cercariae) and as they migrate (schistosomules) through distinct tissues in their avian (duck) host. Cercariae of both species were enriched for pathways or molecules associated predominantly with carbohydrate metabolism, oxidative phosphorylation and translation of proteins linked to ribosome biogenesis, exosome production and/or lipid biogenesis. Schistosomules of both species were enriched for pathways or molecules associated with processes including signal transduction, cell turnover and motility, DNA replication and repair, molecular transport and/or catabolism. Comparative informatic analyses identified molecular repertoires (within, e.g., peptidases and secretory proteins) in schistosomules that can broadly degrade macromolecules in both T. szidati and T. regenti , and others that are tailored to each species to selectively acquire nutrients from particular tissues through which it migrates. Thus, this study provides molecular evidence for distinct modes of nutrient acquisition between the visceral and neurotropic flukes of birds.
Transcriptome analyses reveal protein and domain families that delineate stage-related development in the economically important parasitic nematodes, Ostertagia ostertagi and Cooperia oncophora
Publisher: Springer Science and Business Media LLC
Date: 22-02-2013
Abstract: Cooperia oncophora and Ostertagia ostertagi are among the most important gastrointestinal nematodes of cattle worldwide. The economic losses caused by these parasites are on the order of hundreds of millions of dollars per year. Conventional treatment of these parasites is through anthelmintic drugs however, as resistance to anthelmintics increases, overall effectiveness has begun decreasing. New methods of control and alternative drug targets are necessary. In-depth analysis of transcriptomic data can help provide these targets. The assembly of 8.7 million and 11 million sequences from C. oncophora and O. ostertagi , respectively, resulted in 29,900 and 34,792 transcripts. Among these, 69% and 73% of the predicted peptides encoded by C. oncophora and O. ostertagi had homologues in other nematodes. Approximately 21% and 24% were constitutively expressed in both species, respectively however, the numbers of transcripts that were stage specific were much smaller (~1% of the transcripts expressed in a stage). Approximately 21% of the transcripts in C. oncophora and 22% in O. ostertagi were up-regulated in a particular stage. Functional molecular signatures were detected for 46% and 35% of the transcripts in C. oncophora and O. ostertagi , respectively. More in-depth examinations of the most prevalent domains led to knowledge of gene expression changes between the free-living (egg, L1, L2 and L3 sheathed) and parasitic (L3 exsheathed, L4, and adult) stages. Domains previously implicated in growth and development such as chromo domains and the MADF domain tended to dominate in the free-living stages. In contrast, domains potentially involved in feeding such as the zinc finger and CAP domains dominated in the parasitic stages. Pathway analyses showed significant associations between life-cycle stages and peptides involved in energy metabolism in O. ostertagi whereas metabolism of cofactors and vitamins were specifically up-regulated in the parasitic stages of C. oncophora. Substantial differences were observed also between Gene Ontology terms associated with free-living and parasitic stages. This study characterized transcriptomes from multiple life stages from both C. oncophora and O. ostertagi. These data represent an important resource for studying these parasites. The results of this study show distinct differences in the genes involved in the free-living and parasitic life cycle stages. The data produced will enable better annotation of the upcoming genome sequences and will allow future comparative analyses of the biology, evolution and adaptation to parasitism in nematodes.
Capillary electrophoretic analysis of fragment length polymorphism in ribosomal markers of Cryptosporidium from humans
Publisher: Elsevier BV
Date: 12-2005
DOI: 10.1016/J.MCP.2005.07.001
Abstract: Cryptosporidium oocyst DNA s les (n=80) from humans with cryptosporidiosis in Australia and the UK were characterized genetically and categorized by capillary electrophoretic (CE) analysis of part of the small subunit gene (pSSU approximately 300bp) and second internal transcribed spacer (pITS-2 approximately 230bp) of nuclear ribosomal DNA. The licons were heat denatured and subjected to capillary electrophoresis in LPA matrix (Amersham) in a MegaBACEtrade mark 1000 system (Amersham). The chromatograms captured were stored electronically and then analysed using MegaBACEtrade mark Fragment Profiler software. Using reference DNA control s les representing Cryptosporidium hominis and Cryptosporidium parvum, particular peaks in the profiles were defined for their specific identification and differentiation. The two species could be readily differentiated based on their profile in the pSSU, the peak differences being associated with a nucleotide difference of <1.7%. While no variation was detectable in the pSSU profiles within each species, significant intraspecific variability in the positions of peaks in the pITS-2 chromatograms was displayed. For the 80 s les subjected to CE analysis of the pITS-2, four different genetic variants (genotypes) were detected within C. hominis and seven within C. parvum. Based on CE analysis of either pSSU and pITS-2 licons, it was readily possible to detect both species in 'mixed s les'. This CE method is time- and cost-effective, and may find applicability as a tool for the high throughput analysis of oocyst DNA s les for epidemiological surveys and for the monitoring of cryptosporidiosis outbreaks.
Application of multiple DNA fingerprinting techniques to study the genetic relationships among three members of the subgenus Trypanozoon (Protozoa: Trypanosomatidae)
Publisher: Elsevier BV
Date: 12-2005
DOI: 10.1016/J.MCP.2005.07.002
Abstract: Three different DNA fingerprinting techniques, the mobile genetic element (MGE)-PCR, simple sequence repeat (SSR)-PCR and random lified polymorphic DNA (RAPD)-PCR, were used to define a large set of genetic markers to study genetic similarity within and among Trypanosoma brucei, Trypanosoma equiperdum and Trypanosoma evansi strains (n=18) from China, Africa and South America and to investigate their genetic relationships. Using the three fingerprinting techniques, >890 bands (ranging in size from 0.2 to 2kb) were defined for all 18 strains of Trypanosoma. Within each of the strains, 39-59 bands were defined. The similarity coefficients between strains ranged from approximately 41 to 94%, with a mean of 65%. There was more genetic similarity among strains within T. evansi (mean of approximately 79%) compared with T. equiperdum ( approximately 65%) and T. brucei ( approximately 59%). The similarity coefficient data were used to construct the dendrogram, which revealed that (irrespective of species) the majority of strains from China and South America grouped together to the exclusion of those from Africa. The exceptions were a T. brucei strain from Africa and a T. equiperdum strain of unknown origin. Hence, employing data sets generated using the three different fingerprinting methods, it was not possible to unequivocally distinguish among T. brucei, T. evansi and T. equiperdum, although there was a tendency for T. evansi strains to group together to the exclusion of T. brucei. The findings provide support for the hypothesis that T. evansi originated from a mutated form of T. equiperdum and stimulate further investigations of the genetic make-up and evolution of members of the subgenus Trypanozoon.
Isolation of Giardia from Swiss cattle and cultivation of trophozoites in vitro
Publisher: Springer Science and Business Media LLC
Date: 1987
DOI: 10.1007/BF00536478
Abstract: Severe acute respiratory syndrome (SARS) is an emerging infectious disease caused by the novel coronavirus SARS-CoV. The T cell epitopes of the SARS CoV spike protein are well known, but no systematic evaluation of the functional and structural roles of each residue has been reported for these antigenic epitopes. Analysis of the functional importance of side-chains by mutational study may exaggerate the effect by imposing a structural disturbance or an unusual steric, electrostatic or hydrophobic interaction. We demonstrated that N50 could induce significant IFN-gamma response from SARS-CoV S DNA immunized mice splenocytes by the means of ELISA, ELISPOT and FACS. Moreover, S366-374 was predicted to be an optimal epitope by bioinformatics tools: ANN, SMM, ARB and BIMAS, and confirmed by IFN-gamma response induced by a series of S358-374-derived peptides. Furthermore, each of S366-374 was replaced by alanine (A), lysine (K) or aspartic acid (D), respectively. ANN was used to estimate the binding affinity of single S366-374 mutants to H-2 Kd. Y367 and L374 were predicated to possess the most important role in peptide binding. Additionally, these one residue mutated peptides were synthesized, and IFN-gamma production induced by G368, V369, A371, T372 and K373 mutated S366-374 were decreased obviously. We demonstrated that S366-374 is an optimal H-2 Kd CTL epitope in the SARS CoV S protein. Moreover, Y367, S370, and L374 are anchors in the epitope, while C366, G368, V369, A371, T372, and K373 may directly interact with TCR on the surface of CD8-T cells.
Barcoding of Giardia duodenalis isolates and derived lines from an established cryobank by a mutation scanning-based approach
Publisher: Wiley
Date: 08-2011
Cryptosporidium cuniculus - New records in human and kangaroo in Australia
Publisher: Springer Science and Business Media LLC
Date: 30-10-2014
Chromatographic and antigenic properties of Echinococcus granulosus hydatid cyst‐derived glycolipids
Publisher: Wiley
Date: 12-1993
DOI: 10.1111/J.1365-3024.1993.TB00582.X
Abstract: The neutral and acidic fraction glycolipids of Echinococcus granulosus metacestode tissue compartments were isolated, defined by their chromatographic and antigenic properties, and assessed as to their efficacy as antigens in the serodiagnosis of human hepatic cystic and alveolar echinococcosis, and other helminthiases. Analyses were accomplished by thin-layer chromatography immunostaining and ELISA. The neutral glycolipid fraction's major carbohydrate epitope was the same as or very similar to that of Taenia crassiceps neutral glyco(sphingo)lipids, as represented by the 'neogala'-series core structure. The blood group-active, carbohydrate epitope P1 was expressed by a number of neutral fraction glycolipid component bands. The reverse-phase, thin-layer chromatography-isolated neutral fraction glycolipid component, designated Ag1, was efficient in the serological discrimination of cystic echinococcosis medium to high-titred sera. Ag1 did not specifically discriminate low-titred sera, i.e., other human helminthiases. The detected sialic acid residues of the acidic fraction glycolipids, on enzymatic cleavage, were identified as N-acylneuraminic acid and terminal. The acidic fraction glycolipids exhibited the paradox of only chemically minor components being antigenic towards cystic and alveolar echinococcosis infection sera. The combined acidic fraction glycolipid components Ra and Rx were capable of serological discrimination between cystic echinococcosis, alveolar echinococcosis and other helminthiases.
Genetic richness and diversity in Cryptosporidium hominis and C. parvum reveals major knowledge gaps and a need for the application of “next generation” technologies — Research review
Publisher: Elsevier BV
Date: 2010
DOI: 10.1016/J.BIOTECHADV.2009.08.003
Abstract: Cryptosporidium species (apicomplexan protists) are a major cause of diarrhoeal disease (= cryptosporidiosis) in humans worldwide. The impact of cryptosporidiosis is also compounded by the spread of HIV/AIDS and a lack of cost-effective anti-cryptosporidial chemotherapeutics or vaccines. Mitigation of the impact of cryptosporidiosis in humans needs to focus on prevention and control strategies, built on a sound understanding of the epidemiology of Cryptosporidium species. Refined epidemiological studies rely on the use of molecular tools employing informative genetic markers. Currently, the 60-kDa glycoprotein gene (gp60) is the most suitable and widely used genetic marker for Cryptosporidium species infecting humans. Here, we undertake an analysis of all publicly-available gp60 sequence data and associated literature for C. hominis and C. parvum, and yield useful insights into the richness, ersity and distribution of genetic variants, and link these variants to human cryptosporidiosis. This global analysis reveals that, despite high genetic richness in Cryptosporidium isolates from humans, there is a surprisingly low ersity. It also highlights limited knowledge about the genetics of cryptosporidiosis in developing nations and in many animals that might act as infection sources. Clearly, there is a major need for more comprehensive studies of Cryptosporidium infecting humans and other animals in Africa and Asia. As molecular technologies improve and become affordable, future studies should utilize "next generation" sequencing and bioinformatic platforms to conduct comparative 'genome sequence surveys' to test the validity of current genetic classifications based on gp60 data. Complemented by in vitro and in vivo investigations, these biotechnological advances will also assist significantly in the search for new intervention strategies against human cryptosporidiosis.
Corrigendum to “Direct comparison of selected methods for genetic categorisation of Cryptosporidium parvum and Cryptosporidium hominis species” [International Journal for Parasitology 35 (2005) 397–41
Publisher: Elsevier BV
Date: 12-2005
Advances in the identification of Malassezia
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.MCP.2010.12.003
Abstract: Members of the genus Malassezia are lypophilic and/or lipid-dependent, unipolar budding yeasts that can become pathogenic under the influence of particular predisposing factors (e.g., changes in the cutaneous microenvironment and/or alterations in host defences). This genus comprises at least 14 species, which have been identified traditionally based on their morphology and biochemical features. However, phenetic characteristics often do not allow the identification or delineation of closely related Malassezia spp., such that molecular tools need to be used to assist in fundamental studies of the epidemiology and ecology of Malassezia as well as aspects of the pathogenesis and disease caused by members of this genus. This article briefly reviews the morphological and biochemical methods commonly used for the identification of Malassezia as well as DNA technological methods that have been established for the specific identification of members of this genus and the diagnosis of their infections. New avenues for the development of improved molecular-diagnostic methods to overcome diagnostic limitations and to underpin fundamental investigations of this interesting group of yeasts are proposed.
Polymerase chain reaction‐based differential diagnosis of Ancylostoma duodenale and Necator americanus infections in humans in northern Ghana
Publisher: Wiley
Date: 06-2005
DOI: 10.1111/J.1365-3156.2005.01440.X
Abstract: We evaluated a two-step semi-nested polymerase chain reaction (PCR)-based approach for the specific detection of Ancylostoma duodenale DNA in human faeces. The test was used to determine to what extent this species of hookworm is present in the regions of Bolgatanga and Garu of northern Ghana. Initially, the sensitivity and specificity of the PCR were tested using a range of well-defined control s les. Subsequently, a total of 378 human faecal DNA s les from Bolgatanga and Garu were subjected to the PCR. The results were compared with those obtained using a previously established PCR for the specific detection of Necator americanus DNA in human faeces. Infection with A. duodenale was recorded in 74 (19.6%) s les and N. americanus in 278 (73.5%), of which 64 (16.9%), represented co-infections with both species. While A. duodenale was predominantly detected in the s les from Bolgatanga, infections in Garu related almost exclusively to N. americanus. The results showed that the present PCR approach is a valuable complementary tool for the diagnosis of A. duodenale infection in humans in Ghana, having implications for epidemiological studies and for the monitoring of the success of control programmes in regions in Africa.
SBAL: a practical tool to generate and edit structure-based amino acid sequence alignments
Publisher: Oxford University Press (OUP)
Date: 12-02-2012
DOI: 10.1093/BIOINFORMATICS/BTS035
Abstract: Summary: Both alignment generation and visualization are important processes for producing biologically meaningful sequence alignments. Computational tools that combine reliable, automated and semi-automated approaches to produce secondary structure-based alignments with an appropriate visualization of the results are rare. We have developed SBAL, a tool to generate and edit secondary structure-based sequence alignments. It is easy to install and provides a user-friendly interface. Sequence alignments are displayed, with secondary structure assignments mapped to their corresponding regions in the sequence by using a simple colour scheme. The algorithm implemented for automated and semi-automated secondary structure-based alignment calculations shows a comparable performance to existing software. Availability and implementation: SBAL has been implemented in Java to provide cross-platform compatibility. SBAL is freely available to academic users at csb/. Users will be asked for their name, institution and email address. A manual can also be downloaded from this site. The software, manual and test sets are also available as supplementary material. Contact: conan.wang@griffith.edu.au Supplementary information: Supplementary data are available at Bioinformatics online.
Analysis of sequence homogenisation in rDNA arrays of Haemonchus contortus by denaturing gradient gel electrophoresis
Publisher: Wiley
Date: 10-1998
Abstract: Testing different theories of concerted evolution experimentally has been h ered mainly due to the lack of appropriate model systems and technical limitations. In this study, we employed a denaturing gradient gel electrophoresis (DGGE) approach for the display and definition of nucleotide variations in the second internal transcribed spacer (ITS-2) of ribosomal DNA (rDNA) of the parasitic nematode, Haemonchus contortus. The ITS-2 was lified from in idual adult nematodes by PCR and subjected to DGGE. Of the 94 in iduals (representing nine different populations) analysed, 13 different DGGE profiles were displayed. Eighteen bands representing those profiles were excised and sequenced. Sequencing defined 13 different types of ITS-2 with 12 nucleotide variations (4 transitions, 5 transversions, 1 insertion and 2 deletions) which could be related to particular positions of the predicted secondary structure for the ITS-2 pre-rRNA. The results showed that in iduals of interbreeding populations of H. contortus can have rDNA arrays that are partially or fully homogenised for different sequence variants (despite interin idual variation), suggesting that the homogenisation process is driven mainly by intrachromosomal exchange. The findings also demonstrated the capacity of the DGGE-sequencing strategy to quantify the frequency of ITS-2 sequence types within in idual nematodes from different populations without the need for cloning or Southern blot procedures. This has important implications for studying the mechanisms of sequence homogenisation in rDNA and pre-rRNA processing as well as for elucidating speciation events and population differentiation at the molecular level.
Extending from PARs inCaenorhabditis elegansto homologues inHaemonchus contortusand other parasitic nematodes
Publisher: Cambridge University Press (CUP)
Date: 16-11-2006
DOI: 10.1017/S0031182006001727
Abstract: Signal transduction molecules play key roles in the regulation of developmental processes, such as morphogenesis, organogenesis and cell differentiation in all organisms. They are organized into ‘pathways’ that represent a coordinated network of cell-surface receptors and intracellular molecules, being involved in sensing environmental stimuli and transducing signals to regulate or modulate cellular processes, such as gene expression and cytoskeletal dynamics. A particularly important group of molecules implicated in the regulation of the cytoskeleton for the establishment and maintenance of cell polarity is the PAR proteins (derived from par tition defective in asymmetric cell ision). The present article reviews salient aspects of PAR proteins involved in the early embryonic development and morphogenesis of the free-living nematode Caenorhabditis elegans and some other organisms, with an emphasis on the molecule PAR-1. Recent advances in the knowledge and understanding of PAR-1 homologues from the economically important parasitic nematode, Haemonchus contortus , of small ruminants is summarized and discussed in the context of exploring avenues for future research in this area for parasitic nematodes.
Molecular alterations during larval development of Haemonchus contortus in vitro are under tight post-transcriptional control
Publisher: Elsevier BV
Date: 08-2018
DOI: 10.1016/J.IJPARA.2018.03.008
Abstract: In this study, we explored the molecular alterations in the developmental switch from the L3 to the exsheathed L3 (xL3) and to the L4 stage of Haemonchus contortus in vitro using an integrated transcriptomic, proteomic and bioinformatic approach. Totals of 9,754 mRNAs, 88 microRNAs (miRNAs) and 1,591 proteins were identified, and 6,686 miRNA-mRNA pairs inferred in all larval stages studied. Approximately 16% of transcripts in the combined transcriptome (representing all three larval stages) were expressed as proteins, and there were positive correlations (r = 0.39-0.44) between mRNA transcription and protein expression in the three distinct developmental stages of the parasite. Of the predicted targets, 1,019 (27.0%) mRNA transcripts were expressed as proteins, and there was a negative correlation (r = -0.60 to -0.50) in the differential mRNA transcription and protein expression between developmental stages upon pairwise comparison. The changes in transcription (mRNA and miRNA) and protein expression from the free-living to the parasitic life cycle phase of H. contortus related to enrichments in biological pathways associated with metabolism (e.g., carbohydrate and lipid degradation, and amino acid metabolism), environmental information processing (e.g., signal transduction, signalling molecules and interactions) and/or genetic information processing (e.g., transcription and translation). Specifically, fatty acid degradation, steroid hormone biosynthesis and the Rap1 signalling pathway were suppressed, whereas transcription, translation and protein processing in the endoplasmic reticulum were upregulated during the transition from the free-living L3 to the parasitic xL3 and L4 stages of the nematode in vitro. Dominant post-transcriptional regulation was inferred to elicit these changes, and particular miRNAs (e.g., hco-miR-34 and hco-miR-252) appear to play roles in stress responses and/or environmental adaptations during developmental transitions of H. contortus. Taken together, these integrated results provide a comprehensive insight into the developmental biology of this important parasite at the molecular level in vitro. The approach applied here to H. contortus can be readily applied to other parasitic nematodes.
Comparison of the performance of three PCR assays for the detection and differentiation of Theileria orientalis genotypes
Publisher: Springer Science and Business Media LLC
Date: 31-03-2015
SOX9 Duplication Linked to Intersex in Deer
Publisher: Public Library of Science (PLoS)
Date: 06-09-2013
Next-Generation Molecular-Diagnostic Tools for Gastrointestinal Nematodes of Livestock, with an Emphasis on Small Ruminants
Publisher: Elsevier
Date: 2013
Global phylogeography and genetic diversity of the zoonotic tapeworm Echinococcus granulosus sensu stricto genotype G1.
Publisher: Elsevier BV
Date: 08-2018
Tv-RIO1 – an atypical protein kinase from the parasitic nematode Trichostrongylus vitrinus
Publisher: Springer Science and Business Media LLC
Date: 22-09-2008
Abstract: Protein kinases are key enzymes that regulate a wide range of cellular processes, including cell-cycle progression, transcription, DNA replication and metabolic functions. These enzymes catalyse the transfer of phosphates to serine, threonine and tyrosine residues, thus playing functional roles in reversible protein phosphorylation. There are two main groups, namely eukaryotic protein kinases (ePKs) and atypical protein kinases (aPKs) RIO kinases belong to the latter group. While there is some information about RIO kinases and their roles in animals, nothing is known about them in parasites. This is the first study to characterise a RIO1 kinase from any parasite. A full-length cDNA ( Tv-rio-1 ) encoding a RIO1 protein kinase ( Tv -RIO1) was isolated from the economically important parasitic nematode Trichostrongylus vitrinus (Order Strongylida). The uninterrupted open reading frame (ORF) of 1476 nucleotides encoded a protein of 491 amino acids, containing the characteristic RIO1 motif LVHADLSEYNTL. Tv-rio -1 was transcribed at the highest level in the third-stage larva (L3), and a higher level in adult females than in males. Comparison with homologues from other organisms showed that protein Tv -RIO1 had significant homology to related proteins from a range of metazoans and plants. Amino acid sequence identity was most pronounced in the ATP-binding motif, active site and metal binding loop. Phylogenetic analyses of selected amino acid sequence data revealed Tv -RIO1 to be most closely related to the proteins in the species of Caenorhabditis . A structural model of Tv -RIO1 was constructed and compared with the published crystal structure of RIO1 of Archaeoglobus fulgidus (Af -Rio1). This study provides the first insights into the RIO1 protein kinases of nematodes, and a foundation for further investigations into the biochemical and functional roles of this molecule in biological processes in parasitic nematodes.
First report of anthelmintic resistance in Haemonchus contortus in alpacas in Australia
Publisher: Springer Science and Business Media LLC
Date: 22-08-2013
The evolutionary origins of nematodes within the order Strongylida are related to predilection sites within hosts
Publisher: Elsevier BV
Date: 07-2006
DOI: 10.1016/J.YMPEV.2006.01.003
Abstract: The evolutionary relationships of the different groups of nematodes within the order Strongylida based on morphological data have been speculative and the subject of conjecture. In this paper, we present a multigene phylogenetic analysis, using sequence data of the 18S and 28S ribosomal RNA genes from representatives of all four suborders and seven superfamilies of the Strongylida, to test existing hypotheses proposed for the relationships of the suborders based on morphological data sets. The results obtained demonstrated that the Strongylida is a monophyletic assemblage, with only the Metastrongylina (but not the other suborders) forming a distinct monophyletic clade. We show that, in contrast to all previous hypotheses, one major lineage comprises taxa which occur exclusively in the pulmonary, circulatory or nervous systems of marsupial and eutherian mammals, whereas a second lineage comprises species occurring in the gastrointestinal tracts or perirenal tissues of vertebrates, or in the lungs of birds. The findings suggest that the predilection site of adult nematodes and host type reflect the evolutionary origin of the different taxonomic groups within the Strongylida.
Characterization of Oesophagostomum bifurcum and Necator americanus by PCR-RFLP of rDNA
Publisher: JSTOR
Date: 10-1997
DOI: 10.2307/3284301
The redlegged earth mite draft genome provides new insights into pesticide resistance evolution and demography in its invasive Australian range
Publisher: Wiley
Date: 27-12-2023
DOI: 10.1111/JEB.14144
Abstract: Genomic data provide valuable insights into pest management issues such as resistance evolution, historical patterns of pest invasions and ongoing population dynamics. We assembled the first reference genome for the redlegged earth mite, Halotydeus destructor (Tucker, 1925), to investigate adaptation to pesticide pressures and demography in its invasive Australian range using whole‐genome pool‐seq data from regionally distributed populations. Our reference genome comprises 132 autosomal contigs, with a total length of 48.90 Mb. We observed a large complex of ace genes, which has presumably evolved from a long history of organophosphate selection in H. destructor and may contribute towards organophosphate resistance through copy number variation, target‐site mutations and structural variants. In the putative ancestral H. destructor ace gene, we identified three target‐site mutations (G119S, A201S and F331Y) segregating in organophosphate‐resistant populations. Additionally, we identified two new para sodium channel gene mutations (L925I and F1020Y) that may contribute to pyrethroid resistance. Regional structuring observed in population genomic analyses indicates that gene flow in H. destructor does not homogenize populations across large geographic distances. However, our demographic analyses were equivocal on the magnitude of gene flow the short invasion history of H. destructor makes it difficult to distinguish scenarios of complete isolation vs. ongoing migration. Nonetheless, we identified clear signatures of reduced genetic ersity and smaller inferred effective population sizes in eastern vs. western populations, which is consistent with the stepping‐stone invasion pathway of this pest in Australia. These new insights will inform development of diagnostic genetic markers of resistance, further investigation into the multifaceted organophosphate resistance mechanism and predictive modelling of resistance evolution and spread.
The immunodiagnostic potential of Echinococcus granulosus adult-worm antigens in human cystic echinococcosis
Publisher: Springer Science and Business Media LLC
Date: 20-11-1996
Abstract: Echinococcus granulosus adult-worm antigens were characterised for assessment of their immunodiagnostic potential for human cystic echinococcosis (CE). The analysis of worm extracts by enzyme-linked immunosorbent assay (ELISA) showed a sensitivity of 83% for CE, which is comparable with data obtained for cyst-fluid-based serodiagnostic tests. Immunoprecipitation of in vitro-translated E. granulosus worm mRNA revealed a range of low-molecular-weight antigenic proteins (12-45 kDa) recognised by human CE sera. E. granulosus adult worms may provide an additional or alternative source to metacestode material for the isolation of both native and recombinant antigens to be considered for the serodiagnosis of human echinococcosis.
NEW HOST RECORD FOR THE ENTODINIOMORPHID CILIATE-TROGLODYTELLA ABRASSARTI, FROM SIAMANGS (HYLOBATES-SYNDACTYLUS)
Publisher: Elsevier BV
Date: 05-1993
DOI: 10.1016/0020-7519(93)90020-Y
Abstract: Examination of faecal s les from several diarrhoeic siamangs Hylobates syndactylus (Anthropoidea: Hylobatidae) revealed the presence of numerous entodiniomorphid ciliates whose morphological and ultrastructural characteristics were consistent with those of Troglodytella abrassarti previously recorded from chimpanzees, orangutans and gorillas (Anthropoidea: Pongidae).
A genome-wide analysis of annexins from parasitic organisms and their vectors
Publisher: Springer Science and Business Media LLC
Date: 11-10-2013
DOI: 10.1038/SREP02893
Influence of Evolutionary Allometry on Rates of Morphological Evolution and Disparity in strictly Subterranean Moles (Talpinae, Talpidae, Lipotyphla, Mammalia)
Publisher: Springer Science and Business Media LLC
Date: 06-01-2018
Unexpected occurrence of Haemonchus placei in cattle in southern Western Australia.
Publisher: Elsevier BV
Date: 2014
DOI: 10.1016/J.MEEGID.2013.10.025
Abstract: Haemonchus placei is an abomasal parasite of cattle, primarily in tropical and subtropical areas of the world. In Australia, this nematode can be extremely pathogenic in summer rainfall areas, particularly in the hot, sub-tropical Kimberley region, in the far north of the state of Western Australia (WA). Although cattle are occasionally transferred to southern parts of WA, it was believed that H. placei did not occur in southern regions of WA, as it is less cold-adapted than Haemonchus contortus, and the free-living stages would not develop during the cold winter and dry summer periods. Here, we show that, although H. contortus is found in cattle in the temperate southern region of WA, it appears that H. placei also occurs in southern WA. While investigating the prevalence of anthelmintic resistance in nematodes of cattle in WA, the existence of H. placei was suspected on a range of participating farms, following the morphological examination of third-stage larvae cultured from faeces, and of adult worms recovered from sheep experimentally infected with these larvae. Genomic DNAs from in idual worms as well as eggs from pooled faecal s les from seven farms in southern WA were subjected to PCR-based mutation scanning and sequence analyses of the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA. The results showed that both H. contortus and H. placei were harboured by cattle. This first record of H. placei in cattle in southern WA raises questions as to the prevalence and distribution of this parasite in other temperate and cool climatic regions of Australia. Although clinical disease due to H. placei has not yet been seen in southern WA, global, climatic trends might suggest an increased importance of this parasite in the longer term.
Complete mitochondrial genomes of the 'intermediate form' of Fasciola and Fasciola gigantica, and their comparison with F. hepatica
Publisher: Springer Science and Business Media LLC
Date: 31-03-2014
A theoretical study to establish the relationship between the three-dimensional structure of triose-phosphate isomerase of Giardia duodenalis and point mutations in the respective gene
Publisher: Elsevier BV
Date: 10-2010
DOI: 10.1016/J.MCP.2010.06.001
Abstract: Predicting how point mutations in genes alter the tertiary and quarternary structure of proteins is central to a number of areas of molecular biology and has implications in relation to the function and evolution of molecules. In the present study, we theoretically assessed the effects of 20 point mutations detected previously in a region of the triose-phosphate isomerase gene (tpi) of the protozoan Giardia duodenalis on the three-dimensional structure of the 'wild-type' protein (TPI). Amino acid substitutions arising from codon variations were mainly located at surface-accessible sites or in hydrophobic pockets of TPI. None of the substitutions was predicted to exert a significant change to the fold or functionality of the enzyme, with the exception of one alteration (Arg100). Almost all substitutions were either conservative or semi-conservative, and retained or even improved the expected stability of the fold. Overall, the findings provide support for the "neutral theory", which contends that evolution at the molecular level is not solely shaped by "Darwinian selection but also by random drift of selectively neutral or nearly neutral mutants".
Screening for different genotypes of Echinococcus granulosus within China and Argentina by single-strand conformation polymorphism (SSCP) analysis
Publisher: Oxford University Press (OUP)
Date: 05-1999
DOI: 10.1016/S0035-9203(99)90043-3
Abstract: Single-strand conformation polymorphism (SSCP) analysis was employed for the direct visual display of genetic variability in mitochondrial DNA (mtDNA) fragments within and among populations of Echinococcus granulosus from the People's Republic of China and from Argentina. Fragments of the NADH dehydrogenase I gene (NDI) and the cytochrome c oxidase subunit I (COI) were in idually lified from parasite DNA by polymerase chain reaction, denatured and subjected to SSCP analysis. Using NDI and COI fragments, s les representing different genotypes could be readily identified based on characteristic SSCP profiles. The results demonstrate the utility of SSCP for the direct visual display of nucleotide variation in mtDNA of E. granulosus prior to DNA sequence analysis. The approach compares favourably with existing genotyping procedures and provides a reliable and technically reproducible method for the routine laboratory identification of Echinococcus isolates.
Display of sequence variation in PCR-amplified mitochondrial DNA regions of Echinococcus by single-strand conformation polymorphism
Publisher: Elsevier BV
Date: 09-1998
DOI: 10.1016/S0001-706X(98)00052-7
Abstract: Echinococcosis, a disease caused by infection with the larval stage of a tapeworm parasite of the genus Echinococcus, is of major socio-economic importance, and studying genetic variability within and between Echinococcus populations has important implications for disease control and epidemiology. Various DNA approaches have been used to study Echinococcus genetics, but most methods do not allow the accurate display or definition of mutational/allelic variation. To overcome this limitation, we established a mutation scanning approach. Single-strand conformation polymorphism (SSCP) of two different enzymatically lified mitochondrial (mt) DNA regions was evaluated using seven different genotypes of Echinococcus (defined as G1, G4, G6, G8, O, V and M2). The NADH dehydrogenase 1 gene (ND1) or the cytochrome c oxidase subunit 1 (CO1) were lified by polymerase chain reaction from parasite DNA, denatured and directly subjected to electrophoresis in a non-denaturing gel matrix. Each of the seven genotypes examined could be delineated from one another based on characteristic and reproducible banding patterns. The results demonstrate the usefulness of SSCP for the direct visual display of sequence variation in mtDNA of Echinococcus without the need for DNA sequencing or restriction analyses, and indicate its potential for studying allelic variability in a range of other genes.
Screening of the 'Open Scaffolds' collection from Compounds Australia identifies a new chemical entity with anthelmintic activities against different developmental stages of the barber's pole worm and other parasitic nematodes.
Publisher: Elsevier BV
Date: 12-2017
Genetic classification of Echinococcus granulosus cysts from humans, cattle and camels in Libya using mutation scanning-based analysis of mitochondrial loci
Publisher: Elsevier BV
Date: 12-2010
DOI: 10.1016/J.MCP.2010.07.005
Abstract: We genetically classified Echinococcus granulosus from humans, cattle and camels in Libya utilizing DNA regions (designated pcox1 and pnad1) within the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase 1 (nad1) mitochondrial genes, respectively. Polymerase chain reaction (PCR)-based single-strand conformation polymorphism (SSCP) analysis of pcox1 and pnad1 licons derived from genomic DNA s les from in idual cysts (n = 176) revealed four distinct electrophoretic profiles for each locus. Direct sequencing of selected licons representing each of these profiles defined four different sequence types for each locus, which were present in five different combinations (designated haplotypes A-E) amongst all 176 isolates. Phylogenetic analysis of concatenated sequence data for these five haplotypes, together with a range of well-defined reference sequences, inferred that all cyst isolates from humans (n = 55) and a small number from cattle (13% of 38) belonged to the G1-G3 complex of E. granulosus (or E. granulosus sensu stricto), whereas most (87%) cysts from cattle and all 83 of them from camels were linked to the G6-G10 complex (or Echinococcus canadensis). The present study provides a foundation for future large-scale studies of the epidemiology and ecology of E. granulosus in Libya and other African countries.
Molecular tools—advances, opportunities and prospects
Publisher: Elsevier BV
Date: 03-2006
DOI: 10.1016/J.VETPAR.2005.12.002
Abstract: Modern molecular technologies are having a substantial impact in many fundamental and applied areas of parasitology. In particular, polymerase chain reaction (PCR)-coupled approaches have found broad applicability because their sensitivity permits the enzymatic lification of gene fragments from minute quantities of nucleic acids from tiny amounts of parasite material. Also, high-resolution electrophoretic and genomic methods are finding increased utility. This paper briefly discusses some developments and applications of DNA methods to parasites and highlights their usefulness or potential for those of veterinary importance. Selected ex les of applications with implications in fundamental (systematics, population genetics, epidemiology and ecology) and applied (diagnosis, prevention and control) areas are presented. The focus is mainly on tools for the accurate identification of parasitic nematodes and protozoa of socio-economic importance, the diagnosis of infections and the detection of genetic variability using PCR-coupled mutation scanning technology.
Molecular delineation of Cylicocyclus nassatus and C. ashworthi (Nematoda: Strongylidae)
Publisher: Elsevier BV
Date: 05-1997
DOI: 10.1016/S0020-7519(96)00192-0
Abstract: The nucleotide sequences of the first internal transcribed spacer (ITS-1), 5.8S gene and second internal transcribed spacer (ITS-2) of ribosomal DNA have been determined for Cylicocyclus nassatus, C. ashworthi and C. insignis. Pairwise comparisons revealed sequence differences between the taxa ranging from 3.8 to 6.2% for the ITS-2 and 2.2-2.7% for the ITS-1. For the ITS-1, the level of the sequence difference between C. ashworthi and C. nassatus (2.2%) was equivalent to that between C. nassatus and C. insignis (2.2%), indicating that C. ashworthi and C. nassatus represent separate species. Theoretical restriction maps were constructed from the sequence data, and a polymerase chain reaction-linked restriction fragment length polymorphism (PCR-linked RFLP) technique was established to unequivocally distinguish C. ashworthi from C. nassatus.
First record of a tandem-repeat region within the mitochondrial genome of clonorchis sinensis using a long-read sequencing approach
Publisher: Public Library of Science (PLoS)
Date: 26-08-2020
Comparative analysis of mitochondrial genome data for Necator americanus from two endemic regions reveals substantial genetic variation
Publisher: Elsevier BV
Date: 08-2003
DOI: 10.1016/S0020-7519(03)00129-2
Abstract: Necator americanus is a blood-sucking, intestinal nematode of major human health importance in many tropical and subtropical regions of the world. The aim of the present study was to compare the complete mitochondrial genome sequence from one N. americanus in idual from Togo with another from China, in order to estimate the magnitude of genetic variability for different mitochondrial genes and non-coding regions. For the 12 protein genes, this comparison revealed sequence differences at both the nucleotide (3-7%) and amino acid (1-7%) levels. The most conserved of these was the nad4L gene, whereas the nad1 gene was least conserved at both the nucleotide and amino acid levels. Nucleotide differences were also detected in 14 of the 22 transfer RNAs (trns) (1-13%), the AT-rich region ( approximately 8%), non-coding regions (8-25%) and in the small (rrnS) and large (rrnL) subunits of mitochondrial ribosomal RNA (rrn) ( approximately 1%). Comparison of the rrnL sequences among multiple in idual worms revealed nine unequivocal nucleotide differences between N. americanus from the two countries. Consistent with previous studies, these findings provide evidence for substantial genetic variation within N. americanus, which may have implications for the transmission and control of hookworm disease.
PCR-SSCP of rDNA for the identification ofTrichinellaisolates from mainland China
Publisher: Elsevier BV
Date: 02-1998
Abstract: A polymerase chain reaction (PCR)-based single strand conformation polymorphism (SSCP) analysis of the expansion segment 5 (domain IV) of the large subunit of ribosomal DNA was employed to characterize seven isolates of Trichinella from China (A-G), including six of pig origin from regions in Dengxian (A), Tianjin (B), Harbin (D), Baoshan (E), Xinye (F) and Xian (G), and one of canine origin from Changchun (C). Isolates A, D, E, F and G were classified as Trichinella spiralis based on SSCP patterns, while the patterns for isolates B and C were consistent with those of Trichinella nativa or Trichinella T6. The results were supported by random lified polymorphic DNA (RAPD) analysis using five decamer primers and were in accordance with ecological information for the isolates. Single strand conformation polymorphism results also allowed the direct display of mutational sequence variation in the expansion segment among the five isolates of T. spiralis from China, indicating its usefulness for studying population variation within that species.
Discovery of acrylonitrile-based small molecules active against Haemonchus contortus
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3MD00255A
Molecular-based investigation of Cryptosporidium and Giardia from animals in water catchments in southeastern Australia.
Publisher: Elsevier BV
Date: 04-2013
DOI: 10.1016/J.WATRES.2012.12.027
Abstract: There has been no large-scale systematic molecular epidemiological investigation of the waterborne protozoans, Cryptosporidium or Giardia, in southeastern Australia. Here, we explored, for the first time, the genetic composition of these genera in faecal s les from animals in nine Melbourne Water reservoir areas, collected over a period of two-years. We employed PCR-based single-strand conformation polymorphism (SSCP) and phylogenetic analyses of loci (pSSU and pgp60) in the small subunit (SSU) of ribosomal RNA and 60-kDa glycoprotein (gp60) genes to detect and characterise Cryptosporidium, and another locus (ptpi) in the triose-phosphate isomerase (tpi) gene to identify and characterise Giardia. Cryptosporidium was detected in 2.8% of the 2009 s les examined the analysis of all licons defined 14 distinct sequence types for each of pSSU and pgp60, representing Cryptosporidium hominis (genotype Ib - subgenotype IbA10G2R2), Cryptosporidium parvum (genotype IIa - subgenotypes IIaA15G2R1, IIaA19G2R1, IIaA19G3R1, IIaA19G4R1, IIaA20G3R1, IIaA20G4R1, IIaA20G3R2 and IIaA21G3R1), Cryptosporidium cuniculus (genotype Vb - subgenotypes VbA22R4, VbA23R3, VbA24R3, VbA25R4 and VbA26R4), and Cryptosporidium canis, Cryptosporidium fayeri, Cryptosporidium macropodum and Cryptosporidium ubiquitum as well as six new pSSU sequence types. In addition, Giardia was identified in 3.4% of the s les all 28 distinct ptpi sequence types defined were linked to assemblage A of Giardia duodenalis. Of all 56 sequence types characterised, eight and one have been recorded previously in Cryptosporidium and Giardia, respectively, from humans. In contrast, nothing is known about the zoonotic potential of 35 new genotypes of Cryptosporidium and Giardia recorded here for the first time. Future work aims to focus on estimating the prevalence of Cryptosporidium and Giardia genotypes in humans and a wide range of animals in Victoria and elsewhere in Australia. (Nucleotide sequences reported in this paper are available in the GenBank database under accession nos. KC282952-KC283005).
Insights into the epidemiology and genetic make-up ofOesophagostomum bifurcumfrom human and non-human primates using molecular tools
Publisher: Cambridge University Press (CUP)
Date: 07-12-2005
DOI: 10.1017/S0031182005009406
Abstract: The nodule worm Oesophagostomum bifurcum (Nematoda: Strongylida) is a parasite of major human health importance predominantly in northern Togo and Ghana. Currently, it is estimated that 0·25 million people are infected with this nematode, and at least 1 million people are at risk of infection. Infection with this parasite causes significant disease as a consequence of encysted larvae in the wall of the large intestine. In spite of the health problems caused by O. bifurcum , there have been significant gaps in the knowledge of the biology, transmission and population genetics of the parasite. This review provides an account of some recent insights into the epidemiology and genetics of the parasite from human and non-human primate hosts in specific regions of Africa using molecular tools. Recent research findings are discussed mainly in relation to non-human primates being reservoirs of infection, and the consequences for the prevention and control of oesophagostomiasis in humans are briefly discussed.
Novel 1-Methyl-1H-pyrazole-5-carboxamide Derivatives with Potent Anthelmintic Activity
Publisher: American Chemical Society (ACS)
Date: 15-03-2019
DOI: 10.1021/ACS.JMEDCHEM.8B01790
Abstract: A phenotypic screen of two different libraries of small molecules against the motility and development of the parasitic nematode Haemonchus contortus led to the identification of two 1-methyl-1 H-pyrazole-5-carboxamide derivatives. Medicinal chemistry optimization targeted modifications of the left-hand side, middle section, and right-hand side of the hybrid structure of these two hits to elucidate the structure-activity relationship (SAR). Initial SAR around these hits allowed for the iterative and directed assembly of a focused set of 30 analogues of their hybrid structure. Compounds 10, 17, 20, and 22 were identified as the most potent compounds, inhibiting the development of the fourth larval (L4) stage of H. contortus at sub-nanomolar potencies while displaying strong selectivity toward the parasite when tested in vitro against the human MCF10A cell line. In addition, compounds 9 and 27 showed promising activity against a panel of other parasitic nematodes, including hookworms and whipworms.
Analysis of the genetic diversity within Cryptosporidium hominis and Cryptosporidium parvum from imported and autochtonous cases of human cryptosporidiosis by mutation scanning
Publisher: Wiley
Date: 11-2008
Abstract: The present study investigated sequence variation in part of the 60 kilodalton glycoprotein (pgp60) gene among Cryptosporidium hominis and Cryptosporidium parvum isolates (n=115) from citizens of the UK inferred to have been infected whilst travelling abroad (to 25 countries) or in the UK. The genomic DNA s les from these isolates were subjected to PCR-coupled single-strand conformation polymorphism analysis, followed by targeted sequencing of pgp60. In idual s les were classified to the genotypic and subgenotypic levels based on phylogenetic analysis (Bayesian inference) of pgp60 data, including published sequences for comparison. Based on this analysis, five C. hominis (Ia-If) and four C. parvum (IIa, IIc-IIe) genotypes were identified, equating to 16 and 10 subgenotypes, respectively. Of these genotypes, C. hominis Ib was predominant (n=82). Interestingly, one subgenotype (C. hominis Ib A10G2R2) accounted for the majority of the s les examined and was identified in travellers to 14 countries the examination of published records suggested that C. hominis Ib A10G2R2 has a global distribution. Numerous new and seemingly rare subgenotypes (eight for C. hominis and six for C. parvum) were also discovered. In conclusion, the present study revealed substantial genetic variation in pgp60 within both C. hominis and C. parvum and emphasizes the need to undertake investigations of human and animal populations in countries for which there is no information on the genetic make-up of Cryptosporidium infecting humans.
Specific fingerprinting of nematodes by PCR with single primers to defined repetitive elements
Publisher: Elsevier BV
Date: 10-1995
DOI: 10.1016/0001-706X(95)00108-Q
Abstract: We report a 50-year-old man with celiac disease who presented with occipital epilepsy. Brain MRI showed right occipital subcortical white matter hyperintensities, consistent with the posterior epileptic focus suggested by the clinical features of the seizures and documented on EEG. Shortly after the introduction of a gluten-free diet, the white matter abnormalities resolved. The patient went on to develop simultagnosia. Follow-up MRI showed right occipital lobe atrophy. This report emphasizes the importance of recognizing gluten-associated neurologic manifestations and usefulness of thegluten-free diet.
Toxocara eggs in public places worldwide - A systematic review and meta-analysis
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.ENVPOL.2018.07.087
Abstract: Toxocariasis is a neglected tropical disease of humans. Although many studies have indicated or shown that environmental contamination with Toxocara species eggs is a major risk factor for toxocariasis in humans, there has been no comprehensive analysis of published data or information. Here, we conducted the first systematic review and meta-analysis of current literature to assess the global prevalence of Toxocara eggs in public places (including beaches, parks and playgrounds). We conducted searches of the PubMed, Embase, Scopus and Science Direct databases for relevant studies published until 20 April 2018, and assessed the prevalence rates of Toxocara eggs in public places. We used the random effects model to calculate pooled prevalence estimates, with 95% confidence intervals (CIs), and analysed data in relation to WHO geographical regions. Subgroup analysis and meta-regressions regarding the geographical and environmental variables were also performed. Of 2384 publications identified, 109 studies that tested 42,797 soil s les in 40 countries were included in the meta-analysis. The pooled global prevalence of Toxocara eggs in public places was 21% (95% CI, 16-27% 13,895/42,797). The estimated prevalence rates in the different WHO regions ranged from 13% to 35%: Western Pacific (35% 95% CI, 15-58%), Africa (27% 95% CI, 11-47%), South America (25% 95% CI, 13-33%), South-East Asia (21% 95% CI, 3-49%), Middle East and North Africa (18% 95% CI, 11-24%), Europe (18% 95% CI, 14-22%), and North and Central Americas (13% 95% CI, 8-23%). A high prevalence was significantly associated with high geographical longitude (P = 0.04), low latitude (P = 0.02) and high relative environmental humidity (P = 0.04). This meta-analysis of data from published records indicates that public places are often heavily contaminated with eggs of Toxocara. This finding calls for measures to reduce the potential risk of infection and disease in humans.
Tick-borne diseases of bovines in Pakistan: major scope for future research and improved control
Publisher: Springer Science and Business Media LLC
Date: 22-05-2015
The developmental lipidome of Haemonchus contortus
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.IJPARA.2018.06.002
Abstract: Lipids play crucial roles in the biology of organisms, particularly relating to cellular membranes, energy storage, and intra- or inter-cellular signalling. Despite the recent expansion of the lipidomics field, very little is known about the biology of lipids in metzoan pathogens, and, to date, there has been no global lipidomic study of a parasitic nematode. Using Haemonchus contortus (barber's pole worm) as a model, we describe the first known global lipidome for a parasitic nematode via high throughput LC-MS/MS-based lipidomics. We identified a total of 554 lipid species across four lipid categories, and 18 lipid classes exhibited alterations among six developmental stages (eggs L3 and exsheathed L3 (xL3) and L4 larval stages female and male adults) of H. contortus. The lipid composition and abundance of H. contortus changed significantly during the transition from free-living (egg, L3 and xL3) to parasitic (L4 and adult) stages. The three main changes observed were: (i) decreased synthesis of triradylglycerols (ii) increased glycerophospholipids (predominantly glycerophosphoethanolamines and glycerophosphocholines) and (iii) a 'cooperative' modulation of ether-linked lipids and saturated fatty acids. These changes suggest specific adaptations, in terms of nutrient acquisition, metabolism and development, as the nematode makes its transition to the parasitic stage inside the host animal. This lipidomic data set serves as a stimulus for studies to understand lipid biology in parasitic worms, and their roles in parasite-host interactions and disease processes.
High-quality Schistosoma haematobium genome achieved by single-molecule and long-range sequencing
Publisher: Oxford University Press (OUP)
Date: 09-2019
DOI: 10.1093/GIGASCIENCE/GIZ108
Abstract: Schistosoma haematobium causes urogenital schistosomiasis, a neglected tropical disease affecting million people worldwide. Chronic infection with this parasitic trematode can lead to urogenital conditions including female genital schistosomiasis and bladder cancer. At the molecular level, little is known about this blood fluke and the pathogenesis of the disease that it causes. To support molecular studies of this carcinogenic worm, we reported a draft genome for S. haematobium in 2012. Although a useful resource, its utility has been somewhat limited by its fragmentation. Here, we systematically enhanced the draft genome of S. haematobium using a single-molecule and long-range DNA-sequencing approach. We achieved a major improvement in the accuracy and contiguity of the genome assembly, making it superior or comparable to assemblies for other schistosome species. We transferred curated gene models to this assembly and, using enhanced gene annotation pipelines, inferred a gene set with as many or more complete gene models as those of other well-studied schistosomes. Using conserved, single-copy orthologs, we assessed the phylogenetic position of S. haematobium in relation to other parasitic flatworms for which draft genomes were available. We report a substantially enhanced genomic resource that represents a solid foundation for molecular research on S. haematobium and is poised to better underpin population and functional genomic investigations and to accelerate the search for new disease interventions.
Echinococcus granulosus myophilin—Relationship with protein homologues containing “Calponinmotifs”
Publisher: Elsevier BV
Date: 12-1997
DOI: 10.1016/S0020-7519(97)00146-X
Abstract: Myophilin, a smooth-muscle protein of the tapeworm Echinococcus granulosus, was recently postulated to be a member of the calponin family of proteins. A detailed genetic analysis revealed that 17 proteins had significant homology with the amino-acid sequence of the N-terminal region of myophilin and/or possessed one or more "calponin-motifs". Comparison of the amino-acid sequences of the N-terminus showed that the homologous proteins clustered into distinct groups based on the number of calponin-motifs. The calponin-motif of myophilin was genetically more similar to that present in the muscle protein mp20 of Drosophila melanogaster than to those in any other homologous proteins of vertebrates. The existence of a distinct motif which is "conserved" in other proteins across a range of species suggests an important functional role for the motif.
The mitochondrial genomes of Ancylostoma caninum and Bunostomum phlebotomum – two hookworms of animal health and zoonotic importance
Publisher: Springer Science and Business Media LLC
Date: 11-02-2009
Abstract: Hookworms are blood-feeding nematodes that parasitize the small intestines of many mammals, including humans and cattle. These nematodes are of major socioeconomic importance and cause disease, mainly as a consequence of anaemia (particularly in children or young animals), resulting in impaired development and sometimes deaths. Studying genetic variability within and among hookworm populations is central to addressing epidemiological and ecological questions, thus assisting in the control of hookworm disease. Mitochondrial (mt) genes are known to provide useful population markers for hookworms, but mt genome sequence data are scant. The present study characterizes the complete mt genomes of two species of hookworm, Ancylostoma caninum (from dogs) and Bunostomum phlebotomum (from cattle), each sequenced (by 454 technology or primer-walking), following long-PCR lification from genomic DNA (~20–40 ng) isolated from in idual adult worms. These mt genomes were 13717 bp and 13790 bp in size, respectively, and each contained 12 protein coding, 22 transfer RNA and 2 ribosomal RNA genes, typical for other secernentean nematodes. In addition, phylogenetic analysis (by Bayesian inference and maximum likelihood) of concatenated mt protein sequence data sets for 12 nematodes (including Ancylostoma caninum and Bunostomum phlebotomum ), representing the Ascaridida, Spirurida and Strongylida, was conducted. The analysis yielded maximum statistical support for the formation of monophyletic clades for each recognized nematode order assessed, except for the Rhabditida. The mt genomes characterized herein represent a rich source of population genetic markers for epidemiological and ecological studies. The strong statistical support for the construction of phylogenetic clades and consistency between the two different tree-building methods employed indicate the value of using whole mt genome data sets for systematic studies of nematodes. The grouping of the Spirurida and Ascaridida to the exclusion of the Strongylida was not supported in the present analysis, a finding which conflicts with the current evolutionary hypothesis for the Nematoda based on nuclear ribosomal gene data.
Diversity in parasitic helminths of Australasian marsupials and monotremes: a molecular perspective.
Publisher: Elsevier BV
Date: 10-2014
DOI: 10.1016/J.IJPARA.2014.06.001
Abstract: Marsupials and monotremes are a prominent part of the mammalian fauna in Australia, and harbour an extremely erse and highly distinctive array of helminth parasites. Their study has been relatively neglected, likely because they have no direct, adverse socioeconomic impact. As the body plans of helminths generally are very simple and morphological characterisation likely underestimates true ersity, molecular tools have been employed to assess genetic ersity. Using biochemical and/or molecular methods, recent studies show extensive ersity in helminths of marsupials, with cryptic species being commonly encountered. The purpose of this article is to review current knowledge about the ersity of parasitic helminths of marsupials and monotremes, to raise questions as to whether current molecular data can be used to estimate ersity, what mechanisms lead to such ersity, to critically appraise the molecular tools that have been employed thus far to explore ersity and to discuss the directions which might be taken in the future employing improved techniques.
Unlocking the Transcriptomes of Two Carcinogenic Parasites, Clonorchis sinensis and Opisthorchis viverrini
Publisher: Public Library of Science (PLoS)
Date: 22-06-2010
Genomics of reproduction in nematodes: prospects for parasite intervention?
Publisher: Elsevier BV
Date: 02-2008
Abstract: Understanding reproductive processes in parasitic nematodes has the potential to lead to the informed design of new anthelmintics and control strategies. Little is known, however, about the molecular mechanisms underlying sex determination, gametogenesis and reproductive physiology for most parasitic nematodes. Together with comparative analyses of data for the free-living nematode Caenorhabditis elegans, molecular investigations are beginning to provide insights into the processes involved in reproduction and development in parasitic nematodes. Here, we review recent developments, focusing on technological aspects and on molecules associated with sex-specific differences in adult nematodes.
Proteomics elucidates key molecules involved in exsheathment in vitro in Oesophagostomum dentatum
Publisher: Elsevier BV
Date: 10-2014
Phylogenetic relationships of australian strongyloid nematodes inferred from ribosomal DNA sequence data
Publisher: Elsevier BV
Date: 12-1997
DOI: 10.1016/S0020-7519(97)00134-3
Abstract: The sequence of the second internal transcribed spacer of the ribosomal DNA was determined for the following strongyloid nematodes: Cylicocyclus insignis, Chabertia ovina, Oesophagostomum venulosum, Cloacina communis, Cloacina hydriformis, Labiostrongylus labiostrongylus, Parazoniolaimus collaris, Macropostrongylus macropostrongylus, Macropostrongylus yorkei, Rugopharynx australis, Rugopharynx rosemariae, Macropostrongyloides baylisi, Oesophagostomoides longispicularis and Paramacropostrongylus toraliformis, and compared with published sequences for species of Strongylus and for Hypodontus macropi. The resultant phylogenetic trees supported current hypotheses based on morphological evidence for the separation of the families Strongylidae and Chabertiidae, but did not support the separation of the endemic Australian genera as a distinctive clade within the Chabertiidae. The implications of this finding for the phylogenetic origins of the Australian strongyloids are discussed.
A TGF-β type I receptor-like molecule with a key functional role in Haemonchus contortus development
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.IJPARA.2018.06.005
Abstract: Here we investigated the gene of a transforming growth factor (TGF)-β type I receptor-like molecule in Haemonchus contortus, a highly pathogenic and economically important parasitic nematode of small ruminants. Designated Hc-tgfbr1, this gene is transcribed in all developmental stages of H. contortus, and the encoded protein has glycine-serine rich and kinase domains characteristic of a TGF-β family type I receptor. Expression of a GFP reporter driven by the putative Hc-tgfbr1 promoter localised to two intestinal rings, the anterior-most intestinal ring (int ring I) and the posterior-most intestinal ring (int ring IX) in Caenorhabditis elegans in vivo. Heterologous genetic complementation using a plasmid construct containing Hc-tgfbr1 genomic DNA failed to rescue the function of Ce-daf-1 (a known TGF-β type I receptor gene) in a daf-1-deficient mutant strain of C. elegans. In addition, a TGF-β type I receptor inhibitor, galunisertib, and double-stranded RNA interference (RNAi) were employed to assess the function of Hc-tgfbr1 in the transition from exsheathed L3 (xL3) to the L4 of H. contortus in vitro, revealing that both galunisertib and Hc-tgfbr1-specific double-stranded RNA could retard L4 development. Taken together, these results provide evidence that Hc-tgfbr1 is involved in developmental processes in H. contortus in the transition from the free-living to the parasitic stage.
First detection and genetic characterisation of Enterocytozoon bieneusi in wild deer in Melbourne's water catchments in Australia.
Publisher: Springer Science and Business Media LLC
Date: 03-01-2018
Bioinformatic exploration of RIO protein kinases of parasitic and free-living nematodes
Publisher: Elsevier BV
Date: 10-2014
DOI: 10.1016/J.IJPARA.2014.06.005
Abstract: Despite right open reading frame kinases (RIOKs) being essential for life, their functions, substrates and cellular pathways remain enigmatic. In the present study, gene structures were characterised for 26 RIOKs from draft genomes of parasitic and free-living nematodes. RNA-seq transcription profiles of riok genes were investigated for selected parasitic nematodes and showed that these kinases are transcribed in developmental stages that infect their mammalian host. Three-dimensional structural models of Caenorhabditis elegans RIOKs were predicted, and elucidated functional domains and conserved regions in nematode homologs. These findings provide prospects for functional studies of riok genes in C. elegans, and an opportunity for the design and validation of nematode-specific inhibitors of these enzymes in socioeconomic parasitic worms.
Genetic categorization of Echinococcus granulosus from humans and herbivorous hosts in Iran using an integrated mutation scanning-phylogenetic approach
Publisher: Wiley
Date: 08-2009
Abstract: In the present study, we have extended earlier taxonomic, biochemical and experimental investigations to characterize Echinococcus granulosus from various hosts in Iran utilizing DNA regions (designated pcox1 and pnad1) within the cytochrome c oxidase subunit 1 and NADH dehydrogenase 1 mitochondrial genes, respectively. An emphasis was placed on the characterization of E. granulosus isolates (cyst material) from humans, sheep, goats, cattle and camels, and on assessing their genetic relationships. PCR-based SSCP analysis of pcox1 and pnad1 licons derived from in idual isolates (n=148) of E. granulosus revealed five (pc1-pc5) and nine (pn1-pn9) electrophoretic profiles, respectively. Sequencing of pcox1 and pnad1 licons representing unique SSCP profiles demonstrated that each profile was linked unequivocally to a particular sequence and that single point mutations were readily detectable by SSCP. Phylogenetic analyses of pcox1 and/or pnad1 nucleotide sequence data were conducted using Bayesian inference and maximum likelihood tree-building methods. Following the phylogenetic analyses of concatenated pcox1+pnad1 sequence data, including representatives of all presently recognized Echinococcus species/genotypes as well as Taenia saginata (as the outgroup), the majority of cyst isolates (142 of 148 95.9%) from humans, ruminants (sheep, goats and cattle) and camels were assigned to the G1-G3 complex of E. granulosus (or E. granulosus sensu stricto), whereas some E. granulosus cysts (6 of 19 31.6%) from camels were assigned to the G6-G10 complex (or E. canadensis). The present study reinforces the advantages of the mutation scanning-sequencing-phylogenetic approach to explore variation in multiple mitochondrial loci within and among Echinococcus populations, which provides a platform for future, detailed studies of the molecular epidemiology of E. granulosus in Iran and other countries. (Note: The sequences determined in the present study have been deposited in the GenBank database under accession numbers: FJ796203-FJ796207 (pcox1) and FJ796208-FJ796216 (pnad1)).
Parasite transmission by insects: a female affair?
Publisher: Elsevier BV
Date: 03-2008
Abstract: Understanding the relationship between the gender of insects and their ability to act as vectors of insect-borne diseases (IBDs) could provide clues as to the origin of the intimate interplay among insect, pathogen and vertebrate hosts. The vector activity of several species of blood-feeding insects is linked to adult females. Interestingly, the only known exception is the transmission of canine and human thelaziosis by a male dipteran fly. This biological difference raises the question as to whether the parasitic behaviour of male and female insects transmitting IBDs is an expression of a co-evolution of vectors and pathogens.
Genomics of worms, with an emphasis on Opisthorchis viverrini — opportunities for fundamental discovery and biomedical outcomes
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.PARINT.2016.01.005
Abstract: Neglected tropical diseases cause substantial morbidity and mortality in animals and people globally. Opisthorchiasis is one such disease, caused by the carcinogenic, Asian liver fluke, Opisthorchis viverrini. This hepatobiliary disease is known to be associated with malignant cancer (cholangiocarcinoma, CCA) and affects millions of people in Asia, including Thailand, Lao People's Democratic Republic (PDR) and Cambodia. No vaccine is available, and only one drug (praziquantel) is routinely employed against the parasite. Relatively little is known about the molecular biology of the fluke itself and the disease complex that it causes in humans. With the advent of high-throughput nucleic acid sequencing and bioinformatic technologies, it has now become possible to gain global insights into the molecular biology of parasites. The purpose of this minireview is (i) to discuss recent progress on the genomics of parasitic worms, with an emphasis on the draft genome and transcriptome of O. viverrini (ii) to use results from an integrated, global analysis of the genomic and transcriptomic data, to explain how we believe that this carcinogenic fluke establishes in the biliary system, how it feeds, survives and protects itself in such a hostile, microaerobic environment within the liver, and to propose how this parasite evades or modulates host attack and (iii) to indicate some of the challenges, and, more importantly, the exciting opportunities that the 'omic resources for O. viverrini now provide for a plethora of fundamental and applied research areas. Looking ahead, we hope that this genomic resource stimulates vibrant and productive collaborations within a consortium context, focused on the effective control of opisthorchiasis.
Decoding the Ascaris suum Genome using Massively Parallel Sequencing and Advanced Bioinformatic Methods – Unprecedented Prospects for Fundamental and Applied Research
Publisher: Elsevier
Date: 2013
Epidemiological survey following oriental theileriosis outbreaks in Victoria, Australia, on selected cattle farms
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.VETPAR.2013.06.023
Abstract: This study investigated Theileria orientalis following outbreaks of oriental theileriosis in cattle in the state of Victoria, Australia, from September 2010 to January 2012, using traditional and molecular methods of diagnosis. A questionnaire was used to collect epidemiological information from cattle farms. Blood s les (n=301), collected from in idual symptomatic and asymptomatic cattle from 19 cattle farms, were examined for the presence of Theileria on stained blood smears and tested using a PCR-based approach, employing a region within the major piroplasm surface protein (MPSP) gene as a marker. The microscopic examination of stained blood smears detected stages consistent with Theileria piroplasms in 28.1% (79/281) of the s les. PCR products were lified from 70.8% (213/301) of the s les. Mutation scanning analysis of all licons displayed seven distinct profiles. Following the direct sequencing of representative licons, the genotypes ikeda, chitose, buffeli and type 5 were detected in 91.1%, 32.9%, 2.4% and 1.4% of 213 blood s les, respectively. The distribution of these four genotypes varied among the 19 farms genotype ikeda was detected on all farms, whereas genotypes chitose, buffeli and type 5 were detected on 14, 3 and 2 farms, respectively. Mix infections with genotypes ikeda and chitose were common (21.6%). Survey results revealed that oriental theileriosis affected mainly beef cows of more than two years of age, prior to calving, and disease was associated with abortion and cow deaths. Future investigations should focus on developing improved tools for investigating and managing oriental theileriosis.
First Evidence of Function for Schistosoma japonicumriok-1 and RIOK-1
Publisher: MDPI AG
Date: 08-07-2021
DOI: 10.3390/PATHOGENS10070862
Abstract: Protein kinases are known as key molecules that regulate many biological processes in animals. The right open reading frame protein kinase (riok) genes are known to be essential regulators in model organisms such as the free-living nematode Caenorhabditis elegans. However, very little is known about their function in parasitic trematodes (flukes). In the present study, we characterized the riok-1 gene (Sj-riok-1) and the inferred protein (Sj-RIOK-1) in the parasitic blood fluke, Schistosoma japonicum. We gained a first insight into function of this gene rotein through double-stranded RNA interference (RNAi) and chemical inhibition. RNAi significantly reduced Sj-riok-1 transcription in both female and male worms compared with untreated control worms, and subtle morphological alterations were detected in the ovaries of female worms. Chemical knockdown of Sj-RIOK-1 with toyocamycin (a specific RIOK-1 inhibitor robe) caused a substantial reduction in worm viability and a major accumulation of mature oocytes in the seminal receptacle (female worms), and of spermatozoa in the sperm vesicle (male worms). These phenotypic alterations indicate that the function of Sj-riok-1 is linked to developmental and/or reproductive processes in S. japonicum.
Mitochondrial phylogenomics yields strongly supported hypotheses for ascaridomorph nematodes
Publisher: Springer Science and Business Media LLC
Date: 16-12-2016
DOI: 10.1038/SREP39248
Abstract: Ascaridomorph nematodes threaten the health of humans and other animals worldwide. Despite their medical, veterinary and economic importance, the identification of species lineages and establishing their phylogenetic relationships have proved difficult in some cases. Many working hypotheses regarding the phylogeny of ascaridomorphs have been based on single-locus data, most typically nuclear ribosomal RNA. Such single-locus hypotheses lack independent corroboration, and for nuclear rRNA typically lack resolution for deep relationships. As an alternative approach, we analyzed the mitochondrial (mt) genomes of anisakids (~14 kb) from different fish hosts in multiple countries, in combination with those of other ascaridomorphs available in the GenBank database. The circular mt genomes range from 13,948-14,019 bp in size and encode 12 protein-coding genes, 2 ribosomal RNAs and 22 transfer RNA genes. Our analysis showed that the Pseudoterranova decipiens complex consists of at least six cryptic species. In contrast, the hypothesis that Contracaecum ogmorhini represents a complex of cryptic species is not supported by mt genome data. Our analysis recovered several fundamental and uncontroversial ascaridomorph clades, including the monophyly of superfamilies and families, except for Ascaridiidae, which was consistent with the results based on nuclear rRNA analysis. In conclusion, mt genome analysis provided new insights into the phylogeny and taxonomy of ascaridomorph nematodes.
Antibody responses against natural Taenia hydatigena infection in dogs in Kenya
Publisher: Elsevier BV
Date: 04-1991
DOI: 10.1016/0020-7519(91)90017-2
Abstract: Antibody responses (IgG) against Taenia hydatigena infection in dogs in Kenya were analysed in ELISA using excretory/secretory products of T. hydatigena scoleces derived from goat cysticercus cysts. Helminth infections of in idual dogs were confirmed at autopsy. T. hydatigena worms were found in 89.5% of 143 dogs, and positive anti-T. hydatigena antibody levels were detected in 58.7% of infected dogs. Positive antiscolex antibody levels were detected in 40.0% of Turkana dogs uninfected with T. hydatigena, suggesting previous infection. Antibody was not detected in 34.4% of infected dogs. There was no relationship between in idual T. hydatigena worm burdens and absorbance values for sera in ELISA. It was not possible to distinguish between sera from T. hydatigena-infected and uninfected dogs.
Natural Compounds from the Marine Brown Alga Caulocystis cephalornithos with Potent In Vitro-Activity against the Parasitic Nematode Haemonchus contortus
Publisher: MDPI AG
Date: 09-07-2020
Abstract: Eight secondary metabolites (1 to 8) were isolated from a marine sponge, a marine alga and three terrestrial plants collected in Australia and subsequently chemically characterised. Here, these natural product-derived compounds were screened for in vitro-anthelmintic activity against the larvae and adult stages of Haemonchus contortus (barber’s pole worm)—a highly pathogenic parasitic nematode of ruminants. Using an optimised, whole-organism screening system, compounds were tested on exsheathed third-stage larvae (xL3s) and fourth-stage larvae (L4s). Anthelmintic activity was initially evaluated on these stages based on the inhibition of motility, development and/or changes in morphology (phenotype). We identified two compounds, 6-undecylsalicylic acid (3) and 6-tridecylsalicylic acid (4) isolated from the marine brown alga, Caulocystis cephalornithos, with inhibitory effects on xL3 and L4 motility and larval development, and the induction of a “skinny-straight” phenotype. Subsequent testing showed that these two compounds had an acute nematocidal effect (within 1–12 h) on adult males and females of H. contortus. Ultrastructural analysis of adult worms treated with compound 4 revealed significant damage to subcuticular musculature and associated tissues and cellular organelles including mitochondria. In conclusion, the present study has discovered two algal compounds possessing acute anthelmintic effects and with potential for hit-to-lead progression. Future work should focus on undertaking a structure-activity relationship study and on elucidating the mode(s) of action of optimised compounds.
Veterinary parasitology teaching in eastern Australia
Publisher: Elsevier BV
Date: 10-2002
DOI: 10.1016/S0304-4017(02)00229-7
Abstract: There are tendencies in universities globally to change undergraduate teaching in veterinary parasitology. To be able to give considered advice to universities, faculties, governmental bodies and professional societies about a discipline and to establish how particular changes may impact on the quality of a course, is the requirement to record and review its current status. The present paper contributes toward this objective by providing a "snap-shot" of the veterinary parasitology courses at the Universities of Melbourne, Sydney and Queensland in eastern Australia. It includes a description of the veterinary science curriculum in each institution, and provides an outline of its veterinary parasitology course, including objectives, topics covered, course delivery, student examination procedures and course evaluation. Student contact time in veterinary parasitology during the curriculum is currently higher in Melbourne (183 h) compared with Sydney and Queensland (106-110 h). In the teaching of parasitology, Melbourne adopts a taxonomic approach (in the pre-clinical period) followed by a combined disciplinary and problem-based approach in the clinical semesters, whereas both Sydney and Queensland focus more on presenting parasites on a host species-basis followed by a problem-based approach.
Opisthorchis viverrini Draft Genome – Biomedical Implications and Future Avenues
Publisher: Elsevier
Date: 2018
DOI: 10.1016/BS.APAR.2018.05.005
Abstract: Opisthorchiasis is a neglected tropical disease of major proportion, caused by the carcinogenic, Asian liver fluke, Opisthorchis viverrini. This hepatobiliary disease is known to be associated with malignant cancer (cholangiocarcinoma, CCA) and affects millions of people in Southeast Asia. No vaccine is available, and only one drug (praziquantel) is routinely employed against the parasite. Despite technological advances, little is known about the molecular biology of the fluke itself and the disease complex that it causes in humans. The advent of high-throughput nucleic acid sequencing and bioinformatic technologies is enabling researchers to gain global insights into the molecular pathways and processes in parasites. The principal aims of this chapter are to (1) review molecular research of O. viverrini and opisthorchiasis (2) provide an account of recent advances in the sequencing and characterization of the genome and transcriptomes of O. viverrini (3) describe the complex life of this worm in the biliary system of the definitive (human) host and how the fluke interacts with this host and causes disease at the molecular level (4) discuss the implications of systems biological research and (5) consider how progress in genomics and informatics might enable explorations of O. viverrini and related worms and the discovery of new interventions against opisthorchiasis and CCA.
Comparison of bronchoalveolar lavage fluid examination and other diagnostic techniques with the Baermann technique for detection of naturally occurring Aelurostrongylus absttusus infection in cats
Publisher: American Veterinary Medical Association (AVMA)
Date: 07-2009
Abstract: Objective —To evaluate the diagnostic sensitivity and specificity of bronchoalveolar lavage (BAL) fluid examination and other diagnostic techniques, compared with the use of the Baermann technique performed on fecal s les as the reference standard, for detection of naturally occurring Aelurostrongylus abstrusus infection in a population of cats. Design —Cross-sectional study. S le Population —Cadavers of 80 semiferal domestic cats. Procedures —BAL fluid collection and analysis, necropsy, examination of fecal s les and minced lung tissue via the Baermann technique, fecal sedimentation-flotation, and histologic examination of lung tissue were performed. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for detection of A abstrusus infection were calculated. Results —On the basis of fecal Baermann test results, prevalence of infection was 13.8%. Sensitivity (NPV) of tests was as follows: Baermann technique on minced lung tissue, 81.8% (97.2%) fecal flotation-sedimentation, 63.6% (94.5%) stereomicroscopic examination of BAL fluid combined with cytologic examination of BAL fluid, 54.5% (93.2%) stereomicroscopic examination of BAL fluid alone, 45.4% (92.0%) cytologic examination of BAL fluid alone, 36.4% (90.8%) histologic examination of lung tissue, 45.4% (91.8%) and gross lung appearance, 36.4% (90.8%). Specificity and PPV of all tests were 100%, with the exception of histologic examination of lung tissue (specificity, 97.1% PPV, 71.4%), which identified infected cats that had negative fecal Baermann test results. Conclusions and Clinical Relevance —The Baermann technique was the most sensitive test for detection of A abstrusus infection. On the basis of the prevalence of 13.8% in this study, A abstrusus infection should be considered in pet cats.
Giardia/giardiasis - A perspective on diagnostic and analytical tools
Publisher: Elsevier BV
Date: 03-2014
DOI: 10.1016/J.BIOTECHADV.2013.10.009
Abstract: Giardiasis is a gastrointestinal disease of humans and other animals caused by species of parasitic protists of the genus Giardia. This disease is transmitted mainly via the faecal-oral route (e.g., in water or food) and is of socioeconomic importance worldwide. The accurate detection and genetic characterisation of the different species and population variants (usually referred to as assemblages and/or sub-assemblages) of Giardia are central to understanding their transmission patterns and host spectra. The present article provides a background on Giardia and giardiasis, and reviews some key techniques employed for the identification and genetic characterisation of Giardia in biological s les, the diagnosis of infection and the analysis of genetic variation within and among species of Giardia. Advances in molecular techniques provide a solid basis for investigating the systematics, population genetics, ecology and epidemiology of Giardia species and genotypes as well as the prevention and control of giardiasis.
High resolution melting-curve (HRM) analysis for the diagnosis of cryptosporidiosis in humans
Publisher: Elsevier BV
Date: 02-2009
DOI: 10.1016/J.MCP.2008.10.003
Abstract: Cryptosporidiosis of humans is an intestinal disease caused predominantly by infection with Cryptosporidium hominis or C. parvum. This disease is transmitted mainly via the faecal-oral route (water or food) and has major socioeconomic impact globally. The diagnosis and genetic characterization of the main species and population variants (also called "genotypes" and "subgenotypes") of Cryptosporidium infecting humans is central to the prevention, surveillance and control of cryptosporidiosis, particularly as there is presently no cost effective anti-cryptosporidial chemotherapeutic regimen or vaccine available. In the present study, we established a polymerase chain reaction (PCR)-coupled high resolution melting-curve (HRM) analysis method, utilizing the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA as the genetic marker, for the diagnosis of Cryptosporidium hominis, C. parvum or C. meleagridis infection. An evaluation of the method revealed intra- and inter-assay variabilities of <1.5 and 3.5%, respectively. Cryptosporidium hominis, C. parvum and C. meleagridis were detected in 97, 44 and 2, respectively, of the 143 Cryptosporidium oocyst DNA s les originating from Australians with clinical cryptosporidiosis. The melting profiles characterized by peaks of 72.47+/-0.33 degrees C and 74.19+/-0.45 degrees C (profile 1), 72.17+/-0.32 degrees C (profile 2) and 73.33+/-0.03 degrees C (profile 3) genetically identified as C. hominis, C. parvum and C. meleagridis, respectively. In conclusion, PCR-coupled melting analysis of ITS-2 achieved the diagnosis of Cryptosporidium hominis, C. parvum or C. meleagridis infection. This approach is well suited for the rapid screening of large numbers of Cryptosporidium oocyst DNA s les and, although qualitative, is significantly less time-consuming to carry out than electrophoretic analysis and has the added advantage of data storage and analysis capabilities in silico. This method provides a useful tool for investigating the epidemiology and outbreaks of cryptosporidiosis, and could be applicable to species of Cryptosporidium other than those investigated herein.
Genome of the human hookworm Necator americanus
Publisher: Springer Science and Business Media LLC
Date: 19-01-2014
DOI: 10.1038/NG.2875
Molecular Changes in Opisthorchis viverrini (Southeast Asian Liver Fluke) during the Transition from the Juvenile to the Adult Stage
Publisher: Public Library of Science (PLoS)
Date: 29-11-2012
Whipworm kinomes reflect a unique biology and adaptation to the host animal
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.IJPARA.2017.04.005
Abstract: Roundworms belong to a erse phylum (Nematoda) which is comprised of many parasitic species including whipworms (genus Trichuris). These worms have adapted to a biological niche within the host and exhibit unique morphological characteristics compared with other nematodes. Although these adaptations are known, the underlying molecular mechanisms remain elusive. The availability of genomes and transcriptomes of some whipworms now enables detailed studies of their molecular biology. Here, we defined and curated the full complement of an important class of enzymes, the protein kinases (kinomes) of two species of Trichuris, using an advanced and integrated bioinformatic pipeline. We investigated the transcription of Trichuris suis kinase genes across developmental stages, sexes and tissues, and reveal that selectively transcribed genes can be linked to central roles in developmental and reproductive processes. We also classified and functionally annotated the curated kinomes by integrating evidence from structural modelling and pathway analyses, and compared them with other curated kinomes of phylogenetically erse nematode species. Our findings suggest unique adaptations in signalling processes governing worm morphology and biology, and provide an important resource that should facilitate experimental investigations of kinases and the biology of signalling pathways in nematodes.
Detection of diarrhoeal pathogens in human faeces using an automated, robotic platform
Publisher: Elsevier BV
Date: 02-2012
DOI: 10.1016/J.MCP.2011.10.004
Abstract: Infectious diarrhoeal diseases represent a major socio-economic burden to humans, and are linked to a range of pathogens, including viruses, bacteria and protists. The accurate detection of such pathogens is central to control. However, detection often relies on methods that have limited diagnostic sensitivity and specificity. Here, we assessed an automated, robotic platform for the simultaneous detection of eight major pathogens associated with infectious diarrhoea. Genomic DNA s les (n = 167) from faeces from humans with diarrhoea and diagnosed as cryptosporidiosis, and 100 uninfected control subjects, were tested for adenovirus 40/41, norovirus, Clostridium difficile, C ylobacter, Salmonella, Shigella, Cryptosporidium and Giardia by multiplexed-tandem PCR, and also characterized by single-strand conformation polymorphism analysis (SSCP) and selective sequencing. All 167 s les tested positive for Cryptosporidium, five for adenovirus 40/41, four for C ylobacter, three for C. difficile and seven for Shigella spp., with no false positive results for any assay. The automated PCR exhibited a high sensitivity, with <10 in idual pathogens being readily detected. The robotic detection platform assessed here represents a sensitive, high-throughput tool for key pathogens linked to infectious diarrhoea in humans. This platform requires little molecular biological expertise and is well suited to various diagnostic facilities and settings.
SCP/TAPS proteins in helminths - Where to from now?
Publisher: Elsevier BV
Date: 02-2012
DOI: 10.1016/J.MCP.2011.10.001
Abstract: A erse array of proteins belonging to the SCP/TAPS 'family' has been described for various eukaryotic organisms, including parasites. Although SCP/TAPS proteins have been hypothesized to play key roles in various fundamental biological processes, such as host-pathogen interactions and defence mechanisms, there is still a limited understanding of the precise roles of these proteins. Here, we review current knowledge of key SCP/TAPS proteins of helminths and their proposed roles in parasite-host interactions. Molecular investigations of these molecules in parasites and the integration of structural and functional data could lead to new and innovative approaches for the treatment and control of parasitic diseases, with important biotechnological outcomes.
Low cost whole-organism screening of compounds for anthelmintic activity
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.IJPARA.2015.01.007
Abstract: Due to major problems with drug resistance in parasitic nematodes of animals, there is a substantial need and excellent opportunities to develop new anthelmintics via genomic-guided and/or repurposing approaches. In the present study, we established a practical and cost-effective whole-organism assay for the in vitro-screening of compounds for activity against parasitic stages of the nematode Haemonchus contortus (barber's pole worm). The assay is based on the use of exsheathed L3 (xL3) and L4 stages of H. contortus of small ruminants (sheep and goats). Using this assay, we screened a panel of 522 well-curated kinase inhibitors (GlaxoSmithKline, USA code: PKIS2) for activity against H. contortus by measuring the inhibition of larval motility using an automated image analysis system. We identified two chemicals within the compound classes biphenyl amides and pyrazolo[1,5-α]pyridines, which reproducibly inhibit both xL3 and L4 motility and development, with IC50s of 14-47 μM. Given that these inhibitors were designed as anti-inflammatory drugs for use in humans and fit the Lipinski rule-of-five (including bioavailability), they show promise for hit-to-lead optimisation and repurposing for use against parasitic nematodes. The screening assay established here has significant advantages over conventional methods, particularly in terms of ease of use, throughput, time and cost. Although not yet fully automated, the current assay is readily suited to the screening of hundreds to thousands of compounds for subsequent hit-to-lead optimisation. The current assay is highly adaptable to many parasites of socioeconomic importance, including those causing neglected tropical diseases. This aspect is of major relevance, given the urgent need to deliver the goals of the London Declaration (esource/london-declaration) through the rapid and efficient repurposing of compounds in public-private partnerships.
Digerati – A multipath parallel hybrid deep learning framework for the identification of mycobacterial PE/PPE proteins
Publisher: Elsevier BV
Date: 09-2023
Disseminated protozoal infection in a wild feathertail glider (Acrobates pygmaeus) in Australia
Publisher: Elsevier BV
Date: 12-2020
High-throughput capillary electrophoresis for the identification and differentiation of seven species ofEimeria from chickens
Publisher: Wiley
Date: 09-2005
Abstract: A capillary electrophoretic approach has been evaluated for the identification of seven currently recognised species of Eimeria infecting chickens. The second internal transcribed spacer of ribosomal DNA is PCR- lified from any of the seven species using a single set of oligonucleotide primers (one of which is fluorescently labelled). The licons are heat-denatured and subjected to capillary electrophoresis in a MegaBACE 1000 (Amersham). The chromatograms captured are stored electronically and then analysed using MegaBACE Fragment Profiler software. Using control DNA s les representing monospecific lines of Eimeria, specific peaks in the chromatograms were defined for the unequivocal identification of each of the seven species and their differentiation. Electrophoretic reading and analysis are carried out automatically, thus making it a time- and cost-effective method. This procedure should find applicability as a tool for the quality control of Eimeria vaccines, the monitoring of coccidiosis outbreaks and the high-throughput analysis of oocyst s les for epidemiological surveys.
Evidence for hybridisation between Paramacropostrongylus iugalis and P. typicus (Nematoda: Strongyloidea) in grey kangaroos, Macropus fuliginosus and M. giganteus, in a zone of sympatry in Eastern Australia
Publisher: Elsevier BV
Date: 05-1997
DOI: 10.1016/S0020-7519(97)00024-6
Abstract: Specimens of Paramacropostrongylus iugalis and P. typicus, collected from eastern (Macropus giganteus) and western (M. fuliginosus) grey kangaroos in New South Wales and Queensland, were examined morphologically and electrophoretically at 4 enzyme loci previously demonstrated to be diagnostic between the 2 species. Collections of P. iugalis from M. giganteus from outside the zone of sympatry of the 2 kangaroo species conformed electrophoretically and morphologically with previous studies. Within the zone of sympatry, the 2 nematode species were distinguishable electrophoretically, with most P. iugalis occurring in M. giganteus and all P. typicus occurring in M. fuliginosus. Some specimens of P. iugalis were identified in M. fuliginosus and, in both host species, nematodes were encountered with electrophoretic profiles intermediate between P. iugalis and P. typicus. The frequent occurrence in these specimens of heterozygotes suggested that the genetic barriers between the 2 nematode species were not complete and that genetic interchange (i.e. hybridisation) was occurring.
Cracking the nodule worm code advances knowledge of parasite biology and biotechnology to tackle major diseases of livestock
Publisher: Elsevier BV
Date: 11-2015
Use of Echinococcus granulosus worm antigens for immunodiagnosis of E. granulosus infection in dogs
Publisher: Elsevier BV
Date: 12-1992
DOI: 10.1016/0304-4017(92)90030-D
Abstract: Echinococcus granulosus worm excretory/secretory antigens (WES) were used in ELISA for diagnosis of E. granulosus infection in dogs and compared with protoscolex somatic antigens (PSM). Sera from 224 dogs were tested. There was no correlation between ELISA absorbance values and E. granulosus worm burdens using either antigen. There was a significant linear relationship between absorbance values of sera tested in the ELISA using WES (W-ELISA) and the ELISA using PSM (P-ELISA). However, there was a small but significant difference between the absorbance values of the sera tested against the two antigens. Western blot analysis of WES using sera from E. granulosus-infected and uninfected dogs revealed antigenic components of relative molecular mass (Mr) larger than 94,000, Mr 94,000-68,000 and Mr 43,000-39,000 in worms, and these were specific for E. granulosus and not identified in PSM these antigenic differences may be responsible for differences in reactivity in ELISA. The sensitivities of W-ELISA and P-ELISA were 80.8% and 75.6%, respectively. The specificities of W-ELISA and P-ELISA were 93.7% and 97.9%, respectively. The reduced specificity in W-ELISA was mainly attributable to increased background reactivity of sera from Taenia hydatigena-infected dogs. Despite the reduction in specificity, both ELISAs are valuable epidemiological tools to determine the prevalence of antibody to E. granulosus in dog populations and to monitor the success of hydatid control c aigns.
The apicoplast genomes of two taxonomic units of Babesia from sheep.
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.VETPAR.2016.11.004
Abstract: The apicoplast (ap) is a unique, non-photosynthetic organelle found in most apicomplexan parasites. Due to the essential roles that this organelle has, it has been widely considered as target for drugs against diseases caused by apicomplexans. Exploring the ap genomes of such parasites would provide a better understanding of their systematics and their basic molecular biology for therapeutics. However, there is limited information available on the ap genomes of apicomplexan parasites. In the present study, the ap genomes of two operational taxonomic units of Babesia (known as Babesia sp. Lintan [Bl] and Babesia sp. Xinjiang [Bx]) from sheep were sequenced, assembled and annotated using a massive parallel sequencing-based approach. Then, the gene content and gene order in these ap genomes (∼30.7kb in size) were defined and compared, and the genetic differences were assessed. In addition, a phylogenetic analysis of ap genomic data sets was carried out to assess the relationships of these taxonomic units with other apicomplexan parasites for which complete ap genomic data sets were publicly available. The results showed that the ap genomes of Bl and Bx encode 59 and 57 genes, respectively, including 2 ribosomal RNA genes, 25 transfer RNA genes and 30-32 protein-encoding genes, being similar in content to those of Babesia bovis and B. orientalis. Ap gene regions that might serve as markers for future epidemiological and population genetic studies of Babesia species were identified. Using sequence data for a subset of six protein-encoding genes, a close relationship of Bl and Bx with Babesia bovis from cattle and B. orientalis from water buffalo was inferred. Although the focus of the present study was on Babesia, we propose that the present sequencing-bioinformatic approach should be applicable to organellar genomes of a wide range of apicomplexans of veterinary importance.
Norcantharidin analogues with nematocidal activity in Haemonchus contortus.
Publisher: Elsevier BV
Date: 06-2011
DOI: 10.1016/J.BMCL.2011.04.031
Abstract: With the major problems with resistance in parasitic nematodes of livestock to anthelmintic drugs, there is an urgent need to develop new nematocides. In the present study, we employed a targeted approach for the design of a series of norcantharidin analogues (n=54) for activity testing against the barber's pole worm (Haemonchus contortus) of small ruminants in a larval development assay (LDA) and also for toxicity testing on nine distinct human cell lines. Although none of the 54 analogues synthesized were toxic to any of these cell lines, three of them (N-octyl-7-oxabicyclo(2.2.1)heptane-2,3-dicarboximide (B2), N-decyl-7-oxabicyclo(2.2.1)heptane-2,3-dicarboximide (B3) and 4-[(4-methyl)-3-ethyl-2-methyl-5-phenylfuran-10-oxa-4-azatricyclo[5.2.1]decane-3,5-dione (B21) reproducibly displayed 99-100% lethality to H. contortus in LDA, with LD(50s) of 25-40 μM. The high 'hit rate' (5.6%) indicates that the approach taken here has advantages over conventional drug screening methods. A major advantage of norcantharidin analogues over some other currently available anthelmintics is that they can be produced in one to two steps in large amounts at low cost and high purity, and do not require any additional steps for the isolation of the active isomer. This positions them well for commercial development.
Investigating the first outbreak of oriental theileriosis in cattle in South Australia using multiplexed tandem PCR (MT-PCR)
Publisher: Elsevier BV
Date: 07-2015
DOI: 10.1016/J.TTBDIS.2015.04.012
Abstract: This study investigated the first outbreak of oriental theileriosis in a herd of beef cattle in South Australia using a newly established multiplexed tandem PCR (MT-PCR) to identify, differentiate and quantitate the four genotypes (buffeli, chitose, ikeda and type 5) of Theileria orientalis recognised to occur in Australasia. Following clinical diagnosis of oriental theileriosis (based on clinical signs, laboratory findings and post mortem examination), 155 blood s les were collected from in idual cows (n = 85) and calves (n = 70), and tested by MT-PCR. In total, 117 (75.48%) cattle were shown to be test-positive for T. orientalis. All four genotypes were detected, and ikeda had the highest prevalence (90.6% 106/117), followed by buffeli (83.8% 98/117), chitose (18.8% 22/117) and type 5 (5.1% 6/117). Mixed infections with genotypes buffeli and ikeda had a higher prevalence (55.5% 65/117) than any other combination of genotypes. The prevalences of buffeli and ikeda were significantly higher (P<0.005) than those of chitose and type 5. The average intensity of infection with genotype ikeda (329,775 DNA copies) was significantly higher (P<0.0001) than buffeli (212,843) and chitose (125,462). This study reinforces the utility of MT-PCR as a diagnostic tool for rapidly investigating oriental theileriosis outbreaks in cattle herds and as a pre-movement screening test for preventing the introduction of this disease into non-endemic regions.
Serine/threonine protein phosphatase 1 (PP1) controls growth and reproduction inSchistosoma japonicum
Publisher: Wiley
Date: 07-06-2018
Phylogenetic Relationships of the Strongyloid Nematodes of Australasian Marsupials Based on Mitochondrial Protein Sequences
Publisher: MDPI AG
Date: 22-10-2022
DOI: 10.3390/ANI12212900
Abstract: Australasian marsupials harbour a erse group of gastrointestinal strongyloid nematodes. These nematodes are currently grouped into two subfamilies, namely the Cloacininae and Phascolostrongylinae. Based on morphological criteria, the Cloacininae and Phascolostrongylinae were defined as monophyletic and placed in the family Cloacinidae, but this has not been supported by molecular data and they are currently placed in the Chabertiidae. Although molecular data (internal transcribed spacers of the nuclear ribosomal RNA genes or mitochondrial protein-coding genes) have been used to verify morphological classifications within the Cloacininae and Phascolostrongylinae, the phylogenetic relationships between the subfamilies have not been rigorously tested. This study determined the phylogenetic relationships of the subfamilies Cloacininae and Phascolostrongylinae using amino acid sequences conceptually translated from the twelve concatenated mitochondrial protein-coding genes. The findings demonstrated that the Cloacininae and Phascolostrongylinae formed a well-supported monophyletic assemblage, consistent with their morphological classification as an independent family, Cloacinidae. Unexpectedly, however, the subfamily Phascolostrongylinae was split into two groups comprising the genera from macropodid hosts (kangaroos and wallabies) and those from vombatid hosts (wombats). Genera of the Cloacininae and Phascolostrongylinae occurring in macropodid hosts were more closely related compared to genera of the Phascolostrongylinae occurring in wombats that formed a sister relationship with the remaining genera from macropods. These findings provide molecular evidence supporting the monophyly of the family Cloacinidae and an alternative hypothesis for the origin of marsupial strongyloid nematodes in vombatid hosts that requires further exploration using molecular approaches and additional s les
Single-strand restriction fragment length polymorphism analysis of the second internal transcribed spacer (ribosomal DNA) for six species of Eimeria from chickens in Australia
Publisher: Elsevier BV
Date: 08-2000
DOI: 10.1016/S0020-7519(00)00084-9
Abstract: Species of Eimeria from chickens from Australia were characterised using a polymerase chain reaction-linked restriction fragment length polymorphism (PCR-RFLP) approach. The ribosomal DNA region spanning the second internal transcribed spacer (ITS-2) was lified from genomic DNA by PCR, digested separately with three restriction endonucleases (CfoI, Sau3AI and TaqI) and the fragments separated by denaturing gel electrophoresis. The PCR products lified from the six species varied from approximately 70 to 620 bp on agarose gels, with differences in size and number of bands among species, but no apparent variation within a species. The PCR-RFLP analysis of ITS-2 licons on denaturing gels gave characteristic profiles for in idual species (except for minor variation in profiles within some species). The results indicate that ITS-2 contains useful genetic markers for the identification of six Eimeria species occurring in Australia.
Exploring the role of two interacting phosphoinositide 3-kinases of Haemonchus contortus
Publisher: Springer Science and Business Media LLC
Date: 12-11-2014
iFeatureOmega: an integrative platform for engineering, visualization and analysis of features from molecular sequences, structural and ligand data sets
Publisher: Oxford University Press (OUP)
Date: 07-05-2022
DOI: 10.1093/NAR/GKAC351
Abstract: The rapid accumulation of molecular data motivates development of innovative approaches to computationally characterize sequences, structures and functions of biological and chemical molecules in an efficient, accessible and accurate manner. Notwithstanding several computational tools that characterize protein or nucleic acids data, there are no one-stop computational toolkits that comprehensively characterize a wide range of biomolecules. We address this vital need by developing a holistic platform that generates features from sequence and structural data for a erse collection of molecule types. Our freely available and easy-to-use iFeatureOmega platform generates, analyzes and visualizes 189 representations for biological sequences, structures and ligands. To the best of our knowledge, iFeatureOmega provides the largest scope when directly compared to the current solutions, in terms of the number of feature extraction and analysis approaches and coverage of different molecules. We release three versions of iFeatureOmega including a webserver, command line interface and graphical interface to satisfy needs of experienced bioinformaticians and less computer-savvy biologists and biochemists. With the assistance of iFeatureOmega, users can encode their molecular data into representations that facilitate construction of predictive models and analytical studies. We highlight benefits of iFeatureOmega based on three research applications, demonstrating how it can be used to accelerate and streamline research in bioinformatics, computational biology, and cheminformatics areas. The iFeatureOmega webserver is freely available at ifeatureomega.erc.monash.edu and the standalone versions can be downloaded from github.com/Superzchen/iFeatureOmega-GUI/ and github.com/Superzchen/iFeatureOmega-CLI/.
Identification of G protein-coupled receptors in Schistosoma haematobium and S. mansoni by comparative genomics
Publisher: Springer Science and Business Media LLC
Date: 27-05-2014
Investigation of the regulation of transcriptional changes in Ancylostoma caninum larvae following serum activation, with a focus on the insulin-like signalling pathway
Publisher: Elsevier BV
Date: 02-2009
DOI: 10.1016/J.VETPAR.2008.10.026
Abstract: The exit from dauer in the free-living nematode Caenorhabditis elegans is under the control of a single hidial neuron (ASJ) of the insulin-like signalling pathway. Mutations of this pathway have the ability to suppress entry into the dauer stage. It has been postulated that insulin-like signalling plays a significant role in the response to serum stimulation in vitro of the third-stage larvae (L3s) of the canine hookworm Ancylostoma caninum. To test for the possible involvement of the insulin-like signalling cascade in the response to serum stimulation, the effects of two signalling stimulants (8-bromo cGMP and arecoline) and four inhibitors, namely 4,7-phenanthroline, phosphoinositide-3 kinase (PI3K), Akt inhibitor IV and rapamycin on feeding and on levels of selected activation-associated mRNAs in serum-stimulated L3s were explored. L3s of A. caninum were pre-incubated with or without the appropriate inhibitor/agonist. Following serum-stimulation, the feeding activity was assessed. The transcription levels of a number of activation-associated mRNAs linked to particular expressed sequence tags (ESTs) were investigated by reverse transcription, real-time PCR (rtPCR). The treatment of worms with 4,7-phenanthroline completely suppressed feeding and significantly reduced the differential levels of most activation-associated mRNAs, whereas the treatment with cGMP resulted in the resumption of feeding in almost 85% of the L3s and yielded a specific transcriptional profile consistent with that following serum stimulation. The treatment of L3s with arecoline resulted in the resumption of feeding in approximately 85% of L3s, but did not result in a transcriptomic profile consistent with activation. A complete reduction in feeding was recorded in the presence of the PI3K inhibitor LY294002 (1mM) and resulted in a pronounced d ening of differential transcription in response to serum stimulation for the molecules examined. Akt inhibitor IV resulted in a approximately 70% reduction in feeding but had almost no effect on the level of any of the activation-associated mRNAs studied. Rapamycin was shown to have a weak effect on feeding, and several of the mRNAs studied exhibited greater than expected transcription following treatment. The complexities of activation-associated transcription could not be addressed using the current approach. A larger number of mRNAs needs to be investigated in order to predict or identify regulatory mechanisms proposed to function in the insulin-like signalling pathway in A. caninum.
Mitochondrial genomes of two Babesia taxa from sheep in China as a foundation for population genetic and epidemiological investigations.
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.MEEGID.2016.11.002
Abstract: Here, we sequenced, assembled and annotated the mitochondrial (mt) genomes of two operational taxonomic units of Babesia from sheep from China using a deep sequencing-coupled approach. Then, we defined and compared the gene order of these mt genomes (~5.8 to 6.2kb in size), assessed sequence differences in mt genes among Babesia taxa and evaluated genetic relationships among these taxa and related apicomplexans (Theileria) for which mt genomic data sets were available. We also identified mt genetic regions that might be useful as markers for future population genetic and molecular epidemiological studies of Babesia from small ruminants. We propose that the sequencing-bioinformatic approach used here should be applicable to a wide range of protists of veterinary importance.
Optimization of Novel 1-Methyl-1H-Pyrazole-5-carboxamides Leads to High Potency Larval Development Inhibitors of the Barber’s Pole Worm
Publisher: American Chemical Society (ACS)
Date: 07-11-2018
DOI: 10.1021/ACS.JMEDCHEM.8B01544
Abstract: A phenotypic screen of a erse library of small molecules for inhibition of the development of larvae of the parasitic nematode Haemonchus contortus led to the identification of a 1-methyl-1 H-pyrazole-5-carboxamide derivative with an IC
A perfect time to harness advanced molecular technologies to explore the fundamental biology of Toxocara species
Publisher: Elsevier BV
Date: 04-2013
DOI: 10.1016/J.VETPAR.2012.12.031
Abstract: Toxocarosis is of major canine health and socioeconomic importance worldwide. Although many studies have given insights into toxocarosis, to date, there has been limited exploration of the molecular biology, biochemistry, genetics, epidemiology and ecology of Toxocara species as well as parasite-host interactions using '-omic' technologies. The present article gives a background on Toxocara species and toxocarosis, describes molecular tools for specific identification and genetic analysis, and provides a prospective view of the benefits that advanced molecular technologies will have towards better understanding the parasites and disease. Tackling key biological questions employing a 'systems biology' approach should lead to new and improved strategies for the treatment, diagnosis and control of toxocarosis.
Specific amplification ofNecator americanusorAncylostoma duodenaleDNA by PCR using markers in ITS-1 rDNA, and its implications
Publisher: Elsevier BV
Date: 04-1998
Abstract: Necator americanus and Ancylostoma duodenale are the two most important species of human hookworm, and occur in sympatry over much of their distribution. The specific diagnosis of hookworm infections is central to control. Diagnosis currently relies on the detection of hookworm eggs in human faeces and/or the specific identification of larvae by 'copro-culture' combined with microscopic examination. However, the eggs of the two species are morphologically indistinguishable, and the procedure of copro-culture is tedious and time-consuming to carry out. To work toward overcoming these limitations, a molecular approach utilizing genetic markers in the first internal transcribed spacer (ITS-1) of ribosomal DNA (rDNA) was established. The ITS-1 sequences of both hookworm species were determined, and specific oligonucleotide primers designed to regions of major sequence difference between the species were evaluated in polymerase chain reaction (PCR). Using a range of control s les, the primers allowed the specific identification of as little as 10 pg DNA of A. duodenale or N. americanus. The findings indicate clearly the potential for specific PCR to confirm the identity of eggs from faeces and larvae from the environment or host tissues. This should have important implications for studying fundamental aspects relating to anthelmintic efficacy and the epidemiology of hookworms.
Characterization of major sperm protein genes and their expression in Oesophagostomum dentatum (Nematoda: Strongylida)
Publisher: Cambridge University Press (CUP)
Date: 10-2004
DOI: 10.1017/S003118200400561X
Abstract: Major sperm protein (msp) genes were isolated from complementary (cDNA) and genomic DNA libraries prepared from the parasitic nematode, Oesophagostomum dentatum, characterized at the nucleotide and amino acid (aa) levels, and their expression was investigated. Three different msp cDNA and 2 genomic sequences were determined, each with an open reading frame (ORF) of 381 nucleotides. Nucleotide variation was detected at 30 positions in the ORF among all 5 sequences. Conceptual translation of the full-length msp sequences inferred 4 different MSPs each of 126 aa. These predicted MSPs differed at aa positions 15 (serine threonine), 101 (alanine glycine), 103 (glutamine leucine) and 126 (proline leucine). Southern blot analysis of O. dentatum genomic DNA, digested separately with various restriction endonucleases, displayed multiple (n = 7-13) bands for each enzyme, providing support for a multigene family. Also, at the genomic level, sequence tracts consistent with a 'substitute' TATA box sequence motif were identified within a region (-1 to -123 nt) preceding the 2 msp genes. In contrast to other species of nematode investigated to date, no GATA transcription factor binding motif was detected immediately upstream of the msp coding region. Real-time PCR analysis demonstrated that msp mRNA was expressed exclusively in the males of both fourth-stage larvae (L4s) and adults of O. dentatum (raised in pigs after intragastric inoculation). The magnitude of expression in male O. dentatum raised in pigs in the presence of female worms was the same as in males in the absence of females. Comparative analyses showed aa sequence conservation among MSPs from various nematodes, suggesting similar functional roles for these proteins.
Structure–Activity Relationship Studies of Tolfenpyrad Reveal Subnanomolar Inhibitors of Haemonchus contortus Development
Publisher: American Chemical Society (ACS)
Date: 20-12-2018
DOI: 10.1021/ACS.JMEDCHEM.8B01789
Abstract: Recently, we have discovered that the registered pesticide, tolfenpyrad, unexpectedly and potently inhibits the development of the L4 larval stage of the parasitic nematode Haemonchus contortus with an IC
A combined microscopic-molecular method for the diagnosis of strongylid infections in sheep
Publisher: Elsevier BV
Date: 09-2009
DOI: 10.1016/J.IJPARA.2009.03.002
Abstract: We evaluated a combined microscopic-molecular approach for the diagnosis of key strongylid infections in sheep using panels of well-defined control and test s les. The method established is based on the separation of nematode eggs from faecal s les using a salt flotation procedure, the extraction and column-purification of genomic DNA, followed by real-time PCR and melting-curve analysis. Specific and semi-quantitative lification from (a minimum of 0.1-2.0pg) genomic DNA of Haemonchus contortus, Teladorsagia circumcincta, Trichostrongylus spp., Cooperia oncophora, Oesophagostomum columbianum, Oesophagostomum venulosum or Chabertia ovina is achieved using a specific, forward oligonucleotide primer located in the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA (rDNA) together with a conserved reverse primer in the large subunit of rDNA. Using a panel of well-defined genomic DNA s les from eggs from sheep monospecifically infected with H. contortus or Te. circumcincta, there was a correlation between cycle threshold (Ct) values in the PCR and numbers of egg per gram of faeces, thus allowing the semi-quantitation of parasite DNA in faeces. The findings of the present study indicate that a microscopic-molecular approach provides a useful tool for diagnosis, for epidemiological and ecological surveys as well as for integration into parasite monitoring, drug resistance (i.e. 'egg count reduction') testing or control programmes, particularly following semi- or full-automation.
Ascaroside Signaling Is Widely Conserved among Nematodes
Publisher: Elsevier BV
Date: 05-2012
Assessing the Anthelmintic Candidates BLK127 and HBK4 for Their Efficacy on Haemonchus contortus Adults and Eggs, and Their Hepatotoxicity and Biotransformation
Publisher: MDPI AG
Date: 30-03-2022
DOI: 10.3390/PHARMACEUTICS14040754
Abstract: As a widely distributed parasitic nematode of ruminants, Haemonchus contortus has become resistant to most anthelmintic classes, there has been a major demand for new compounds against H. contortus and related nematodes. Recent phenotypic screening has revealed two compounds, designated as BLK127 and HBK4, that are active against H. contortus larvae. The present study was designed to assess the activity of these compounds against H. contortus eggs and adults, hepatotoxicity in rats and sheep, as well as biotransformation in H. contortus adults and the ovine liver. Both compounds exhibited no inhibitory effect on the hatching of eggs. The benzyloxy amide BLK127 significantly decreased the viability of adults in sensitive and resistant strains of H. contortus and showed no hepatotoxic effect, even at the highest concentration tested (100 µM). In contrast, HBK4 had no impact on the viability of H. contortus adults and exhibited significant hepatotoxicity. Based on these findings, HBK4 was excluded from further studies, while BLK127 seems to be a potential candidate for a new anthelmintic. Consequently, biotransformation of BLK127 was tested in H. contortus adults and the ovine liver. In H. contortus, several metabolites formed via hydroxylation, hydrolysis and glycosidation were identified, but the extent of biotransformation was low, and the total quantity of the metabolites formed did not differ significantly between the sensitive and resistant strains. In contrast, ovine liver cells metabolized BLK127 more extensively with a glycine conjugate of 4-(pentyloxy)benzoic acid as the main BLK127 metabolite.
Molecular characterisation of Theileria orientalis in imported and native bovines from Pakistan
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.MEEGID.2016.11.005
Abstract: The epidemiological aspects of Theileria orientalis in Pakistan are unknown therefore, investigations using sensitive and precise molecular techniques are required. This study reports the first molecular characterisation of T. orientalis detected from imported (Bos taurus) and native cattle (Bos indicus×Bos taurus) and buffaloes (Bubalus bubalis) selected from four districts of Punjab, Pakistan. DNA s les from blood (n=246) were extracted and tested using conventional PCR utilising the major piroplasm surface protein (MPSP) gene and multiplexed tandem PCR (MT-PCR). Theileria orientalis DNA was detected (15% 22/147) only in imported cattle by conventional PCR, whereas 24.5% (36/147), 6% (3/50) and 6.1% (3/49) of the imported cattle and native Pakistani cattle and buffaloes, respectively were test-positive for T. orientalis using MT-PCR. Using MT-PCR, the prevalence of T. orientalis was significantly higher (P<0.0001) in imported cattle compared to that of detected in native Pakistani bovines. The prevalence of T. orientalis and DNA copies of chitose and ikeda were significantly higher (P<0.05) in imported cattle than those detected in native Pakistani bovines. DNA sequencing of licons of the conventional PCR revealed the presence of buffeli, chitose and ikeda genotypes of T. orientalis. Phylogenetic analysis revealed that the MPSP sequences of buffeli, chitose and ikeda from imported cattle were closely related to those sequences reported previously from Australia and other regions. This study provides the first survey of T. orientalis infection in imported and native bovines in Pakistan, and highlights the need for future studies to understand the spread of transboundary animal diseases.
Exploring transcriptional conservation between Ancylostoma caninum and Haemonchus contortus by oligonucleotide microarray and bioinformatic analyses
Publisher: Elsevier BV
Date: 02-2009
DOI: 10.1016/J.MCP.2008.09.004
Abstract: In this study, we identified, using an established oligonucleotide microarray platform for the parasitic nematode Haemonchus contortus, transcripts that are 'conserved' between serum-activated and non-activated L3s of Ancylostoma caninum (aL3 and L3, respectively) and H. contortus by cross-species hybridization (CSH) at high stringency and conducted extensive bioinformatic analyses of the cross-hybridizing expressed sequence tags (ESTs). The microarray analysis revealed significant differential hybridization between aL3 and L3 for 32 molecules from A. caninum, of which 29 were shown to have homologues/orthologues in the free-living nematode Caenorhabditis elegans and/or A. caninum and the other three molecules had no homologues in current gene databases. 'Non-wildtype' RNAi phenotypes were recorded for 13 of the C. elegans homologues. A subset of 16 C. elegans homologues/orthologues (i.e. genes abce-1, act-2, C08H9.2, C55F2.1, calu-1, col-181, cpr-6, elo-2, asp-1, K07E3.4, rpn-2, sel-9, T28C12.4, hsb-1, Y57G11C.15 and ZK593.1) were predicted to interact genetically with a total of 156 (range 1-88) other genes. Gene ontology (GO) analysis of the interacting genes revealed that the most common subcategories were signal transduction (7%), intracellular protein transport and glycolysis (6.2%) within 'biological process' nuclear (25.7%) and intracellular (19.8%) within 'cellular component' and ATP-binding (14.4%) and protein-binding (8.4%) within 'molecular function'. The potential roles of key molecules in the two blood-feeding parasitic nematodes are discussed in relation to the known roles of their homologues/orthologues in C. elegans. The CSH approach used may provide a tool for the screening of genes conserved across a range of different taxa of parasites for which DNA microarray platforms are not available.
Analyses of Compact Trichinella Kinomes Reveal a MOS-Like Protein Kinase with a Unique N-Terminal Domain
Publisher: Oxford University Press (OUP)
Date: 09-2016
Abstract: Parasitic worms of the genus Trichinella (phylum Nematoda class Enoplea) represent a complex of at least twelve taxa that infect a range of different host animals, including humans, around the world. They are foodborne, intracellular nematodes, and their life cycles differ substantially from those of other nematodes. The recent characterization of the genomes and transcriptomes of all twelve recognized taxa of Trichinella now allows, for the first time, detailed studies of their molecular biology. In the present study, we defined, curated, and compared the protein kinase complements (kinomes) of Trichinella spiralis and T. pseudospiralis using an integrated bioinformatic workflow employing transcriptomic and genomic data sets. We examined how variation in the kinome might link to unique aspects of Trichinella morphology, biology, and evolution. Furthermore, we utilized in silico structural modeling to discover and characterize a novel, MOS-like kinase with an unusual, previously undescribed N-terminal domain. Taken together, the present findings provide a basis for comparative investigations of nematode kinomes, and might facilitate the identification of Enoplea-specific intervention and diagnostic targets. Importantly, the in silico modeling approach assessed here provides an exciting prospect of being able to identify and classify currently unknown (orphan) kinases, as a foundation for their subsequent structural and functional investigation.
Isolation and characterization of class II myosin genes from Haemonchus contortus
Publisher: Springer Science and Business Media LLC
Date: 25-03-2006
Genetic identification of an oxyurid from a captive, black-handed spider monkey--implications for treatment and control
Publisher: Springer Science and Business Media LLC
Date: 30-07-2014
DOI: 10.1007/S00436-014-4013-7
Abstract: Parasites are of major clinical significance in captive primates in zoos, particularly those with direct life cycles. Oxyurid nematodes can be a persistent problem, as infection intensity and environmental contamination with infective eggs are usually high. Observations at the Basel Zoo in Switzerland have revealed that particularly black-handed spider monkeys (Ateles geoffroyi) exhibit continuous oxyurid nematode infection(s), despite regular deworming with anthelmintics. In the present study, using a molecular approach, we were able to identify the nematode (Trypanoxyuris atelis) causing this ongoing problem, and we are now evaluating a practical treatment and control regimen to tackle this parasite problem.
First survey of parasitic helminths of goats along the Han River in Hubei Province, China
Publisher: Springer Science and Business Media LLC
Date: 2016
DOI: 10.1515/AP-2016-0080
Abstract: Diseases caused by parasitic helminths cause considerable production and economic losses in livestock worldwide. Understanding the epidemiology of these parasites has important implications for controlling them. The main purpose of the present study was to estimate the prevalence of key parasitic helminths in goats along the Han River in Zhanggang, Hubei Province (from January to December 2014). We used faecal flotation and sedimentation techniques as well as PCR-based DNA sequencing to detect and identify helminths. Results showed that the prevalence of helminths was high throughout the year, particularly for gastrointestinal nematodes. These first findings provide useful baseline information for goat helminths in Zhanggang, and a starting point for the implementation of control programs. With an increased expansion of the goat industry in China, the findings also emphasise the need to undertake prevalence surveys in other regions of China where extensive farming practices are used.
Molecular characterisation of a male-specific serine/threonine phosphatase from Oesophagostomum dentatum (Nematoda: Strongylida), and functional analysis of homologues in Caenorhabditis elegans
Publisher: Elsevier BV
Date: 03-2003
DOI: 10.1016/S0020-7519(02)00263-1
Abstract: A male-specifically expressed sequence tag was used as a probe to screen adult male Oesophagostomum dentatum (Nematoda Strongylida) gene libraries. The cDNA clones isolated coded for a serine/threonine protein phosphatase with approximately 85% identity to two Caenorhabditis elegans proteins implicated in reproduction. However, the genomic structures for the two species were distinct, in that the O. dentatum gene contained seven introns, whereas the C. elegans homologues contained three (two of which were conserved between the two nematodes). The promoters of all three nematode genes contained two putative GATA motifs separated by six to seven nucleotides and located within 100 nucleotides of the predicted transcriptional start site. RNA interference (RNAi) experiments in C. elegans, targetting the two homologues, revealed a consistent reduction in the number of progeny produced by treated worms, indicating a functional role in reproduction. Expression of green fluorescent protein, directed by the putative promoters for the C. elegans phosphatase genes, was analysed in transgenic C. elegans. The present results suggest that there is a significant degree of conservation between O. dentatum and C. elegans in the features and function of the serine/threonine protein phosphatase characterised, which should have implications for detailed investigations into molecular reproductive processes of some parasitic nematodes.
Exploring the Fasciola hepatica tegument proteome
Publisher: Elsevier BV
Date: 11-2011
DOI: 10.1016/J.IJPARA.2011.08.003
Abstract: The surface tegument of the liver fluke Fasciola hepatica is a syncytial cytoplasmic layer bounded externally by a plasma membrane and covered by a glycocalyx, which constitutes the interface between the parasite and its ruminant host. The tegument's interaction with the immune system during the fluke's protracted migration from the gut lumen through the peritoneal cavity and liver parenchyma to the lumen of the bile duct, plays a key role in the fluke's establishment or elimination. However, little is known about proteins of the tegument surface or its secretions. We applied techniques developed for the blood fluke, Schistosoma mansoni, to enrich a tegument surface membrane preparation and analyse its composition by tandem mass spectrometry using new transcript databases for F. hepatica. We increased the membrane and secretory pathway components of the final preparation to ∼30%, whilst eliminating contaminating proteases. We identified a series of proteins or transcripts shared with the schistosome tegument including annexins, a tetraspanin, carbonic anhydrase and an orthologue of a host protein (CD59) that inhibits complement fixation. Unique to F. hepatica, we also found proteins with lectin, cubulin and von Willebrand factor domains plus 10 proteins with leader sequences or transmembrane helices. Many of these surface proteins are potential vaccine candidates. We were h ered in collecting tegument secretions by the propensity of liver flukes, unlike blood flukes, to vomit their gut contents. We analysed both the 'vomitus' and a second supernatant released from haematin-depleted flukes. We identified many proteases, some novel, as well as a second protein with a von Willebrand factor domain. This study demonstrates that components of the tegumental surface of F. hepatica can be defined using proteomic approaches, but also indicates the need to prevent vomiting if tegument secretions are to be characterised.
DEMoS: A Deep Learning-based Ensemble Approach for Predicting the Molecular Subtypes of Gastric Adenocarcinomas from Histopathological Images.
Publisher: Oxford University Press (OUP)
Date: 08-07-2022
DOI: 10.1093/BIOINFORMATICS/BTAC456
Abstract: The molecular subtyping of gastric cancer (adenocarcinoma) into four main subtypes based on integrated multiomics profiles, as proposed by The Cancer Genome Atlas (TCGA) initiative, represents an effective strategy for patient stratification. However, this approach requires the use of multiple technological platforms, and is quite expensive and time-consuming to perform. A computational approach that uses histopathological image data to infer molecular subtypes could be a practical, cost- and time-efficient complementary tool for prognostic and clinical management purposes. Here, we propose a deep learning ensemble approach (called DEMoS) capable of predicting the four recognized molecular subtypes of gastric cancer directly from histopathological images. DEMoS achieved tile-level area under the receiver-operating characteristic curve (AUROC) values of 0.785, 0.668, 0.762 and 0.811 for the prediction of these four subtypes of gastric cancer [i.e. (i) Epstein–Barr (EBV)-infected, (ii) microsatellite instability (MSI), (iii) genomically stable (GS) and (iv) chromosomally unstable tumors (CIN)] using an independent test dataset, respectively. At the patient-level, it achieved AUROC values of 0.897, 0.764, 0.890 and 0.898, respectively. Thus, these four subtypes are well-predicted by DEMoS. Benchmarking experiments further suggest that DEMoS is able to achieve an improved classification performance for image-based subtyping and prevent model overfitting. This study highlights the feasibility of using a deep learning ensemble-based method to rapidly and reliably subtype gastric cancer (adenocarcinoma) solely using features from histopathological images. All whole slide images used in this study was collected from the TCGA database. This study builds upon our previously published HEAL framework, with related documentation and tutorials available at heal.erc.monash.edu.au. The source code and related models are freely accessible at github.com/Docurdt/DEMoS.git. Supplementary data are available at Bioinformatics online.
Vaccinomics for the major blood feeding helminths of humans
Publisher: Mary Ann Liebert Inc
Date: 09-2011
Abstract: Approximately one billion people are infected with hookworms and/or blood flukes (schistosomes) in developing countries. These two parasites are responsible for more disability adjusted life years lost than most other neglected tropical diseases (NTDs), and together, are second only to malaria. Although anthelmintic drugs are effective and widely available, they do not protect against reinfection, resistant parasites are likely to emerge, and mass drug administration programs are unsustainable. Therefore, there is a pressing need for the development of vaccines against these parasites. In recent years, there have been major advances in our understanding of hookworms and schistosomes at the molecular level through the use of "omics" technologies. The secretomes of these parasites have been characterized using transcriptomics, genomics, proteomics, and newly developed gene manipulation and silencing techniques, and the proteins of interest are now the target of novel antigen discovery approaches, notably immunomics. This research has resulted in the discovery, development, and early stage clinical trials of subunit vaccines against hookworms and schistosomes.
Cryptosporidium: Current State of Genomics and Systems Biological Research
Publisher: Springer Vienna
Date: 14-09-2013
Transcription profiles for two key gender-specific gene families in Oesophagostomum dentatum during development in vivo and in vitro
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.MEEGID.2011.10.026
Abstract: In strongylid roundworms, such as Oesophagostomum dentatum (porcine nodule worm), some sex-specific genes are likely to be associated with parasite maturation, development and reproduction. In this study, an analysis of transcription of the two sex-specific genes (vit and msp) encoding vitellogenin and major sperm protein of O. dentatum, respectively, revealed that adult females transcribed vit and adult males msp at high levels, in contrast to immature larval stages and pre-adult worms from in vitro cultures for which no transcription of vit or msp was detected. The analysis showed that neither presence nor absence of the heterologous sex, nor the duration of infection, was central to vit or msp transcription. In small or "virgin" adults, no or only low-level transcription of vit and msp was detectable. We hypothesize that the transcription of the sex-specific genes is linked to endogenous factors, such as size, maturation of the reproductive organs and/or fitness of the worms, and not to exogenous influences. The maturation of worms appears to be linked, to some extent, to the expression of the genes studied herein.
Detection of sequence variation in parasite ribosomal DNA by electrophoresis in agarose gels supplemented with a DNA‐intercalating agent
Publisher: Wiley
Date: 05-1998
Abstract: This study evaluated the use of a commercially available DNA intercalating agent (Resolver Gold) in agarose gels for the direct detection of sequence variation in ribosomal DNA (rDNA). This agent binds preferentially to AT sequence motifs in DNA. Regions of nuclear rDNA, known to provide genetic markers for the identification of species of parasitic ascarid nematodes (order Ascaridida), were lified by polymerase chain reaction (PCR) and subjected to electrophoresis in standard agarose gels versus gels supplemented with Resolver Gold. In idual taxa examined could not be distinguished reliably based on the size of their licons in standard agarose gels, whereas they could be readily delineated based on mobility using Resolver Gold-supplemented gels. The latter was achieved because of differences (approximately 0.1-8.2%) in the AT content of the fragments among different taxa, which were associated with significant interspecific differences (approximately 11-39%) in the rDNA sequences employed. There was a tendency for fragments with higher AT content to migrate slower in supplemented agarose gels compared with those of lower AT content. The results indicate the usefulness of this electrophoretic approach to rapidly screen for sequence variability within or among PCR- lified rDNA fragments of similar sizes but differing AT contents. Although evaluated on rDNA of parasites, the approach has potential to be applied to a range of genes of different groups of infectious organisms.
Toward Understanding the Functional Role of Ss-riok-1, a RIO Protein Kinase-Encoding Gene of Strongyloides stercoralis
Publisher: Public Library of Science (PLoS)
Date: 07-08-2014
Exploring features and function of Ss-riok-3, an enigmatic kinase gene from Strongyloides stercoralis
Publisher: Springer Science and Business Media LLC
Date: 12-2014
Genetic characterization of Cryptosporidium parvum from calves by mutation scanning and targeted sequencing - zoonotic implications.
Publisher: Wiley
Date: 08-2009
Abstract: This study explored the genetic make-up of Cryptosporidium in fecal s les from 268 in idual calves on pasture-based dairy farms in three regions of Victoria, Australia. An integrated approach, using PCR-coupled single-strand conformation polymorphism, targeted sequencing and phylogenetic analysis, was employed to classify the genetic variants (i.e. genotypes and subgenotypes) of Cryptosporidium parvum present in 124 (46.3%) s les and to infer their zoonotic potential. Genotypic and subgenotypic classification was achieved using a portion of the 60 kDa glycoprotein gene (designated pgp60) specific identity was verified using a region within the small subunit of the nuclear ribosomal RNA (pSSU). Twelve sequence types representing ten distinct subgenotypes were defined within genotype IIa, namely IIaA16G3R1 (n=7), IIaA17G2R1 (1), IIaA18G2R1a (2), IIaA18G2R1b (1), IIaA18G4R1 (1), IIaA19G3R1a (80), IIaA19G3R1b (1), IIaA20G2R1 (9), IIaA20G3R1 (1), IIaA20G4R1 (9), IIaA21G3R1 (1) and IIaA23G3R1 (9), of which IIaA18G2R1b, IIaA18G4R1 and IIaA19G3R1b are new records. All of the subgenotypes, except IIaA16G3R1, IIaA18G4R1 and IIaA20G4R1, have been detected previously in humans and are thus considered to be of zoonotic relevance. (Nucleotide sequences reported in this paper are available in the GenBank database under accession numbers FJ825018-FJ825029).
Single‐strand conformation polymorphism (SSCP)‐based mutation scanning approaches to fingerprint sequence variation in ribosomal DNA of ascaridoid nematodes
Publisher: Wiley
Date: 06-1998
Abstract: In this study, we assessed single‐strand conformation polymorphism (SSCP)‐based approaches for their capacity to fingerprint sequence variation in ribosomal DNA (rDNA) of ascaridoid nematodes of veterinary and/or human health significance. The second internal transcribed spacer region (ITS‐2) of rDNA was utilised as the target region because it is known to provide species‐specific markers for this group of parasites. ITS‐2 was lified by PCR from genomic DNA derived from in idual parasites and subjected to analysis. Direct SSCP analysis of licons from seven taxa ( Toxocara vitulorum, Toxocara cati, Toxocara canis, Toxascaris leonina, Baylisascaris procyonis, Ascaris suum and Parascaris equorum ) showed that the single‐strand (ss) ITS‐2 patterns produced allowed their unequivocal identification to species. While no variation in SSCP patterns was detected in the ITS‐2 within four species for which multiple s les were available, the method allowed the direct display of four distinct sequence types of ITS‐2 among in idual worms of T. cati. Comparison of SSCP/sequencing with the methods of dideoxy fingerprinting (ddF) and restriction endonuclease fingerprinting (REF) revealed that also ddF allowed the definition of the four sequence types, whereas REF displayed three of four. The findings indicate the usefulness of the SSCP‐based approaches for the identification of ascaridoid nematodes to species, the direct display of sequence variation in rDNA and the detection of population variation. The ability to fingerprint microheterogeneity in ITS‐2 rDNA using such approaches also has implications for studying fundamental aspects relating to mutational change in rDNA.
Redescription of Zoniolaimus mawsonae Beveridge, 1983 (Nematoda: Strongyloidea) and the description of Z. latebrosus n. sp. from the red kangaroo Macropus rufus (Marsupialia: Macropodidae) based on morphological and molecular data.
Publisher: Springer Science and Business Media LLC
Date: 02-2002
Abstract: This study shows that the description of Z. mawsonae given by Beveridge (1983) represented a composite of two species. Hence, Z. mawsonae Beveridge, 1983 is re-described and a new species, Z. latebrosus, is described. Males of the two species differ in the lengths of their spicules (0.94-1.23 mm in Z. mawsonae compared with 1.53-1.95 mm in Z. latebrosus) and in several characteristics of the bursa and genital cone. Females of the two species can be identified based on the shape of the posterior end of the body, that of Z. mawsonae being markedly swollen. Molecular data, obtained from single strand conformation polymorphism (SSCP) analysis and DNA sequencing of the second internal transcribed spacer of ribosomal DNA, provided additional support for the separation of the two species.
Phylogenetic relationships of species within the tribe Labiostrongylinea (Nematoda: Cloacinidae) from Australian marsupials based on ribosomal DNA spacer sequence data.
Publisher: Elsevier BV
Date: 12-2011
DOI: 10.1016/J.PARINT.2011.06.012
Abstract: Parasitic nematodes of the tribe Labiostrongylinea (Family Cloacinidae) occur in the stomachs of a wide variety of potoroid and macropodid marsupials in Australia, Papua Indonesia and Papua New Guinea. The aim of the present study was to infer the evolutionary relationships of the five genera of labiostrongyline nematodes that occur in Australian potoroids and macropodids using sequence data of the nuclear first and second internal transcribed spacers of ribosomal DNA. The phylogenetic analyses resulted in the separation of the Labiostrongylinea into two major groups reflecting coevolution between hosts and parasites. Two nematode species belonging to the genus Potorostrongylus formed a sister group to the remaining species of the Labiostrongylinea. This genus occurs exclusively in potoroid marsupials, which are considered to be basal to the macropodid marsupials. The second major group included species of Labiostrongylus, Labiosimplex, Labiomultiplex and Parazoniolaimus, all of which occur in macropodids. These species formed two distinct clades, one predominating in the host genera Thylogale and Onychogalea, and the second in the genus Macropus, which includes the more recent macropodids. However, there is also evidence of colonisation by both nematode clades of relatively unrelated hosts. In addition, genetic differences among in iduals of Lm. eugenii from geographically isolated populations of M. eugenii, and among Ls. longispicularis from different subspecies of M. robustus suggest the existence of sibling species that may have arisen by allopatric speciation. The broad coevolutionary relationship between the labiostrongyline nematodes and their marsupial hosts therefore represents a mixture of potential cospeciation and colonisation events.
Insights into SCP/TAPS Proteins of Liver Flukes Based on Large-Scale Bioinformatic Analyses of Sequence Datasets
Publisher: Public Library of Science (PLoS)
Date: 22-02-2012
High throughput LC-MS/MS-based proteomic analysis of excretory-secretory products from short-term in vitro culture of Haemonchus contortus
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.JPROT.2019.05.003
Abstract: Parasitic nematodes of humans, animals and plants have a major, adverse impact on global health and agricultural production worldwide. To cope with their surrounding environment in and the immune attack from the host, excretory-secretory (ES) proteins are released by nematodes to orchestrate or regulate parasite-host interactions. In the present study, we characterised the ES products from short-term (12 h) in vitro culture of different developmental stages/sexes of Haemonchus contortus (one of the most important parasitic nematodes of livestock animals worldwide) using a high throughput tandem mass-spectrometry, underpinned by the most recent genomic dataset. In total, 878 unique proteins from key developmental stages/sexes (third-stage and fourth-stage larvae, and female and male adults) were identified and quantified with high confidence. Bioinformatic analyses showed noteworthy ES protein alterations during the transition from the free-living to the parasitic phase, especially for proteins which are likely involved in nutrient digestion and acquisition as well as parasite-host interactions, such as proteolytic cascade-related peptidases, glycoside hydrolases, C-type lectins and sperm-coating protein/Tpx/antigen 5 athogenesis related-1/Sc7 (= SCP/TAPS) proteins. Our findings provide an avenue to better explore interactive processes between the host and this highly significant parasitic nematode, to underpin the search for novel drug and vaccine targets. SIGNIFICANCE: The present study represents a comprehensive proteomic analysis of the secretome of key developmental stages/sexes of H. contortus maintained in short-term in vitro culture. High throughput LC-MS/MS analysis of ES products allowed the identification of a large repertoire of proteins (secretome) and the establishment of a new proteomic database for H. contortus. The secretome of H. contortus undergoes substantial changes during the nematode's transition from free-living to parasitic stages, suggesting a constant adaptation to different environments outside of and within the host animal. Understanding the host-parasite relationship at the molecular level could assist significantly in the development of intervention strategies (i.e. novel drugs and vaccines) against H. contortus and related nematodes.
Construction of gender-enriched cDNA archives for adult Oesophagostomum dentatum by suppressive-subtractive hybridization and a microarray analysis of expressed sequence tags
Publisher: Cambridge University Press (CUP)
Date: 23-01-2006
An appraisal of natural products active against parasitic nematodes of animals
Publisher: Springer Science and Business Media LLC
Date: 17-06-2019
Resurrection and redescription of Globocephaloides wallabiae Johnston et Mawson, 1939 (Nematoda, Trichostrongyloidea) from macropodid marsupials in north-eastern Australia
Publisher: Walter de Gruyter GmbH
Date: 2010
DOI: 10.2478/S11686-010-0023-5
Abstract: Globocephaloides wallabiae Johnston et Mawson, 1939, is resurrected as a valid species and is redescribed. G. wallabiae is distinguished from its closest congener, G. macropodis Yorke et Maplestone, 1926, by the spicules (length and tip) and pattern of the bursal rays. G. wallabiae occurs commonly in Macropus dorsalis (Gray, 1837) in north-eastern Queensland, but is also present in Petrogale mareeba Eldridge et Close, 1992 and P. assimilis Ramsay, 1877. By contrast, G. macropodis is found commonly in M. agilis (Gould, 1842) and P. persephone Maynes, 1982 in the Northern Territory and north-eastern Queensland, and occurs incidentally in other hosts, probably as a result of host-switching ((Aepyprymnus rufescens (Gray, 1837), P. brachyotis (Gould, 1841), P. inornata Gould, 1842, M. dorsalis, M. parryi Bennett, 1835, M. giganteus Shaw, 1790 and Largochestes conspicillatus Gould, 1842)). This morphological study, with additional host and geographical distributional data, provides support for the resurrection of the species.
Arylpyrrole and fipronil analogues that inhibit the motility and/or development of Haemonchus contortus in vitro
Publisher: Elsevier BV
Date: 12-2018
IDENTIFICATION AND CHARACTERIZATION OF MYOPHILIN, A MUSCLE-SPECIFIC ANTIGEN OF ECHINOCOCCUS-GRANULOSUS
Publisher: Elsevier BV
Date: 03-1995
DOI: 10.1016/0166-6851(95)00020-2
Abstract: A muscle-specific gene of Echinococcus granulosus has been identified and characterized. A lambda gt11 clone (10P1), containing an incomplete copy of the gene, was originally isolated from a larval E. granulosus cDNA library by serum antibodies from dogs infected with the parasite. The full-length cDNA sequence was obtained by PCR lification of cDNA from an adult E. granulosus lambda gt22A library. Southern blot analysis indicated the presence of the gene as a single copy in the genome of E. granulosus and also detected homologous genes in genomic DNA of E. multilocularis and Taenia saginata. The 21.2-kDa protein deduced from the complete cDNA sequence contains two regions of 12 amino acids with similarity to the EF-hand motif of calcium binding proteins. Antibodies raised against the purified 10P1-GST fusion protein detected a 22-kDa antigen in the E. granulosus developmental stages examined. Immunoelectron microscopy localized the native protein in the muscle of the parasite. The amino-acid sequence of the E. granulosus protein shows significant homology to the muscle proteins mp20 of Drosophila melanogaster, chicken SM22 alpha and mammalian calponin, and also to the neuronal protein NP25 of rats. A conserved carboxy-terminal motif of 17 amino acids is present in all the homologous proteins and is proposed to be the characteristic feature of a novel protein family. The term myophilin is proposed for the E. granulosus protein due to its localization and homology to other muscle proteins.
Practical and low cost whole-organism motility assay: A step-by-step protocol
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.MCP.2015.08.005
Abstract: Here, we provide a step-by-step protocol for a practical and low cost whole-organism assay for the screening of chemical compounds for activity against parasitic worms. This assay has considerable advantages over conventional methods, mainly in relation to ease of use, throughput, time and cost. It is readily suited to the screening of hundreds to thousands of compounds for subsequent hit-to-lead optimisation, and should be applicable to many different parasites and other organisms commensurate with the size of wells in the microtiter plates used for phenotypic screening.
Correction: Investigating the Role of RIO Protein Kinases in Caenorhabditis elegans
Publisher: Public Library of Science (PLoS)
Date: 18-05-2016
Identification of Fromiamycalin and Halaminol A from Australian Marine Sponge Extracts with Anthelmintic Activity against Haemonchus contortus
Publisher: MDPI AG
Date: 23-10-2019
DOI: 10.3390/MD17110598
Abstract: There is an urgent need to discover and develop new anthelmintics for the treatment of parasitic nematodes of veterinary importance to circumvent challenges linked to drug resistant parasites. Being one of the most erse natural ecosystems, the marine environment represents a rich resource of novel chemical entities. This study investigated 2000 extracts from marine invertebrates, collected from Australian waters, for anthelmintic activity. Using a well-established in vitro bioassay, these extracts were screened for nematocidal activity against Haemonchus contortus — a socioeconomically important parasitic nematode of livestock animals. Extracts (designated Mu-1, Ha-1 and Ha-2) from two marine sponges (Monanchora unguiculata and Haliclona sp.) each significantly affected larvae of H. contortus. In idual extracts displayed a dose-dependent inhibition of both the motility of exsheathed third-stage larvae (xL3s) and the development of xL3s to fourth-stage larvae (L4s). Active fractions in each of the three extracts were identified using bioassay-guided fractionation. From the active fractions from Monanchora unguiculata, a known pentacyclic guanidine alkaloid, fromiamycalin (1), was purified. This alkaloid was shown to be a moderately potent inhibitor of L4 development (half-maximum inhibitory concentration (IC50) = 26.6 ± 0.74 µM) and L4 motility (IC50 = 39.4 ± 4.83 µM), although it had a relatively low potency at inhibiting of xL3 motility (IC50 ≥ 100 µM). Investigation of the active fractions from the two Haliclona collections led to identification of a mixture of amino alcohol lipids, and, subsequently, a known natural product halaminol A (5). Anthelmintic profiling showed that 5 had limited potency at inhibiting larval development and motility. These data indicate that fromiamycalin, other related pentacyclic guanidine alkaloids and/or halaminols could have potential as anthelmintics following future medicinal chemistry efforts.
Long-read sequencing reveals a 4.4 kb tandem repeat region in the mitogenome of Echinococcus granulosus (sensu stricto) genotype G1
Publisher: Springer Science and Business Media LLC
Date: 16-05-2019
Single-strand conformation polymorphism (SSCP) for the analysis of genetic variation
Publisher: Springer Science and Business Media LLC
Date: 12-2007
Abstract: The accurate analysis of genetic variation has major implications in many areas of biomedical research, including the identification of infectious agents (such as parasites), the diagnosis of infections, and the detection of unknown or known disease-causing mutations. Mutation scanning methods, including PCR-coupled single-strand conformation polymorphism (SSCP), have significant advantages over many other nucleic acid techniques for the accurate analysis of allelic and mutational sequence variation. The present protocol describes the SSCP method of analysis, including all steps from the small-scale isolation of genomic DNA and PCR lification of target sequences, through to the gel-based separation of licons and scanning for mutations by SSCP (either by the analysis of radiolabeled licons in mutation detection enhancement (MDE) gels or by non-isotopic SSCP using precast GMA gels). The subsequent sequence analysis of polymorphic bands isolated from gels is also detailed. The SSCP protocol can readily detect point mutations for licon sizes of up to 450-500 bp, and usually takes 1-2 days to carry out. This user-friendly, low-cost, potentially high-throughput platform has demonstrated the utility to study a wide range of pathogens and diseases, and has the potential to be applied to any gene of any organism.
Mutation scanning-coupled analysis of haplotypic variability in mitochondrial DNA regions reveals low gene flow between human and porcineAscaris in endemic regions of China
Publisher: Wiley
Date: 11-2005
Abstract: Haplotypic variation within and among the Ascaris populations representing six provinces in China was investigated. Mitochondrial DNA regions in the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes were lified by PCR from total genomic DNA s les (n > 720) from Ascaris in iduals from humans and pigs, and subjected to mutation scanning and subsequent selective sequencing. For the cox1, ten different electrophoretic profiles were recorded for human Ascaris, and the same number for pig Ascaris, one of them being common to both host species. For the nad1, 11 different profiles were detected for human Ascaris, and 15 for pig Ascaris. Having defined all haplotypes (20 for pcox1 and 26 for pnad1) by sequencing, their frequencies were estimated in each of the two host species and each of the six provinces. For each mitochondrial region, the frequency of the different haplotypes varied considerably, depending on host species and geographical origin. Analysis of the sequence data (representing all haplotypes for each mitochondrial locus) by F-statistics indicated restricted gene flow between human Ascaris and pig Ascaris, and supported the conclusions from previous molecular epidemiological investigations that pigs are not a significant source of Ascaris infection in humans in endemic regions.
Time-Dependent Transcriptional Changes in Axenic Giardia duodenalis Trophozoites
Publisher: Public Library of Science (PLoS)
Date: 04-12-2015
Multiplexed Tandem PCR (MT-PCR) Assay Using the Major Piroplasm Surface Protein Gene for the Diagnosis of Theileria orientalis Infection in Cattle
Publisher: American Society for Microbiology
Date: 03-2018
DOI: 10.1128/JCM.01661-17
Bioinformatic analysis of abundant, gender-enriched transcripts of adult Ascaris suum (Nematoda) using a semi-automated workflow platform
Publisher: Elsevier BV
Date: 10-2009
DOI: 10.1016/J.MCP.2009.03.003
Abstract: Expressed sequence tag (EST) data representing transcripts with a high level of differential hybridization in suppressive-subtractive hybridization (SSH)-based microarray analysis between adult female and male Ascaris suum were subjected to detailed bioinformatic analysis. A total of 361 ESTs clustered into 209 sequences, of which 52 and 157 represented transcripts that were enriched in female and male A. suum, respectively. Thirty (57.7%) of the 'female' subset of 52 sequences had orthologues/homologues in other parasitic nematodes and/or Caenorhabditis elegans, 13 (25%) exclusively in other parasitic nematodes and nine (17.3%) had no match in any other organism for which sequence data are currently available the C. elegans orthologues encoded molecules involved in reproduction as well as embryonic and gamete development, such as vitellogenins and chitin-binding proteins. Of the 'male' subset of 157 sequences, 73 (46.5%) had orthologues/homologues in other parasitic nematodes and/or C. elegans, 57 (37.5%) in other parasitic nematodes only, and 22 (14.5%) had no significant similarity match in any other organism the C. elegans orthologues encoded predominantly major sperm proteins (MSPs), kinases and phosphatases, actins, myosins and an Ancylostoma secreted protein-like molecule. The findings of the present study should support further genomic investigations of A. suum.
Genetic markers for closely-related parasitic nematodes
Publisher: Elsevier BV
Date: 10-1995
DOI: 10.1016/S0890-8508(95)91588-5
Abstract: Seven species of closely-related nematode parasite (Trichostrongylus axei, T. colubriformis, T. probolurus, T. retortaeformis, T. rugatus, T. vitrinus and T. tenuis) were characterized using a polymerase chain reaction-linked restriction fragment length polymorphism technique (PCR-RFLP). The rDNA region spanning the first and second internal transcribed spacers as well as the 5.8S rDNA gene (ITS+) was lified from isolates of each of the seven species, digested separately with six restriction endonucleases (Dra I, Hinf I, Rsa I, Vsp I, Nla III and Tsp 509 I) and the fragments separated by agarose gel electrophoresis. PCR-RFLP of ITS+ produced characteristic patterns for each Trichostrongylus species examined. No variation in RFLP patterns was observed among different isolates for species where multiple isolates were examined. The present study demonstrates that the ITS+ provides genetic markers for the species identification of closely-related parasitic nematodes, and indicates the usefulness of these markers for diagnostic purposes, and epidemiologic and molecular-systematic studies on parasites and other eukaryotic organisms.
Defining the Schistosoma haematobium kinome enables the prediction of essential kinases as anti-schistosome drug targets
Publisher: Springer Science and Business Media LLC
Date: 04-12-2015
DOI: 10.1038/SREP17759
Abstract: The blood fluke Schistosoma haematobium causes urogenital schistosomiasis, a neglected tropical disease (NTD) that affects more than 110 million people. Treating this disease by targeted or mass administration with a single chemical, praziquantel, carries the risk that drug resistance will develop in this pathogen. Therefore, there is an imperative to search for new drug targets in S. haematobium and other schistosomes. In this regard, protein kinases have potential, given their essential roles in biological processes and as targets for drugs already approved by the US Food and Drug Administration (FDA) for use in humans. In this context, we defined here the kinome of S. haematobium using a refined bioinformatic pipeline. We classified, curated and annotated predicted kinases and assessed the developmental transcription profiles of kinase genes. Then, we prioritised a panel of kinases as potential drug targets and inferred chemicals that bind to them using an integrated bioinformatic pipeline. Most kinases of S. haematobium are very similar to those of its congener, S. mansoni , offering the prospect of designing chemicals that kill both species. Overall, this study provides a global insight into the kinome of S. haematobium and should assist the repurposing or discovery of drugs against schistosomiasis.
Toxocara malaysiensis infection in domestic cats in Vietnam — An emerging zoonotic issue?
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.MEEGID.2015.11.009
Abstract: Toxocara canis of canids is a parasitic nematode (ascaridoid) that infects humans and other hosts, causing different forms of toxocariasis. This species of Toxocara appears to be the most important cause of human disease, likely followed by Toxocara cati from felids. Although some studies from Malaysia and China have shown that cats can harbor another congener, T. malaysiensis, no information is available about this parasite for other countries. Moreover, the zoonotic potential of this parasite is unknown at this point. In the present study, we conducted the first investigation of domestic dogs and cats for Toxocara in Vietnam using molecular tools. Toxocara malaysiensis was identified as a common ascaridoid of domestic cats (in the absence of T. cati), and T. canis was commonly found in dogs. Together with findings from previous studies, the present results emphasize the need to explore the significance and zoonotic potential of T. malaysiensis in Vietnam and other countries where this parasite is endemic and prevalent in cats.
Genetic analysis of Trichinella populations by ‘cold’ single-strand conformation polymorphism analysis
Publisher: Elsevier BV
Date: 09-2005
DOI: 10.1016/J.VETPAR.2005.05.021
Abstract: A non-isotopic single-strand conformation polymorphism ('cold' SSCP) technique has been assessed for the analysis of sequence variability in the expansion segment 5 (ES5) of domain IV and the D3 domain of nuclear ribosomal DNA within and/or among isolates and in idual muscle (first-stage) larvae representing all currently recognized species/genotypes of Trichinella. Data are consistent with the ability of cold SSCP to identify intra-specific as well as inter-specific variability among Trichinella genotypes. The cold SSCP approach should be applicable to a range of other genetic markers for comparative studies of Trichinella populations globally.
Common workflow language (CWL)-based software pipeline for de novo genome assembly from long- and short-read data
Publisher: Oxford University Press (OUP)
Date: 03-2019
Major prospects for exploring canine vector borne diseases and novel intervention methods using 'omic technologies
Publisher: Springer Science and Business Media LLC
Date: 13-04-2011
Structural and functional characterisation of the fork head transcription factor-encoding gene, Hc-daf-16, from the parasitic nematode Haemonchus contortus (Strongylida)
Publisher: Elsevier BV
Date: 03-2010
Understanding Haemonchus contortus Better Through Genomics and Transcriptomics
Publisher: Elsevier
Date: 2016
DOI: 10.1016/BS.APAR.2016.02.015
Abstract: Parasitic roundworms (nematodes) cause substantial mortality and morbidity in animals globally. The barber's pole worm, Haemonchus contortus, is one of the most economically significant parasitic nematodes of small ruminants worldwide. Although this and related nematodes can be controlled relatively well using anthelmintics, resistance against most drugs in common use has become a major problem. Until recently, almost nothing was known about the molecular biology of H. contortus on a global scale. This chapter gives a brief background on H. contortus and haemonchosis, immune responses, vaccine research, chemotherapeutics and current problems associated with drug resistance. It also describes progress in transcriptomics before the availability of H. contortus genomes and the challenges associated with such work. It then reviews major progress on the two draft genomes and developmental transcriptomes of H. contortus, and summarizes their implications for the molecular biology of this worm in both the free-living and the parasitic stages of its life cycle. The chapter concludes by considering how genomics and transcriptomics can accelerate research on Haemonchus and related parasites, and can enable the development of new interventions against haemonchosis.
Genetic markers in ribosomal DNA for hookworm identification
Publisher: Elsevier BV
Date: 09-1996
DOI: 10.1016/S0001-706X(96)00015-0
Abstract: Polymerase chain reaction-linked restriction fragment length polymorphism (PCR-RFLP) analysis of ribosomal (r) DNA was conducted on Uncinaria stenocephala, Ancylostoma caninum, A. tubaeforme and A. ceylanicum. The rDNA region spanning the first and second internal transcribed spacers (ITS1 and ITS2) plus the 5.8S (ITS+) gene was lified by PCR from each of the species, digested separately with 9 restriction endonucleases and the fragments separated by agarose gel electrophoresis. Characteristic PCR-RFLP patterns were produced for each morphologically defined species using some of the endonucleases. The present study demonstrated that the ITS+ provides genetic markers for the delineation of each species examined and suggests that this region of rDNA will be useful for the identification of other hookworms from a range of hosts. The results are likely to have important implications for studying the genetic structure of hookworm populations, the systematics and the epidemiology of hookworm infections.
Prospects for exploring molecular developmental processes in Haemonchus contortus
Publisher: Elsevier BV
Date: 07-2006
DOI: 10.1016/J.IJPARA.2006.04.007
Abstract: Haemonchus contortus of small ruminants is a parasitic nematode of major socio-economic importance world-wide. While there is considerable knowledge of the morphological changes which take place during the life cycle of H. contortus, very little is understood about the molecular and biochemical processes which govern developmental changes in the parasite. Recent technological advances and the imminent genomic sequence for H. contortus provide unique opportunities to investigate the molecular basis of such processes in parasitic nematodes. This article reviews molecular and biochemical aspects of development in H. contortus, reports on some recent progress on signal transduction molecules in this parasite and emphasises the opportunities that new technologies and the free-living nematode, Caenorhabditis elegans, offer for investigating developmental aspects in H. contortus and related strongylid nematodes, also in relation to developing novel approaches for control.
Spirometra erinacei / S. erinaceieuropaei in a feral cat in Manawatu with chronic intermittent diarrhoea
Publisher: Informa UK Limited
Date: 10-2005
DOI: 10.1080/00480169.2005.36573
Abstract: A feral cat captured in the Manawatu region of New Zealand was treated for worms and fleas, and kept confined in a metabolic cage. It showed good appetite and weight gain but had intermittent watery, yellow diarrhoea. Clinical examination under sedation was unremarkable and routine blood tests showed no significant abnormalities. The cat was negative for feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). Different canned cat foods did not alter the course of the diarrhoea, and the cat was euthanised 6 months after capture. At necropsy, two sections of adult Spirometra tapeworms were found in the jejunum and typical Spirometra eggs were found in colonic contents. Molecular identification of the parasite was undertaken, using the cytochrome-c oxidase subunit-1 gene (cox1) sequence. Chronic intermittent diarrhoea associated with Spirometra erinacei / S. erinaceieuropaei infection. Spirometra has not been reported in New Zealand before but has been associated with gastrointestinal disease in cats in other parts of the world. It requires species targeted treatment to be eliminated effectively, and is zoonotic. Diagnosis could be difficult for clinicians who are not familiar with the parasite and its life cycle.
Mitochondrial genome of Bulinus truncatus (Gastropoda: Lymnaeoidea): Implications for snail systematics and schistosome epidemiology
Publisher: Elsevier BV
Date: 2021
Anthelmintic activity of selected ethno-medicinal plant extracts on parasitic stages of Haemonchus contortus
Publisher: Springer Science and Business Media LLC
Date: 04-2016
Helminth Microbiomes – A Hidden Treasure Trove?
Publisher: Elsevier BV
Date: 2019
Abstract: There is increasing attention on the complex interactions occurring between gastrointestinal parasitic helminths and the microbial flora (microbiota) inhabiting the host gut. However, little is known about the occurrence, structure, and function of microbial populations residing within parasite organs and tissues. In this article, we argue that an in-depth understanding of the interplay between parasites and their microbiomes may significantly enhance current knowledge of parasite biology and physiology, and may lead to the discovery of entirely novel, anthelmintic-independent interventions against parasites and parasitic diseases.
A transcriptomic analysis of the adult stage of the bovine lungworm, Dictyocaulus viviparus
Publisher: Springer Science and Business Media LLC
Date: 2007
Establishment of a robotic, high-throughput platform for the specific diagnosis of gastrointestinal nematode infections in sheep
Publisher: Elsevier BV
Date: 12-2012
DOI: 10.1016/J.IJPARA.2012.10.005
Abstract: The accurate diagnosis of strongylid nematode infections is central to investigating their epidemiology and for parasite control. To overcome major limitations in sensitivity or specificity of traditional methods, including faecal egg count (FEC) and/or larval culture (LC), we evaluated and established a semi-automated, high throughput multiplexed-tandem PCR (MT-PCR) platform for the diagnosis of gastrointestinal strongylid nematode infections in sheep, and established its diagnostic sensitivity (100%) and specificity (87.5%) based on the testing of 100 faecal DNA s les from helminth-free sheep and 30 s les from sheep with infections confirmed by necropsy. Subsequently, the platform was employed to test 219 faecal s les from sheep with naturally acquired infections from various geographical localities within Australia and the results compared with those from conventional LC using 139 of the 219 s les. The results obtained using both MT-PCR and LC correlated significantly for most nematodes examined, but revealed that Oesophagostomum venulosum and Chabertia ovina (parasites of the large intestine) were significantly under-represented in the LC results. The results showed that Trichostrongylus spp. (87%), Teladorsagia circumcincta (80%) and Haemonchus contortus (67%) had the highest prevalences, followed by O. venulosum (51%) and C. ovina (12%). The molecular-diagnostic platform established can be used for species- or genus-specific diagnosis of patent nematode infections within 24h (compared with 7-10 days for LC), and is a sensitive and cost effective tool for routine application in research and service laboratories.
Sequence-based Analysis of Enzymatically Amplified DNA Fragments by Mutation Detection Techniques
Publisher: Elsevier BV
Date: 11-1999
DOI: 10.1016/S0169-4758(99)01536-7
Abstract: The accurate analysis of molecular variation is important in a range of disciplines of parasitology. Although conventional DNA techniques have overcome some of the limitations of traditional approaches, some can be relatively expensive and/or cumbersome to use when large s le sizes require analysis, and some cannot accurately resolve or define nucleotide variation. Using selected ex les of applications to parasites, Robin Gasser and Xingquan Zhu discuss some PCR-based mutation detection techniques and their advantages over conventional analytical methods.
Dafachronic acid promotes larval development in Haemonchus contortus by modulating dauer signalling and lipid metabolism
Publisher: Public Library of Science (PLoS)
Date: 23-07-2019
Oesophagostomum bifurcum in non‐human primates is not a potential reservoir for human infection in Ghana
Publisher: Wiley
Date: 12-2005
DOI: 10.1111/J.1365-3156.2005.01527.X
Abstract: In northern Togo and Ghana, human infection with the parasitic nematode Oesophagostomum bifurcum is of major health importance. Elsewhere, oesophagostomiasis is considered a zoonotic infection, non-human primates being the natural host. We examined 349 faecal s les of the olive baboon, mona monkey and black and white colobus monkey from two geographically distinct areas in Ghana, outside the region endemic for O. bifurcum in humans. Using both microscopy and species-specific PCR, we found a high prevalence of O. bifurcum (75-99%) in olive baboons and mona monkeys. The majority of the test-positive faecal s les contained large numbers of larvae after copro-culture (>100). No O. bifurcum was detected in the faeces of the black and white colobus monkeys. Observational studies on the behaviour of the non-human primates, focusing on defecation, food consumption and the sharing of habitat with the local human population, indicated favourable conditions for zoonotic transmission. Given that no human infection with O. bifurcum has been reported from either study area, the present findings support the hypothesis that O. bifurcum from humans in the north of Ghana, and O. bifurcum from olive baboons and/or mona monkeys are distinct.
A suicide inhibitor of nematode trehalose-6-phosphate phosphatases
Publisher: Springer Science and Business Media LLC
Date: 07-11-2019
DOI: 10.1038/S41598-019-52593-9
Abstract: Protein-based drug discovery strategies have the distinct advantage of providing insights into the molecular mechanisms of chemical effectors. Currently, there are no known trehalose-6-phosphate phosphatase (TPP) inhibitors that possess reasonable inhibition constants and chemical scaffolds amenable to convenient modification. In the present study, we subjected recombinant TPPs to a two-tiered screening approach to evaluate several erse compound groups with respect to their potential as TPP inhibitors. From a total of 5452 compounds tested, N -(phenylthio)phthalimide was identified as an inhibitor of nematode TPPs with apparent K i values of 1.0 μM and 0.56 μM against the enzymes from the zoonotic roundworms Ancylostoma ceylanicum and Toxocara canis , respectively. Using site-directed mutagenesis, we demonstrate that this compound acts as a suicide inhibitor that conjugates a strictly conserved cysteine residue in the vicinity of the active site of nematode TPPs. The anthelmintic properties of N -(phenylthio)phthalimide were assessed in whole nematode assays using larvae of the ascaroids T. canis and T. cati , as well as the barber’s pole worm Haemonchus contortus . The compound was particularly effective against each of the ascaroids with an IC 50 value of 9.3 μM in the survival assay of T. cati larvae, whereas no bioactivity was observed against H. contortus .
Investigating a persistent coccidiosis problem on a commercial broiler–breeder farm utilising PCR-coupled capillary electrophoresis
Publisher: Springer Science and Business Media LLC
Date: 03-04-2007
DOI: 10.1007/S00436-007-0516-9
Abstract: In the present study, we utilised a polymerase-chain-reaction-coupled capillary electrophoresis (CE) approach to investigate the epidemiology of Eimeria species on a broiler-breeder farm in Victoria, Australia. The Eimeria populations of two flocks vaccinated against coccidiosis were followed over an 11-week period. All seven recognised Eimeria species of chickens were detected in both flocks. One flock suffered increased morbidity and mortality in its eighth week and had consistently higher Eimeria oocyst counts, species prevalences and rates of co-infections. Four Eimeria species included in the vaccine administered occurred at higher prevalences before the disease outbreak in the flock. Using the CE approach, two new, previously undescribed Eimeria genotypes were discovered in both chicken flocks, one of which dominated toward the end of the study period. The molecular approach proved versatile and capable of providing useful epidemiological data which could be used to investigate and interpret coccidiosis outbreaks.
Mitochondrial Genome Analyses Suggest Multiple Trichuris Species in Humans, Baboons, and Pigs from Different Geographical Regions
Publisher: Public Library of Science (PLoS)
Date: 14-09-2015
Analysis of genetic variability within Thelazia callipaeda (Nematoda: Thelazioidea) from Europe and Asia by sequencing and mutation scanning of the mitochondrial cytochrome c oxidase subunit 1 gene
Publisher: Elsevier BV
Date: 10-2005
DOI: 10.1016/J.MCP.2005.05.001
Abstract: This study investigated genetic variability within the 'eyeworm'Thelazia callipaeda (Nematoda: Thelazioidea) from Europe and Asia by polymerase chain reaction (PCR)-coupled sequencing and mutation scanning of the mitochondrial cytochrome c oxidase subunit 1 gene (cox 1). Eight different sequence variants of cox 1 (haplotypes) were determined for the 50 in idual adult specimens of T. callipaeda (from dogs, foxes or cats from Italy, Germany and the Netherlands and from dogs from China and Korea). Nucleotide variation (0.3--2%) was detected at 23 of 649 positions in the cox 1. Six of these positions were invariable among all 37 in iduals from Europe and among the 13 in iduals from Asia (irrespective of host origin) but differed (five G A and one C T changes) between Europe and Asia. PCR-based single-strand conformation polymorphism (SSCP) analysis of the most variable portion (v-cox 1) of the cox 1 was validated (for a subset of s les) as a tool to rapidly screen for genetic (haplotypic) variability. The results for the SSCP analysis and sequencing were concordant, indicating that the mutation scanning approach provides a useful tool for investigating the population genetics and molecular ecology of T. callipaeda.
Strongylus asini (Nematoda, Strongyloidea): Genetic relationships with other strongylus species determined by ribosomal DNA
Publisher: Elsevier BV
Date: 12-1996
DOI: 10.1016/S0020-7519(96)00136-1
Abstract: Genomic DNA was isolated from adult Strongylus asini collected from zebra. The second ribosomal transcribed spacer (ITS-2) was lified and sequenced using polymerase chain reaction (PCR) based techniques. The DNA sequence was compared with previously published data for 3 related Strongylus species. A PCR-linked restriction fragment length polymorphism method allowed the 4 species to be differentiated unequivocally. The ITS-2 sequence of S. asini was found to be more similar to those of S. edentatus (87.1%) and S. equinus (95.3%) than to that of S vulgaris (73.9%). This result confirms that S. Asini and S vulgaris represent separate species and supports the retention of the 4 species within 1 genus.
ESTExplorer: An expressed sequence tag (EST) assembly and annotation platform
Publisher: Oxford University Press (OUP)
Date: 08-05-2027
DOI: 10.1093/NAR/GKM378
Two benzimidazole resistance-associated SNPs in the isotype-1 β-tubulin gene predominate in Haemonchus contortus populations from eight regions in China
Publisher: Elsevier BV
Date: 12-2016
Molecular evidence for a cryptic species within the parasitic nematode Macroponema comani (Strongyloidea: Cloacininae)
Publisher: Elsevier BV
Date: 08-2012
DOI: 10.1016/J.MCP.2012.03.002
Abstract: Nematodes resembling Macroponema comani, a common parasite of eastern grey kangaroos, Macropus giganteus, in eastern Australia were collected from an unexpected host species, the northern wallaroo, Macropus robustus woodwardi, in the Northern Territory, representing a highly disjunct occurrence. Although these specimens showed no morphological differences when compared with Ma. comani from M. giganteus, sequencing of the first and second internal transcribed spacers ITS-1 and ITS-2 of the nuclear ribosomal DNA revealed seven base pair differences in each spacer region between the two taxa. These differences included a number of autapomorphies. Sequences from both taxa differed significantly from those of Ma. beveridgei, a common parasite of the common wallaroo, Macropus robustus robustus and the euro, M. robustus erubescens. Based on these findings, the specimens in M. r. woodwardi are considered to represent a crypic species.
Ascaris phylogeny based on multiple whole mtDNA genomes
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.MEEGID.2016.12.003
Abstract: Ascaris lumbricoides and A. suum are two parasitic nematodes infecting humans and pigs, respectively. There has been considerable debate as to whether Ascaris in the two hosts should be considered a single or two separate species. Previous studies identified at least three major clusters (A, B and C) of human and pig Ascaris based on partial cox1 sequences. In the present study, we selected major haplotypes from these different clusters to characterize their whole mitochondrial genomes for phylogenetic analysis. We also undertook coalescent simulations to investigate the evolutionary history of the different Ascaris haplotypes. The topology of the phylogenetic tree based on complete mitochondrial genomic sequences was found to be similar to partial cox1 sequencing, but the support at internal nodes was higher in the former. Coalescent simulations suggested the presence of at least two ergence events: the first one occurring early in the Neolithic period which resulted in a differentiated population of Ascaris in pigs (cluster C), the second occurring more recently (~900 generations ago), resulting in clusters A and B which might have been spread worldwide by human activities.
Genetic evidence for the existence of sibling species within Contracaecum rudolphii (Hartwich, 1964) and the validity of Contracaecum septentrionale (Kreis, 1955) (Nematoda: Anisakidae)
Publisher: Springer Science and Business Media LLC
Date: 06-2005
DOI: 10.1007/S00436-005-1366-Y
Abstract: Specimens of Contracaecum rudolphii sensu lato (s.l.) (Nematoda: Anisakidae) from Phalacrocorax carbo sinensis from northeastern and central Italy were characterised genetically and compared with those from Phalacrocorax aristotelis from Galician coasts, Spain (identified as C. rudolphii A by multilocus enzyme electrophoresis) and with specimens of C. septentrionale from Alca torda from the Galician coasts, Spain. The first (ITS-1) and second (ITS-2) internal transcribed spacers (ITS) of ribosomal DNA (rDNA) were lified by polymerase chain reaction (PCR) from in idual nematodes and the licons subjected to single-strand conformation polymorphism (SSCP) analysis and/or sequencing. For each ITS region, C. septentrionale specimens were distinct from those of C. rudolphii (s.l.) and C. rudolphii A based on SSCP profiles and ITS sequences. Some specimens of C. rudolphii (s.l.) had the same SSCP profiles and ITS sequences as C. rudolphii A, whereas the others had distinct SSCP profiles and ITS sequences and were suggested to represent C. rudolphii B based on host and geographical origins and genetic similarity to C. rudolphii A. While no length or nucleotide variation in the ITS-1 and ITS-2 sequences was detected within each taxon, nucleotide differences of 1.8-5.5% (ITS-1) and 5.1-12.2% (ITS-2) were detected among them. The results support the hypothesis that C. rudolphii represents a complex of at least two sibling species and provide support for the validity of C. septentrionale as a separate species. The definition of genetic markers in the ITS rDNA provides opportunities for investigating the life cycles, transmission patterns and ecology of the anisakid nematodes studied herein.
CAP protein superfamily members in Toxocara canis
Publisher: Springer Science and Business Media LLC
Date: 24-06-2016
Description and genetic characterisation of Hysterothylacium (Nematoda: Raphidascarididae) larvae parasitic in Australian marine fishes
Publisher: Elsevier BV
Date: 06-2013
DOI: 10.1016/J.PARINT.2012.10.001
Abstract: Nematodes belonging to the genus Hysterothylacium (family Raphidascarididae) infect various species of marine fish in both the larval and adult stages. Humans can be accidentally infected upon eating infected seafood. In spite of their importance, relatively little is known of their occurrence and systematics in Australia. An examination of various species of marine teleosts in Australian waters revealed a high prevalence of Hysterothylacium larval types. In the present study, seven previously undescribed Hysterothylacium larval morphotypes (V to VII and IX to XII) were discovered. In total we found 10 different morphotypes and we genetically characterised nine morphotypes identified. A morphological dichotomous identification key has been established to differentiate these morphotypes. Since some larvae of Hysterothylacium from marine fishes cannot be differentiated morphologically from other nematode larvae, such as Paraheterotyphlum, Heterotyphlum, Iheringascaris and Lapetascaris, the first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA (rDNA) of these larvae were characterised to confirm their taxonomic status. This genetic characterisation implied that some distinct morphotypes belong to different developmental stages of the same species. In addition, it revealed that some morphotypes can comprise distinct genotypes. No match was found between ITS-1 and ITS-2 sequences obtained from larvae in the present study and those from adults available in the GenBank, highlighting the lack of knowledge on occurrence of adult nematodes infecting Australian fish.
Diagnosis of canine echinococcosis: comparison of coproantigen and serum antibody tests with arecoline purgation in Uruguay
Publisher: Elsevier BV
Date: 02-1995
DOI: 10.1016/0304-4017(94)00680-B
Abstract: Echinococcus granulosus is one of the most important and widespread of the helminth zoonoses. Diagnosis of E. granulosus infection in dogs currently relies on arecoline dosing and detailed examination of the purge for adult worms. Two immunodiagnostic tests (ELISA) based on genus specific coproantigen detection or serum antibody (IgG, IgA and IgE) detection were compared against arecoline purgation for the detection of Echinococcus in naturally infected dogs in Uruguay. The coproantigen ELISA had a sensitivity of 76.9% compared with 34.6% for the serum IgG ELISA when assessed against 26 purge positive dogs (purge worm count range 1-4331). Coproantigen reactivity was positively correlated (r = 0.65) to purge worm count, with a threshold at over 20 worms. There was no positive correlation of antibody levels with worm counts. In 26 matched Echinococcus positive dog s les, the overall sensitivity of serological detection increased to 69.2% when seroreactivity for IgA and IgE antibodies were included and to 96.2% for both coproantigen and antibody assays combined. The detection of current infection of in idual dogs with E. granulosus by coproantigen ELISA has the potential to replace arecoline purgation, while specific serum antibody detection should be useful in assessing Echinococcus exposure in dog populations.
The Relevance of Structural Biology in Studying Molecules Involved in Parasite–Host Interactions: Potential for Designing New Interventions
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/CH14304
Abstract: New interventions against infectious diseases require a detailed knowledge and understanding of pathogen–host interactions and pathogeneses at the molecular level. The combination of the considerable advances in systems biology research with methods to explore the structural biology of molecules is poised to provide new insights into these areas. Importantly, exploring three-dimensional structures of proteins is central to understanding disease processes, and establishing structure–function relationships assists in identification and assessment of new drug and vaccine targets. Frequently, the molecular arsenal deployed by invading pathogens, and in particular parasites, reveals a common theme whereby families of proteins with conserved three-dimensional folds play crucial roles in infectious processes, but in idual members of such families show high levels of specialisation, which is often achieved through grafting particular structural features onto the shared overall fold. Accordingly, the applicability of predictive methodologies based on the primary structure of proteins or genome annotations is limited, particularly when thorough knowledge of molecular-level mechanisms is required. Such instances exemplify the need for experimental three-dimensional structures provided by protein crystallography, which remain an essential component of this area of research. In the present article, we review two ex les of key protein families recently investigated in our laboratories, which could represent intervention targets in the metabolome or secretome of parasites.
Seroprevalence Estimates of Latent and Acute Toxoplasma Infections in HIV+ People—Call for Action in Underprivileged Communities
Publisher: MDPI AG
Date: 26-09-2021
DOI: 10.3390/MICROORGANISMS9102034
Abstract: We undertook a comprehensive, systematic review of observational studies to estimate respective seroprevalences of latent and acute Toxoplasma gondii infections in HIV+ people at the global, regional and country levels related seroprevalence to socio-economic variables and CD4+ cell counts and assessed temporal changes in prevalence and risk factors for this group. We systematically searched international databases for seroepidemiological surveys between 1 January 1980 and 31 July 2020. We used a random effects model to calculate pooled seroprevalences with 95% confidence intervals (CI), and estimated the numbers of HIV+ people inferred to harbour latent and acute T. gondii infections (LT or AT). We grouped seroprevalence data according to the geographic regions defined by the World Health Organization (WHO) and conducted subgroup and meta-regression analyses of the data. Of a total of 4024 studies identified, 150 and 65 of them met the inclusion criteria for LT and AT in HIV+ people, respectively. The overall, pooled seroprevalences of LT and AT were 37.4% (95% CI, 33.4–41.4) and 1.3% (95% CI, 0.9–1.8%), equating to ~14.2 and 0.5 million HIV+ people, respectively. Most HIV+ people with T. gondii infections originated from Africa, and the highest seroprevalences were in low-income countries with low human development indices. Significant risk factors for toxoplasmosis in HIV+ patients included the consumption of raw/undercooked meat, frequent contact with soil, a low CD4+ T lymphocyte number ( cells per μL) and age. Overall, the finding of high seroprevalences of particularly latent T. gondii infection in HIV+ people in underprivileged regions of the world, such as parts of Africa, calls for preventative action. Programs that include routine serological monitoring, counselling, care, animal control and/or prophylactic treatment measures are needed to prevent severe toxoplasmosis from developing in people living with HIV infection. Our study highlights the potential importance of parasite chemoprophylaxis in resource-poor settings, particularly in low-income countries.
Analysis of the transcriptome of adult Dictyocaulus filaria and comparison with Dictyocaulus viviparus, with a focus on molecules involved in host-parasite interactions
Publisher: Elsevier BV
Date: 03-2014
An integrated pipeline for next-generation sequencing and annotation of mitochondrial genomes
Publisher: Oxford University Press (OUP)
Date: 05-11-2009
DOI: 10.1093/NAR/GKP883
Evolution of sexual systems, sex chromosomes and sex-linked gene transcription in flatworms and roundworms
Publisher: Springer Science and Business Media LLC
Date: 10-06-2022
DOI: 10.1038/S41467-022-30578-Z
Abstract: Many species with separate male and female in iduals (termed ‘gonochorism’ in animals) have sex-linked genome regions. Here, we investigate evolutionary changes when genome regions become completely sex-linked, by analyses of multiple species of flatworms (Platyhelminthes among which schistosomes recently evolved gonochorism from ancestral hermaphroditism), and roundworms (Nematoda) which have undergone independent translocations of different autosomes. Although neither the evolution of gonochorism nor translocations fusing ancestrally autosomal regions to sex chromosomes causes inevitable loss of recombination, we document that formerly recombining regions show genomic signatures of recombination suppression in both taxa, and become strongly genetically degenerated, with a loss of most genes. Comparisons with hermaphroditic flatworm transcriptomes show masculinisation and some defeminisation in schistosome gonad gene expression. We also find evidence that evolution of sex-linkage in nematodes is accompanied by transcriptional changes and dosage compensation. Our analyses also identify sex-linked genes that could assist future research aimed at controlling some of these important parasites.
Polymerase chain reaction‐linked single‐strand conformation polymorphism of ribosomal DNA to fingerprint parasites
Publisher: Wiley
Date: 1997
Abstract: To overcome limitations of the morphological identification of some parasites (and their different developmental stages) to species, we have established a polymerase chain reaction-linked single-strand conformation polymorphism technique (PCR-SSCP) utilizing the second internal transcribed spacer (ITS-2) of ribosomal (r)DNA. This spacer was specifically chosen in the study of strongylid and ascarid nematodes because it is known to provide reliable species markers. The ITS-2 from in idual parasites was lified by PCR, then denatured and subjected to electrophoresis on a mutation detection enhancement (MDE) (nondenaturing) gel matrix. PCR-SSCP analysis showed that the single-strand ITS-2 patterns produced allowed the accurate identification of species. The method also allowed the display of (low-level) variation in patterns within some species between different geographical isolates. These findings demonstrate the usefulness of PCR-SSCP of ITS-2 for the identification of nematode species and indicate its potential for resolving variation in the ITS-2 sequence within species.
Classification of Cryptosporidium species from patients with sporadic cryptosporidiosis by use of sequence-based multilocus analysis following mutation scanning
Publisher: American Society for Microbiology
Date: 07-2008
DOI: 10.1128/JCM.00116-08
Abstract: In the present study, we analyzed genetic variation in Cryptosporidium species from humans ( n = 62) with clinical cryptosporidiosis in South Australia. Sequence variation was assessed in regions within the small subunit of nuclear rRNA (p-SSU), the 70-kDa heat shock protein (p- hsp70 ), and the 60-kDa glycoprotein (p- gp60 ) genes by employing single-strand conformation polymorphism analysis and sequencing. Based on the analyses of p-SSU and p- hsp70 , Cryptosporidium hominis ( n = 38) and Cryptosporidium parvum ( n = 24) were identified. The analysis of p- gp60 revealed eight distinct subgenotypes, classified as C. hominis IaA17R1 ( n = 3), IbA9G3R2 ( n = 14), IbA10G2R2 ( n = 20), and IfA12G1R1 ( n = 1), as well as C. parvum IIaA18G3R1 ( n = 15), IIaA20G3R1 ( n = 6), IIaA22G4R1 ( n = 2), and IIcA5G3R2 ( n = 1). Subgenotypes IaA17R1 and IIaA22G4R1 are new. Of the six other subgenotypes, IbA10G2R2, IIaA18G3R1, IIaA20G3R1, and IIcA5G3R2 were reported previously from the state of Victoria. This is the fourth record in Australia of C. parvum subgenotype IIaA18G3R1 from humans, which, to date, has been isolated only from cattle in other countries. This subgenotype might be a significant contributor to sporadic human cryptosporidiosis and may indicate a greater zoonotic contribution to the infection of humans in the area of study. Comparative analyses revealed, for the first time, the differences in the genetic makeup of Cryptosporidium populations between two relatively close, major metropolitan cities.
How qPCR complements the WHO roadmap (2021–2030) for soil-transmitted helminths
Publisher: Elsevier BV
Date: 08-2021
Abstract: Complementing the launch of the World Health Organization (WHO) roadmap (2021-2030) we explore key elements needing attention before recruitment of qPCR as the main diagnostics tool to confirm reduction or elimination of soil-transmitted helminth (STH) transmission in both control and elimination programmes. Given the performance limitations of conventional methods, a proposed harmonised qPCR will provide a diagnostic tool, with the sensitivity and specificity required to monitor low-intensity infections, following mass drug administration (MDA). Technical and logistical challenges associated with introducing qPCR as a stand-alone tool are highlighted, and a decision-making scheme on how qPCR can support surveillance, resistance detection, and elimination is presented. An accurate point-of-care (POC) diagnostic test needs to be developed to support STH control in the field, and STH biorepositories need to be established and maintained to ensure that reference materials are available for research and validation.
Mitochondrial and Nuclear Ribosomal DNA Evidence Supports the Existence of a New Trichuris Species in the Endangered François’ Leaf-Monkey
Publisher: Public Library of Science (PLoS)
Date: 20-06-2013
Phenotypic screening of the ‘Kurz-box’ of chemicals identifies two compounds (BLK127 and HBK4) with anthelmintic activity in vitro against parasitic larval stages of Haemonchus contortus
Publisher: Springer Science and Business Media LLC
Date: 30-04-2019
The genome and developmental transcriptome of the strongylid nematode Haemonchus contortus
Publisher: Springer Science and Business Media LLC
Date: 2013
Differentiation of Haemonchus placei from H. contortus (Nematoda: Trichostrongylidae) by the ribosomal DNA second internal transcribed spacer
Publisher: Elsevier BV
Date: 04-1995
DOI: 10.1016/0020-7519(94)00156-I
Abstract: There has been much debate as to whether H. placei is a separate species to H. contortus. The aim of this study is to provide molecular information to assess the species status of H. placei. Using the polymerase chain reaction, the second internal transcribed spacer (ITS-2) of ribosomal DNA was lified and sequenced. Comparison of the 231 base pair ITS-2 sequences showed no intraspecific variation in H. contortus, among one isolate from each of the United Kingdom. Switzerland and China and 5 isolates from within Australia, or among 3 Australian isolates of H. placei. Three (1.3%) nucleotide differences were detected between the ITS-2 sequences of H. contortus and H. placei. In addition, 2 diagnostic sites for the endonucleases BfaI and FokI allowed the delineation of H. placei from H. contortus. The data presented herein support previous morphological and genetic evidence that H. placei is a separate species to H. contortus.
Use of a molecular approach for the definitive diagnosis of proliferative larval mesocestoidiasis in a cat
Publisher: Elsevier BV
Date: 10-2012
DOI: 10.1016/J.MEEGID.2012.04.014
Abstract: A 9 year-old male, neutered cat with a history of a sudden onset of lethargy, anorexia and respiratory distress was presented in a veterinary practice in Lucca, Italy. A clinical examination revealed that the cat was severely dehydrated, and had pale mucous membranes and tachypnoea. No pain or discomfort was detected at the time of physical examination. The cat was administered fluids, antibiotics and supportive therapy, but died overnight. The owner of the cat requested for a post mortem examination to be conducted. At necropsy, acephalic structures, consistent with proliferative tapeworm (cestode) larvae, were detected in the thoracic cavity on pleural surfaces. As these larvae could not be identified to genus or species by microscopy, a PCR-based sequencing-phylogenetic approach was used. Part of the cytochrome c oxidase subunit 1 gene was PCR- lified from genomic DNAs from five in idual larvae and sequenced all five sequences obtained were identical. This consensus sequence was aligned (over 355 nucleotide positions) with homologous sequences representing a range of cestodes (including Echinococcus granulosus, Echinococcus multilocularis, Hymenolepis microstoma, Mesocestoides spp. and Taenia saginata) from previously published studies and then subjected to phylogenetic analysis. The sequence representing the larval cestode from the affected cat grouped, with strong statistical support, with those representing Mesocestoides corti and Mesocestoides lineatus. Therefore, a definitive diagnosis of pleural proliferative larval mesocestoidiasis could be made. This study illustrates the value of using molecular tools to directly assist clinical and pathological investigations of cestodiases of animals.
Proteomic identification of galectin- 11 and 14 ligands from Haemonchus contortus
Publisher: PeerJ
Date: 19-03-2018
DOI: 10.7717/PEERJ.4510
Abstract: Haemonchus contortus is the most pathogenic nematode of small ruminants. Infection in sheep and goats results in anaemia that decreases animal productivity and can ultimately cause death. The involvement of ruminant-specific galectin-11 (LGALS-11) and galectin-14 (LGALS-14) has been postulated to play important roles in protective immune responses against parasitic infection however, their ligands are unknown. In the current study, LGALS-11 and LGALS-14 ligands in H. contortus were identified from larval (L4) and adult parasitic stages extracts using immobilised LGALS-11 and LGALS-14 affinity column chromatography and mass spectrometry. Both LGALS-11 and LGALS-14 bound more putative protein targets in the adult stage of H. contortus (43 proteins) when compared to the larval stage (two proteins). Of the 43 proteins identified in the adult stage, 34 and 35 proteins were bound by LGALS-11 and LGALS-14, respectively, with 26 proteins binding to both galectins. Interestingly, hematophagous stage-specific sperm-coating protein and zinc metalloprotease (M13), which are known vaccine candidates, were identified as putative ligands of both LGALS-11 and LGALS-14. The identification of glycoproteins of H. contortus by LGALS-11 and LGALS-14 provide new insights into host-parasite interactions and the potential for developing new interventions.
A mutation scanning approach for the identification of hookworm species and analysis of population variation
Publisher: Elsevier BV
Date: 05-1998
DOI: 10.1016/S0166-6851(98)00008-5
Abstract: To overcome limitations in the morphological identification of different developmental stages of hookworms to species, we have established a polymerase chain reaction-linked single strand conformation polymorphism technique (PCR-SSCP) utilizing the internal transcribed spacers (ITS) of ribosomal (r)DNA. These spacers were specifically chosen because they provide reliable species markers for strongylid nematodes. ITS spacers were lified by PCR from DNA derived from in idual parasites of seven species of hookworm, then denatured and subjected to electrophoresis in a mutation detection enhancement (MDE) (non-denaturing) gel matrix. PCR SSCP analysis showed that the single-strand ITS patterns produced allowed the unequivocal identification of all species. The method also allowed the direct display of sequence variation within some species where multiple in idual worms were examined. These findings demonstrate the usefulness of the SSCP approach for hookworm identification, the detection of population variation and the direct display of sequence variation in rDNA.
Getting to the guts of the matter: the status and potential of 'omics' research of parasitic protists of the human gastrointestinal system.
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.IJPARA.2013.06.005
Abstract: Parasitic protists are a major cause of diarrhoeal illnesses in humans globally. Collectively, enteric pathogens exceed all other forms of infectious disease, in terms of their estimated global prevalence and socioeconomic impact. They have a disproportionately high impact on children in impoverished communities, leading to acute (diarrhoea, vomiting, dehydration and death) and chronic disease (malabsorption, malnutrition, physical and cognitive stunting and predisposition to chronic, non-communicable disease) consequences. However, historically, investment in research and disease control measures has been disproportionately poor, leading to their current classification as neglected pathogens. A sound understanding of their biology is essential in underpinning detection, treatment and control efforts. One major tool in rapidly improving our knowledge of these parasites is the use of biological systems, including 'omic' technologies. In recent years, these tools have shown significant success when applied to enteric protists. This review summarises much of this knowledge and highlights the significant remaining knowledge gaps. A major focus of the present review was to provide a perspective on a way forward to address these gaps using advanced biotechnologies.
Advances in kinome research of parasitic worms - implications for fundamental research and applied biotechnological outcomes
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.BIOTECHADV.2018.02.013
Abstract: Protein kinases are enzymes that play essential roles in the regulation of many cellular processes. Despite expansions in the fields of genomics, transcriptomics and bioinformatics, there is limited information on the kinase complements (kinomes) of most eukaryotic organisms, including parasitic worms that cause serious diseases of humans and animals. The biological uniqueness of these worms and the draft status of their genomes pose challenges for the identification and classification of protein kinases using established tools. In this article, we provide an account of kinase biology, the roles of kinases in diseases and their importance as drug targets, and drug discovery efforts in key socioeconomically important parasitic worms. In this context, we summarise methods and resources commonly used for the curation, identification, classification and functional annotation of protein kinase sequences from draft genomes review recent advances made in the characterisation of the worm kinomes and discuss the implications of these advances for investigating kinase signalling and developing small-molecule inhibitors as new anti-parasitic drugs.
Fingerprinting sequence variation in ribosomal DNA of parasites by DGGE
Publisher: Elsevier BV
Date: 04-1996
Abstract: Although there is a tendency for rDNA genes within a species to maintain sequence homogeneity, there can be significant levels of variation among rDNA repeat sequences within populations or in iduals of a species as a consequence of mutation mechanisms. To date, there have been no practical techniques available in molecular parasitology that allow the extent of sequence variation among the repeats (i.e., number of sequence types) to be displayed visually. In this report, we describe the use of the denaturing gradient gel electrophoresis (DGGE) technique for the rapid screening of parasite rDNA for sequence variation without the need for exhaustive cloning or DNA sequencing. The resolution of this variation by DGGE provides a diagnostic fingerprint for a species.
TripletCell: a deep metric learning framework for accurate annotation of cell types at the single-cell level
Publisher: Oxford University Press (OUP)
Date: 20-04-2023
DOI: 10.1093/BIB/BBAD132
Abstract: Single-cell RNA sequencing (scRNA-seq) has significantly accelerated the experimental characterization of distinct cell lineages and types in complex tissues and organisms. Cell-type annotation is of great importance in most of the scRNA-seq analysis pipelines. However, manual cell-type annotation heavily relies on the quality of scRNA-seq data and marker genes, and therefore can be laborious and time-consuming. Furthermore, the heterogeneity of scRNA-seq datasets poses another challenge for accurate cell-type annotation, such as the batch effect induced by different scRNA-seq protocols and s les. To overcome these limitations, here we propose a novel pipeline, termed TripletCell, for cross-species, cross-protocol and cross-s le cell-type annotation. We developed a cell embedding and dimension-reduction module for the feature extraction (FE) in TripletCell, namely TripletCell-FE, to leverage the deep metric learning-based algorithm for the relationships between the reference gene expression matrix and the query cells. Our experimental studies on 21 datasets (covering nine scRNA-seq protocols, two species and three tissues) demonstrate that TripletCell outperformed state-of-the-art approaches for cell-type annotation. More importantly, regardless of protocols or species, TripletCell can deliver outstanding and robust performance in annotating different types of cells. TripletCell is freely available at iuyan3056/TripletCell. We believe that TripletCell is a reliable computational tool for accurately annotating various cell types using scRNA-seq data and will be instrumental in assisting the generation of novel biological hypotheses in cell biology.
Cryptosporidium and Giardia taxa in faecal samples from animals in catchments supplying the city of Melbourne with drinking water (2011 to 2015)
Publisher: Springer Science and Business Media LLC
Date: 06-2016
Is Cryptosporidium from the common wombat (Vombatus ursinus) a new species and distinct from Cryptosporidium ubiquitum?
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.MEEGID.2016.06.028
Abstract: The emerging zoonotic pathogen Cryptosporidium ubiquitum has been found in a variety of mammalian hosts, including humans, throughout the world. Advances in the molecular characterization of this parasite using the sequence of the 60kDa glycoprotein (gp60) gene have allowed the classification of "subtypes". Sequences derived from faecal s les from the common wombat (Vombatus ursinus) have identified a novel gp60 subtype designated here as C. ubiquitum XIIg. Phylogenetic analysis suggests that subtypes of C. ubiquitum can be ided into generalist and specialist groups, which is important when considering the zoonotic potential of C. ubiquitum in the context of drinking water safety.
Detection of cryptic species of Rugopharynx (Nematoda: Strongylida) from the stomachs of Australian macropodid marsupials.
Publisher: Elsevier BV
Date: 08-2016
Combined use of feature engineering and machine-learning to predict essential genes in Drosophila melanogaster
Publisher: Oxford University Press (OUP)
Date: 22-07-2020
Abstract: Characterizing genes that are critical for the survival of an organism (i.e. essential) is important to gain a deep understanding of the fundamental cellular and molecular mechanisms that sustain life. Functional genomic investigations of the vinegar fly, Drosophila melanogaster, have unravelled the functions of numerous genes of this model species, but results from phenomic experiments can sometimes be ambiguous. Moreover, the features underlying gene essentiality are poorly understood, posing challenges for computational prediction. Here, we harnessed comprehensive genomic-phenomic datasets publicly available for D. melanogaster and a machine-learning-based workflow to predict essential genes of this fly. We discovered strong predictors of such genes, paving the way for computational predictions of essentiality in less-studied arthropod pests and vectors of infectious diseases.
Long pcr amplification of the entire mitochondrial genome from individual helminths for direct sequencing
Publisher: Springer Science and Business Media LLC
Date: 20-09-2007
Abstract: Exploring mitochondrial (mt) genomes has significant implications for various fundamental research areas, including mt biochemistry and physiology, and, importantly, such genomes provide a rich source of markers for population genetics and systematic studies. Although some progress has been made, there is a paucity of information on mt genomes for many metazoan organisms, particularly invertebrates such as parasitic helminths, which relates mainly to the technical limitations associated with sequencing from tiny amounts of material. In this article, we describe a practical long PCR approach for the lification and subsequent sequencing of the entire mt genome from in idual helminths, which overcomes these limitations. The protocol includes the isolation of genomic DNA, long PCR lification, electrophoresis and sequencing, and takes approximately 1-3 weeks to carry out. The present user-friendly, cost-effective approach has demonstrated utility to the study of a range of parasites, and has the potential to be applied to a wide range of organisms.
Rapid, multiplex-tandem PCR assay for automated detection and differentiation of toxigenic cyanobacterial blooms
Publisher: Elsevier BV
Date: 10-2013
DOI: 10.1016/J.MCP.2013.07.001
Abstract: Cyanobacterial blooms are a major water quality issue and potential public health risk in freshwater, marine and estuarine ecosystems globally, because of their potential to produce cyanotoxins. To date, a significant challenge in the effective management of cyanobacterial has been an inability of classical microscopy-based approaches to consistently and reliably detect and differentiate toxic from non-toxic blooms. The potential of cyanobacteria to produce toxins has been linked to the presence of specific biosynthetic gene clusters. Here, we describe the application of a robotic PCR-based assay for the semi-automated and simultaneous detection of toxin biosynthesis genes of each of the toxin classes characterized to date for cyanobacteria [i.e., microcystins (MCYs), nodularins (NODs), cylindrospermopsins (CYNs) and paralytic shellfish toxins (PSTs)/saxitoxins (SXTs)]. We demonstrated high sensitivity and specificity for each assay using well-characterized, cultured isolates, and establish its utility as a quantitative PCR using DNA, clone and cell-based dilution series. In addition, we used 206 field-collected s les and 100 known negative controls to compare the performance of each assay with conventional PCR and direct toxin detection. We report a diagnostic specificity of 100% and a sensitivity of ≥97.7% for each assay.
The small RNA complement of adult Schistosoma haematobium
Publisher: Public Library of Science (PLoS)
Date: 29-05-2018
Probing the equatorial groove of the hookworm protein and vaccine candidate antigen, Na-ASP-2
Publisher: Elsevier BV
Date: 05-2014
DOI: 10.1016/J.BIOCEL.2014.03.003
Abstract: Hookworm activation-associated secreted proteins can be structurally classified into at least three different groups. The hallmark feature of Group 1 activation-associated secreted proteins is a prominent equatorial groove, which is inferred to form a ligand binding site. Furthermore, a conserved tandem histidine motif is located in the centre of the groove and believed to provide or support a yet to be determined catalytic activity. Here, we report three-dimensional crystal structures of Na-ASP-2, an L3-secreted activation-associated secreted protein from the human hookworm Necator americanus, which demonstrate transition metal binding ability of the conserved tandem histidine motif. We further identified moderate phosphohydrolase activity of recombinant Na-ASP-2, which relates to the tandem histidine motif. By panning a random 12-mer peptide phage library, we identified a peptide with high similarity to the human calcium-activated potassium channel SK3, and confirm binding of the synthetic peptide to recombinant Na-ASP-2 by differential scanning fluorimetry. Potential binding modes of the peptide to Na-ASP-2 were studied by molecular dynamics simulations which clearly identify a preferred topology of the Na-ASP-2:SK3 peptide complex.
Meeting Report: Application of Genotyping Methods to Assess Risks from Cryptosporidium in Watersheds
Publisher: Environmental Health Perspectives
Date: 03-2006
DOI: 10.1289/EHP.8240
Abstract: A workshop titled "Application of Genotyping Methods to Assess Pathogen Risks from Cryptosporidium in Drinking Water Catchments" was held at the International Water Association biennial conference, Marrakech, Morocco, 23 September 2004. The workshop presented and discussed the findings of an interlaboratory trial that compared methods for genotyping Cryptosporidium oocysts isolated from feces. The primary goal of the trial and workshop was to assess the utility of current Cryptosporidium genotyping methods for determining the public health significance of oocysts isolated from feces in potable-water-supply watersheds. An expert panel of 16 watershed managers, public health practitioners, and molecular parasitologists was assembled for the workshop. A subordinate goal of the workshop was to educate watershed management and public health practitioners. An open invitation was extended to all conference delegates to attend the workshop, which drew approximately 50 interested delegates. In this report we summarize the peer consensus emerging from the workshop. Recommendations on the use of current methods by watershed managers and public health practitioners were proposed. Importantly, all the methods that were reported in the trial were mutually supporting and found to be valuable and worthy of further utility and development. Where there were choices as to which method to apply, the small-subunit ribosomal RNA gene was considered to be the optimum genetic locus to target. The single-strand conformational polymorphism method was considered potentially the most valuable for discriminating to the subtype level and where a large number of s les were to be analyzed. A research agenda for protozoan geneticists was proposed to improve the utility of methods into the future. Standardization of methods and nomenclature was promoted.
Isolation, propagation and characterisation of Cryptosporidium
Publisher: Elsevier BV
Date: 09-1999
DOI: 10.1016/S0020-7519(99)00113-7
Abstract: This review consists of 11 papers presented at the Consensus Conference on Cryptosporidium in Water (Parasitology Stream), held in Melbourne, Australia, from 5 to 6th October 1998. The conference was sponsored by the Water Services Association of Australia, the Australian Water and Wastewater Association, and the Collaborative Research Centre for Water Quality and Treatment. The papers summarise the advantages and disadvantages of various contemporary technologies applicable to parasite propagation and biochemical/molecular characterisation. Studies have detected distinct genetic differences between clinical isolates from humans and animals, and it is hoped that comprehensive documentation studies will facilitate the identification of environmental isolates in the not too distant future.
“Begging the Question”—Does Toxocara Infection/Exposure Associate with Multiple Sclerosis-Risk?
Publisher: MDPI AG
Date: 11-11-2020
Abstract: Although the cause of multiple sclerosis (MS) is unclear, infectious agents, including some parasitic roundworms (nematodes), have been proposed as possible risk factors or contributors. Here, we conducted a systematic review and meta-analysis of published observational studies to evaluate whether there is a possible association between infection with, or exposure to, one or more members of the genus Toxocara (phylum Nematoda superfamily Ascaridoidea) and MS. We undertook a search of public literature databases to identify relevant studies and then used a random-effects meta-analysis model to generate the pooled odds ratio (OR) and 95% confidence intervals (CIs). This search identified six of a total of 1371 articles that were relevant to the topic these published studies involved totals of 473 MS patients and 647 control subjects. Anti-Toxocara IgG serum antibodies were detected in 62 MS patients and 37 controls, resulting in respective seroprevalences of 13.1% (95% CI: 8.2–20.3) and 4.8% (95% CI: 2.5–9.2), indicating an association (pooled OR, 3.01 95% CI: 1.46–6.21). Because of the publication bias identified (six eligible studies), well-designed and -controlled studies are required in the future to rigorously test the hypothesis that Toxocara infection/exposure has an association with MS.
Mitochondrial DNA polymorphism within and among species of Capillaria sensu lato from Australian marsupials and rodents.
Publisher: Elsevier BV
Date: 07-2000
DOI: 10.1016/S0020-7519(00)00076-X
Abstract: The nucleotide variation in a mitochondrial DNA (mtDNA) fragment within and among species of Capillaria sensu lato from Australian marsupials and rodents was analyzed using a mutation scanning/sequencing approach. The fragment of the cytochrome c oxidase subunit I (COI) was lified by PCR from parasite DNA, and analysed by single-strand conformation polymorphism (SSCP) and sequencing. There was no significant variation in SSCP profiles within a morphospecies from a particular host species, but significant variation existed among morphospecies originating from different host species. The same morphospecies was found to occur in 1-3 tissue habitats within one host in idual or within different in iduals of a particular species of host from the same or different geographical areas, and morphospecies appeared to be relatively host specific at the generic level. The results indicated that the species of Capillaria sensu lato examined, although highly variable in their host and tissue specificity, may exhibit the greatest degree of specificity at the level of host genus.
The 5.8S rDNA sequences of 18 species of bursate nematodes (order Strongylida): Comparison with rhabditid and tylenchid nematodes
Publisher: Elsevier BV
Date: 1997
DOI: 10.1016/S0020-7519(96)00158-0
Abstract: The 5.8S rDNA sequences of 18 species of bursate nematode were 153 bp in length and had a G + C content of 47-50%. Interspecific differences in rDNA sequence among the bursate nematodes were low (0-5.2%), but the extent of the sequence differences between the parasitic bursate nematodes, a free-living rhabditid nematode and 2 species of parasitic tylenchid nematodes (12-33%) suggests that the 5.8S rRNA gene may provide useful phylogenetic information with respect to the relationships of the different orders within the phylum Nematoda.
Long PCR-based amplification of the entire mitochondrial genome from single parasitic nematodes
Publisher: Elsevier BV
Date: 08-2002
Abstract: Mitochondrial genome sequences provide useful markers for investigating population genetic structures because of their maternal inheritance and high evolutionary rates. There is, however, a paucity of information on mitochondrial genomes for many parasitic organisms, including nematodes, which appears to relate mainly to technical limitations and (for modestly funded laboratories) the cost associated with full mitochondrial genome sequencing. In this article, we describe a simple, relatively inexpensive long-PCR approach for the lification (using two sets of primers) of the entire mitochondrial genome from in idual parasitic nematodes for subsequent sequencing, which overcomes these limitations. We employed two species of human hookworm (Ancylostoma duodenale and Necator americanus order Strongylida) to establish the long-PCR conditions, and then extended its use to a number of other species of parasitic nematode of the class Secernentea (orders Strongylida, Ascaridida and Rhabditida). The long-PCR method for the lification of the entire mitochondrial genome from single nematodes, coupled with direct sequencing of licons, provides a useful tool for the comparative analysis of genome organisation and evolution of a range of nematode groups. It also creates a platform for molecular ecological and population genetic studies.
Analysis of genetic variation in Globocephaloides populations from macropodid marsupials using a mutation scanning-based approach
Publisher: Wiley
Date: 08-2009
Abstract: Three species of Globocephaloides, parasitic nematodes occurring in macropodid marsupials in different areas of Australia, were characterized by the sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA. S les were subjected to PCR-coupled SSCP analysis and targeted sequencing, in order to assess genetic variation within and among in iduals from different host species. Both SSCP and sequence data supported the current classification of morphospecies. Contrary to a previous hypothesis that cryptic species exist within the Globocephaloides trifidospicularis "complex", no or minor (0.2%) variation was detected among in iduals from different hosts or geographical origins. Within G. macropodis populations, there was a consistent difference in both the ITS-1 (5.2%) and ITS-2 (7.1%) sequences between in iduals derived from Macropus agilis and those from Macropus dorsalis. Although the results suggested that G. macropodis from each host species represented sibling species, future morphological study of in iduals representing each G. macropodis genotype is warranted to provide further support for this hypothesis. (Nucleotide sequence data have been deposited in the GenBank database under accession nos. GQ131400-GQ131409.).
Molecular characterization of species of Cloacina (Strongyloidea: Cloacininae) from the common wallaroo, Macropus robustus (Marsupialia: Macropodidae) in Australia.
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.MEEGID.2016.06.037
Abstract: This study examined genetic variation within and among species of Cloacina found in the common wallaroo (Macropus robustus) collected at different localities from mainland Australia, and evaluated geographical distance as a potential driver for genetic variation. The first and second internal transcribed spacers (ITS-1 and ITS-2=ITS) of nuclear ribosomal DNA were used to characterize in iduals of 17 morphospecies of Cloacina that parasitize Macropus robustus and its sub-species. Results revealed intraspecific variation in ITS within some morphospecies of Cloacina. Phylogenetic analyses showed little correlation between host speciation patterns and geographical location for the majority of the nematode species, although it did suggest geographical distance was a driver for speciation within Cloacina communis, C. phaethon and C. parva. Our results suggest that nucleotide variation within Cloacina species is complex, and is likely to be propagated by factors such as geographical distance and host sub-species. Further studies determining factors involved in speciation, such as host-parasite relationships, are needed to improve our understanding of the ersity of populations of species of Cloacina.
Antibody responses of patients with cystic hydatid disease to recombinant myophilin of Echinococcus granulosus
Publisher: Elsevier BV
Date: 08-1996
DOI: 10.1016/0001-706X(96)00012-5
Abstract: Hydatid patients were investigated for the presence of specific serum antibodies against a recombinant Echinococcus granulosus antigen, designated myophilin. The clinical history of each patient was examined to determine any correlation between factors such as cyst location and medical treatment on the presence or absence of antibodies to myophilin. Specific antibodies against recombinant myophilin were detected by Western blot analysis in 38.8% (7 of 18) of the hydatid patients examined. These patients also had the highest titres in ELISA against sheep hydatid cyst fluid antigen. There was an association between the presence of antibodies to myophilin and the patients having undergone recent treatment by chemotherapy and/or surgery, suggesting that the destruction of hydatid cysts may lead to an immune response against myophilin.
Flatworms have lost the right open reading frame kinase 3 gene during evolution
Publisher: Springer Science and Business Media LLC
Date: 15-05-2015
DOI: 10.1038/SREP09417
Abstract: All multicellular organisms studied to date have three ri ght o pen reading frame kinase genes (designated riok-1 , riok-2 and riok-3 ). Current evidence indicates that riok-1 and riok-2 have essential roles in ribosome biosynthesis and that the riok-3 gene assists this process. In the present study, we conducted a detailed bioinformatic analysis of the riok gene family in 25 parasitic flatworms (platyhelminths) for which extensive genomic and transcriptomic data sets are available. We found that none of the flatworms studied have a riok-3 gene, which is unprecedented for multicellular organisms. We propose that, unlike in other eukaryotes, the loss of RIOK-3 from flatworms does not result in an evolutionary disadvantage due to the unique biology and physiology of this phylum. We show that the loss of RIOK-3 coincides with a loss of particular proteins associated with essential cellular pathways linked to cell growth and apoptosis. These findings indicate multiple, key regulatory functions of RIOK-3 in other metazoan species. Taking advantage of a known partial crystal structure of human RIOK-1, molecular modelling revealed variability in nucleotide binding sites between flatworm and human RIOK proteins.
Functional genomic exploration reveals that Ss-RIOK-1 is essential for the development and survival of Strongyloides stercoralis larvae
Publisher: Elsevier BV
Date: 12-2017
Molecular characterization of Theileria orientalis from cattle in Ethiopia
Publisher: Elsevier BV
Date: 07-2016
DOI: 10.1016/J.TTBDIS.2016.03.005
Abstract: This study reports the first molecular characterization of Theileria orientalis in local breeds of cattle in Ethiopia. A conventional PCR utilizing major piroplasm surface protein (MPSP) gene and an established multiplexed tandem PCR (MT-PCR) were used to characterize T. orientalis and to assess the infection intensity, respectively. Of 232 blood s les tested, T. orientalis DNA was detected in only 2.2% of s les using conventional PCR two genotypes buffeli (1.3% 3/232) and type 5 (0.9% 2/232) of T. orientalis were detected. Phylogenetic analysis revealed that the buffeli MPSP sequences from Ethiopia were closely related to those reported from Kenya, Sri Lanka and Myanmar, and type 5 sequences from Ethiopia grouped with those from Korea, Japan, Vietnam and Thailand. A higher number of s les (3.9% 9/232) were test-positive by MT-PCR and four genotypes (buffeli, chitose, ikeda and type 5) of T. orientalis were detected. The average intensity of infections with genotypes buffeli (DNA copy numbers 11,056) and type 5 (7508) were significantly higher (P<0.0001) than the pathogenic genotype ikeda (61 DNA copies). This first insight into T. orientalis from cattle in Ethiopia using MPSP gene provides a basis for future studies of T. orientalis in various agroclimatic zones and of the impact of oriental theilerosis on cattle in this and other countries of Africa.
Rapid PCR-based delineation of the porcine nodular worms,Oesophagostomum dentatumandO. quadrispinulatum
Publisher: Elsevier BV
Date: 04-1997
Abstract: At some stages of development, it is impossible to identify the porcine nodular worms Oesophagostomum dentatum and O. quadrispinulatum to the species level using morphological parameters. A molecular approach utilizing genetic markers in the second internal transcribed spacer (ITS-2) of ribosomal (r) DNA was developed to overcome this limitation. The ITS-2 sequence of each species was determined, and specific oligonucleotide primers were designed to regions of greatest sequence difference between the species. Utilizing these primers, rapid PCR procedures were developed for the specific lification of DNA of O. dentatum or O. quadrispinulatum, which are now used routinely to monitor the purity of larval cultures and to confirm the identity of larvae derived from the intestine or faeces. The application of specific PCR has major implications for studying the population biology of nodular worms in the pig model.
Real-time polymerase chain reaction (PCR) assays for the specific detection and quantification of seven Eimeria species that cause coccidiosis in chickens
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.1016/J.MCP.2008.12.005
Abstract: Coccidiosis of chickens is an economically important disease caused by infection with species of Eimeria. The oocysts of some of the seven recognized species are difficult to distinguish morphologically and for this reason diagnostic laboratories are increasingly utilizing DNA-based technologies for the specific identification of Eimeria. The real-time PCR provides both sensitivity and speed for the analysis of DNA s les, and the approach has the capability of quantifying DNA. Together with a protocol for the extraction of DNA directly from faecal s les, real-time PCR assays have been established for the detection and quantification of seven species of Eimeria that infect chickens in Australia. The assays target one genetic marker, the second internal transcribed spacer of nuclear ribosomal DNA (ITS-2), use TaqMan MGB technology with species-specific probes, and can be multiplexed in pairs such that the seven species of Eimeria can be screened in four reaction tubes. A test screen of commercial flocks identified more Eimeria-infected chickens than were detected by coproscopic examination for oocysts. These molecular assays can also be used for the quality control of mixed-species vaccines. The ability to multiplex the assays makes them particularly practical for screening s les from chickens with mixed-species infections where the relative abundance of each Eimeria species present is required.
Clonorchis sinensis and Clonorchiasis: The Relevance of Exploring Genetic Variation
Publisher: Elsevier
Date: 2018
DOI: 10.1016/BS.APAR.2018.03.006
Abstract: Parasitic trematodes (flukes) cause substantial mortality and morbidity in humans. The Chinese liver fluke, Clonorchis sinensis, is one of the most destructive parasitic worms in humans in China, Vietnam, Korea and the Russian Far East. Although C. sinensis infection can be controlled relatively well using anthelmintics, the worm is carcinogenic, inducing cholangiocarcinoma and causing major suffering in ~15 million people in Asia. This chapter provides an account of C. sinensis and clonorchiasis research-covering aspects of biology, epidemiology, pathogenesis and immunity, diagnosis, treatment and control, genetics and genomics. It also describes progress in the area of molecular biology (genetics, genomics, transcriptomics and proteomics) and highlights challenges associated with comparative genomics and population genetics. It then reviews recent advances in the sequencing and characterisation of the mitochondrial and nuclear genomes for a Korean isolate of C. sinensis and summarises salient comparative genomic work and the implications thereof. The chapter concludes by considering how advances in genomic and informatics will enable research on the genetics of C. sinensis and related parasites, as well as the discovery of new fluke-specific intervention targets.
Initial support for the hypothesis that PAR2 is involved in the immune response to Nippostrongylus brasiliensis in mice
Publisher: Springer Science and Business Media LLC
Date: 14-02-2007
DOI: 10.1007/S00436-007-0467-1
Abstract: Protease-activated receptor 2 (PAR(2)) is a cell surface receptor that detects trypsin and trypsin-like enzymes. Although the precise pathophysiological roles of PAR(2) are yet to be determined, the receptor has been broadly implicated in inflammation and allergy. However, no studies have investigated the possible roles of PAR(2) in hosts infected by parasitic helminths. Therefore, in this preliminary investigation, we compared the infectivity of the nematode Nippostrongylus brasiliensis in mice lacking the PAR(2) gene (PAR2-/- ) and in their 'background-strain' controls (129SV). PAR2-/- mice displayed elevated fecal egg counts and decreased levels of total serum IgE, after a subcutaneous infection with 900 infective third-stage N. brasiliensis larvae compared with 129SV mice that were not susceptible to infection. In addition, in a separate study in BALB/c mice, two immunological hallmarks of parasite infection, IgE- and IL-10-expressing lymphocytes, were shown to be augmented after the coadministration of the classic antigen ovalbumin with the PAR(2)-activating peptide SLIGRL (single letter amino acid sequence) but not the inactive reverse peptide LRGILS. These findings provide initial support for the proposal that PAR(2) is a recognition receptor for nematode-derived proteases.
Mutation scanning-coupled sequencing of nuclear ribosomal DNA spacers as a tool for the specific identification of different Contracaecum (Nematoda: Anisakidae) larval types
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.MCP.2010.09.003
Abstract: In the present study, various morphotypes of Contracaecum (Nematoda) larvae in different developmental stages were described and then genetically characterised using sequence data obtained from the first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA (rDNA). The alignment of ITS-1 and ITS-2 sequence data for larvae investigated with those from well characterised adults in previous studies showed that fourth-stage Contracaecum larvae from the Australian pelican, Pelecanus conspicillatus, had the same sequence as Contracaecum microcephalum reported from the little pied cormorant, Phalacrocorax melanoleucos. In addition, four different morphotypes of third-stage larvae, including types I to IV, were found in various species of fish. Contracaecum type I larvae were composed of two distict genotypes those collected from mullet, Mugil cephalus, had the same sequence as C. multipapillatum, and those from an unknown species of hardyhead (family Atherinidae) were C. pyripapillatum. Contracaecum type II larvae from mackerel, Scomber australasicus, had the same sequence as adult C. ogmorhini sensu stricto, found in the Australian and New Zealand fur seals (Arctocephalus spp). Contracaecum type III larvae from flathead, Platycephalus laevigatus, had the same sequence as C. rudolphii D found in the black cormorant, Phalacrocorax carbo. The approach used herein was an effective means of matching incompletely identifiable larval nematodes with reference sequences and provides a basis for exploring the composition of populations of anisakid larvae in fish as well as their ecology, particularly their life cycles and transmission patterns.
Mitochondrial genome of Hypoderaeum conoideum - Comparison with selected trematodes
Publisher: Springer Science and Business Media LLC
Date: 12-02-2015
Improved genomic resources and new bioinformatic workflow for the carcinogenic parasite Clonorchis sinensis: Biotechnological implications
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.BIOTECHADV.2018.02.008
Abstract: Clonorchis sinensis (family Opisthorchiidae) is an important foodborne parasite that has a major socioeconomic impact on ~35 million people predominantly in China, Vietnam, Korea and the Russian Far East. In humans, infection with C. sinensis causes clonorchiasis, a complex hepatobiliary disease that can induce cholangiocarcinoma (CCA), a malignant cancer of the bile ducts. Central to understanding the epidemiology of this disease is knowledge of genetic variation within and among populations of this parasite. Although most published molecular studies seem to suggest that C. sinensis represents a single species, evidence of karyotypic variation within C. sinensis and cryptic species within a related opisthorchiid fluke (Opisthorchis viverrini) emphasise the importance of studying and comparing the genes and genomes of geographically distinct isolates of C. sinensis. Recently, we sequenced, assembled and characterised a draft nuclear genome of a C. sinensis isolate from Korea and compared it with a published draft genome of a Chinese isolate of this species using a bioinformatic workflow established for comparing draft genome assemblies and their gene annotations. We identified that 50.6% and 51.3% of the Korean and Chinese C. sinensis genomic scaffolds were syntenic, respectively. Within aligned syntenic blocks, the genomes had a high level of nucleotide identity (99.1%) and encoded 15 variable proteins likely to be involved in erse biological processes. Here, we review current technical challenges of using draft genome assemblies to undertake comparative genomic analyses to quantify genetic variation between isolates of the same species. Using a workflow that overcomes these challenges, we report on a high-quality draft genome for C. sinensis from Korea and comparative genomic analyses, as a basis for future investigations of the genetic structures of C. sinensis populations, and discuss the biotechnological implications of these explorations.
PCR-coupled sequencing achieves specific diagnosis of onchocerciasis in a challenging clinical case, to underpin effective treatment and clinical management.
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.MEEGID.2018.09.012
Abstract: This study demonstrates the utility of a PCR-based DNA sequencing approach to make a specific diagnosis of onchocerciasis in a returned traveller. Although a clinical diagnosis was not possible, the surgical excision of a suprascapular nodule from this patient, combined with an histological examination of this nodule and PCR-based sequencing of DNA from a nematode from this lesion solved the case. The analysis of DNA sequence data confirmed the presence of Onchocerca volvulus infection, supporting an effective treatment-clinical management strategy for the patient.
Deguelin exerts potent nematocidal activity via the mitochondrial respiratory chain
Publisher: Wiley
Date: 07-07-2017
PCR-based technology in veterinary parasitology
Publisher: Elsevier BV
Date: 08-1999
DOI: 10.1016/S0304-4017(99)00036-9
Abstract: DNA technology is having a major impact in many areas of veterinary parasitology. In particular, the polymerase chain reaction (PCR) has found broad applicability because its sensitivity permits enzymatic lification of gene fragments from minute quantities of nucleic acids derived from limited amounts of parasite material. This paper discusses some recent applications of PCR-based methods to parasites and highlights their usefulness or potential for those of veterinary importance. The focus is on PCR tools for the accurate identification of parasites and their genetic characterisation, the diagnosis of infections, the isolation and characterisation of expressed genes, the detection of anthelmintic resistance, and mutation scanning approaches for the high resolution analysis of PCR products.
Somatic proteome of Haemonchus contortus
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.IJPARA.2018.12.003
Abstract: Currently, there is a dearth of proteomic data to underpin fundamental investigations of parasites and parasitism at the molecular level. Here, using a high throughput LC-MS/MS-based approach, we undertook the first reported comprehensive, large-scale proteomic investigation of the barber's pole worm (Haemonchus contortus) - one of the most important parasitic nematodes of livestock animals worldwide. In total, 2487 unique H. contortus proteins representing different developmental stages/sexes (i.e. eggs, L3s and L4s, female (Af) and male (Am) adults) were identified and quantified with high confidence. Bioinformatic analyses of this proteome revealed substantial alterations in protein profiles during the life cycle, particularly in the transition from the free-living to the parasitic phase, and key groups of proteins involved specifically in feeding, digestion, metabolism, development, parasite-host interactions (including immunomodulation), structural remodelling of the body wall and adaptive processes during parasitism. This proteomic data set will facilitate future molecular, biochemical and physiological investigations of H. contortus and related nematodes, and the discovery of novel intervention targets against haemonchosis.
Distinguishing Echinococcus granulosus sensu stricto genotypes G1 and G3 with confidence: A practical guide
Publisher: Elsevier BV
Date: 10-2018
Screening for haplotypic variability within Oesophagostomum bifurcum (Nematoda) employing a single-strand conformation polymorphism approach
Publisher: Elsevier BV
Date: 06-2002
Abstract: Genetic markers in the mitochondrial genome have proven useful for population genetic studies because of their maternal inheritance and relatively high evolutionary rates. In this study, we exploited the high resolution capacity of PCR-coupled single-strand conformation polymorphism (SSCP) to screen for sequence variation in part of the cytochrome c oxidase subunit 1 gene (p cox 1) among in iduals of the parasitic nematode, Oesophagostomum bifurcum from human or Mona monkey hosts from Africa. SSCP analysis revealed distinct profiles among some of the in iduals, and subsequent sequence analysis of representative s les defined 10 different haplotypes. For comparative purposes, the p cox 1 sequences for representatives of four other species of Oesophagostomum from livestock were included. While there were high levels (11.5-13.7%) of sequence difference among the latter species, there was no fixed nucleotide difference between O. bifurcum in iduals from humans and those from monkeys. The data support the proposal that O. bifurcum from the two primate hosts represents a single species and that the haplotypic variability in p cox 1 represents population variation. The results reinforce the usefulness of the SSCP-sequencing approach for studying genetic variation in nematode populations using mitochondrial markers.
Transcriptional alterations in Caenorhabditis elegans following exposure to an anthelmintic fraction of the plant Picria fel-terrae Lour.
Publisher: Springer Science and Business Media LLC
Date: 25-04-2019
More parasitic myositis cases in humans in Australia, and the definition of genetic markers for the causative agents as a basis for molecular diagnosis.
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.MEEGID.2016.06.026
Abstract: Since 1998, there have been six reported human cases of myositis in Australia, attributable to infection with the nematode Haycocknema perplexum. However, an unequivocal diagnosis of H. perplexum infection and associated disease has been seriously compromised by a lack of molecular markers for this nematode. Here, we report new cases of disseminated myositis in two male patients from the states of Queensland and Tasmania in Australia, respectively genetically characterize the causative agent from each case and, also establish a PCR-based sequencing approach as a tool to support the diagnosis of future cases and to underpin epidemiological studies.
Elucidating the identity of Anisakis larvae from a broad range of marine fishes from the Yellow Sea, China, using a combined electrophoretic‐sequencing approach
Publisher: Wiley
Date: 2010
Abstract: Larval nematodes were collected from marine fishes from the Yellow Sea, China. Specimens (n=1731) of Anisakis type I from 311 fishes (representing 40 species) were each identified based on morphological characters. From the genomic DNA from in idual specimens, a region of nuclear ribosomal DNA was lified by PCR, followed by digestion with restriction endonuclease HinfI, TaqI or HhaI. Subsequently, the ITS-1 and ITS-2 regions of selected s les were sequenced. The results revealed three species of Anisakis, namely Anisakis pegreffii (n=1709), A. typica (n=3) and a genotype (n=19) proposed, also based on comparison with previous studies, to be a "hybrid" between A. pegreffii and A. simplex sensu stricto. Thus, A. pegreffii was the dominant species, accounting for 98.7% of the total number of specimens examined herein. This is the first report of A. typica and the "hybrid" genotype from fishes from the Yellow Sea. This study provides important basic information on Anisakis in this region and suggests that the genus Anisakis has substantial host and geographical distributions.
A recombinant antigen with potential for serodiagnosis of Echinococcus granulosus infection in dogs
Publisher: Elsevier BV
Date: 11-1990
DOI: 10.1016/0020-7519(90)90033-J
Abstract: Antibodies specific for Echinococcus granulosus were affinity purified from dog serum on transfer blots containing putative serodiagnostic antigens. These antibodies and serum pools derived from dogs with E. granulosus infections were used to screen a lambda gt11 cDNA library constructed using E. granulosus protoscolex mRNA. Nine definitive antigenic clones were isolated and characterized, of which one (c10P1) gave strong specific reactions in plaque immunoassay with sera from E. granulosus infected dogs. These clones were all subcloned into the plasmid vector pGEX-1. Antigenicity of clones was confirmed in colony immunoassay and/or immunoblot. Glutathione S-transferase (GST) fusion proteins of in idual subclones were produced in Escherichia coli, purified by affinity chromatography and evaluated in ELISA using sera from dogs with infections of E. granulosus, Taenia spp. or nematodes, and helminth-free dog sera. The GST fusion protein 10P1 showed a specificity of 100% in ELISA for diagnosis of E. granulosus infection in dogs despite its relatively low sensitivity. Further investigations aim to identify additional recombinant antigens and test 10P1 expressed in alternative expression systems to increase diagnostic sensitivity of the ELISA.
Assessment of a serological test for the detection of Echinococcus granulosus infection in dogs in Kenya
Publisher: Elsevier BV
Date: 05-1990
Improved molecular diagnostic tools for human hookworms
Publisher: Informa UK Limited
Date: 2009
Abstract: Blood-feeding hookworms are parasitic roundworms (i.e., nematodes) of major socioeconomic importance, affecting millions of people worldwide. Despite their impact on human health, little attention has been paid to improving practical methods of diagnosis. The genetic characterization of hookworms and specific diagnosis of their infections are central to elucidating the ecology and epidemiology of these parasites as well as the control of the disease they cause. Traditional coprodiagnostic methods have major limitations. This article summarizes progress in the development of molecular-analytical and -diagnostic tools, and discusses the need to establish practical 'laboratory' and 'field' assays for use in integrated hookworm prevention and control programs.
The mitogenome of Halotydeus destructor (Tucker) and its relationships with other trombidiform mites as inferred from nucleotide sequences and gene arrangements
Publisher: Wiley
Date: 22-09-2021
DOI: 10.1002/ECE3.8133
Abstract: The redlegged earth mite, Halotydeus destructor (Tucker, 1925: Trombidiformes, Eupodoidea, Penthaleidae), is an invasive mite species. In Australia, this mite has become a pest of winter pastures and grain crops. We report the complete mitogenome for H. destructor , the first to represent the family Penthaleidae, superfamily Eupodoidea. The mitogenome of H. destructor is 14,691 bp in size, and has a GC content of 27.87%, 13 protein‐coding genes, two rRNA genes, and 22 tRNA genes. We explored evolutionary relationships of H. destructor with other members of the Trombidiformes using phylogenetic analyses of nucleotide sequences and the order of protein‐coding and rRNA genes. We found strong, consistent support for the superfamily Tydeoidea being the sister taxon to the superfamily Eupodoidea based on nucleotide sequences and gene arrangements. Moreover, the gene arrangements of Eupodoidea and Tydeoidea are not only identical to each other but also identical to that of the hypothesized arthropod ancestor, showing a high level of conservatism in the mitogenomic structure of these mite superfamilies. Our study illustrates the utility of gene arrangements for providing complementary information to nucleotide sequences with respect to inferring the evolutionary relationships of species within the order Trombidiformes. The mitogenome of H. destructor provides a valuable resource for further population genetic studies of this important agricultural pest. Given the co‐occurrence of closely related, morphologically similar Penthaleidae mites with H. destructor in the field, a complete mitogenome provides new opportunities to develop metabarcoding tools to study mite ersity in agro‐ecosystems. Moreover, the H. destructor mitogenome fills an important taxonomic gap that will facilitate further study of trombidiform mite evolution.
Molecular analysis of Cryptosporidium from cattle from five states of Peninsular Malaysia
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.MCP.2016.01.002
Abstract: Despite the importance of the cattle industry in Malaysia, there are very few studies of the ersity and public health significance of bovine cryptosporidiosis in this country. In the present study, we used a PCR-based approach to detect and genetically characterize Cryptosporidium DNA in faecal s les from a cohort of 215 asymptomatic cattle (of different ages) from six farms from five states of Peninsular Malaysia. Cattle on four of the six farms were test-positive for Cryptosporidium, with an overall prevalence of 3.2%. Cryptosporidium bovis and Cryptosporidium ryanae were detected in two (0.9%) and five (2.3%) s les tested this low prevalence likely relates to the age of the cattle tested, as most (73%) of the s les tested originated from cattle that were ≥2 years of age. Future studies should investigate the zoonotic potential of Cryptosporidium in pre-weaned and weaned calves in rural communities of Malaysia.
Phylogenetic relationships of species of the oesophageal parasitic nematode genera Cyclostrongylus and Spirostrongylus (Strongyloidea: Chabertiidae: Cloacininae) with their wallaby hosts (Marsupialia: Macropodidae)
Publisher: Elsevier BV
Date: 04-2016
DOI: 10.1016/J.MCP.2016.01.004
Abstract: A phylogeny for seven species of Cyclostrongylus and the monotypic genus Spirostrongylus (Nematoda: Chabertiidae), all highly host specific parasites of the oesophagi of wallabies (Marsupialia: Macropodidae), was constructed using sequence data for the first and second internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA. There was no evidence for co-speciation, or for the sympatric or synxenic speciation of Cyclostrongylus alatus and Cyclostrongylus perplexus, both of which are parasites of Macropus rufogriseus. Rather, host switching, correlating with geographical distributions, appeared to provide some explanation of the pattern of speciation observed.
Molecular investigation of Cryptosporidium and Giardia in pre- and post-weaned calves in Hubei Province, China.
Publisher: Springer Science and Business Media LLC
Date: 25-10-2017
Myophilin of Echinococcus granulosus: isoforms and phosphorylation by protein kinase C
Publisher: Cambridge University Press (CUP)
Date: 08-1997
DOI: 10.1017/S003118209700108X
Abstract: Myophilin is a muscle-associated antigen of the taeniid cestode Echinococcus granulosus . This protein shows a high amino acid sequence homology with calponins and calponin-like proteins, which are proposed to be associated with the regulation of smooth muscle contraction. In order to provide supportive evidence for a relationship between these proteins, we characterized myophilin using electrophoretic, biochemical and molecular biological approaches. Two-dimensional protein electrophoretic separation of E. granulosus larval proteins defined 4 isoelectric isoforms of myophilin (α, β, γ and δ), which appeared to be a consequence of post-translational modification of a single gene product. It was also demonstrated biochemically that E. granulosus myophilin undergoes specific phosphorylation in vitro by protein kinase C (PKC). Finally, myophilin homologues were identified in extracts of Taenia hydatigena and T. ovis by immunoblot. A partial cDNA of the closely related species, E. multilocularis , was isolated by cloning procedures and showed 99% homology with the E. granulosus myophilin gene. The similarities of E. granulosus myophilin with calponins in their tissue localization, protein isoform patterns, ability to be phosphorylated in vitro by PKC, and the relatively conserved nature of the protein among related parasites suggest that myophilin may be associated with smooth muscle contraction.
Molecular taxonomic, diagnostic and genetic studies of parasitic helminths
Publisher: Elsevier BV
Date: 07-2001
Probing function and structure of trehalose‐6‐phosphate phosphatases from pathogenic organisms suggests distinct molecular groupings
Publisher: Wiley
Date: 18-11-2016
Characterization of Taenia madoquae and Taenia regis from carnivores in Kenya using genetic markers in nuclear and mitochondrial DNA, and their relationships with other selected taeniids.
Publisher: Elsevier BV
Date: 10-2007
DOI: 10.1016/J.MCP.2007.05.003
Abstract: In the present study, we have extended earlier taxonomic, biochemical and experimental investigations to characterize two species of Taenia from carnivores in Kenya by use of the sequences of a variable domain (D1) of nuclear ribosomal DNA and the cytochrome c oxidase subunit 1 and NADH dehydrogenase 1 genes of mitochondrial DNA. Emphasis was placed on the characterization of Taenia madoquae from the silver-backed jackal (Canis mesomelas) and Taenia regis from the lion (Panthera leo), given the previous absence of any DNA sequence data for them, and on assessing their genetic relationships with socioeconomically important taeniids. The study showed that T. regis was genetically most closely related to T. hydatigena, and T. madoquae to T. serialis, T. multiceps or T. saginata. The present findings provide a stimulus for future work on the systematic relationships and epidemiology of lesser-known taeniid cestodes in Africa and other continents, employing mitochondrial sequence data sets.
Phylogenomic and biogeographic reconstruction of the Trichinella complex
Publisher: Springer Science and Business Media LLC
Date: 02-2016
DOI: 10.1038/NCOMMS10513
Abstract: Trichinellosis is a globally important food-borne parasitic disease of humans caused by roundworms of the Trichinella complex. Extensive biological ersity is reflected in substantial ecological and genetic variability within and among Trichinella taxa, and major controversy surrounds the systematics of this complex. Here we report the sequencing and assembly of 16 draft genomes representing all 12 recognized Trichinella species and genotypes, define protein-coding gene sets and assess genetic differences among these taxa. Using thousands of shared single-copy orthologous gene sequences, we fully reconstruct, for the first time, a phylogeny and biogeography for the Trichinella complex, and show that encapsulated and non-encapsulated Trichinella taxa erged from their most recent common ancestor ∼21 million years ago (mya), with taxon ersifications commencing ∼10−7 mya.
Common secondary structures for the second internal transcribed spacer pre-rRNA of two subfamilies of trichostrongylid nematodes
Publisher: Elsevier BV
Date: 11-1998
DOI: 10.1016/S0020-7519(98)00129-5
Abstract: Sequences of the second internal transcribed spacer ribosomal DNA for the parasitic trichostrongylid nematodes Trichostrongylus probolurus, Trichostrongylus rugatus and Camelostrongylus mentulatus were compared with previously published sequences for five other species within the genus Trichostrongylus. The secondary structures of the second internal transcribed spacer pre-rRNA for these nematodes were predicted using an energy minimisation method. The results indicate that a common secondary structure of the second internal transcribed spacer of these nematodes is maintained despite distinct differences in primary sequence between species. Sequence differences among Trichostrongylus species ranged from 1.3 to 7.6%, but each species differed by 22-26% in sequence when compared with C. mentulatus which belongs to a different subfamily.
Mutation scanning methods for the analysis of parasite genes
Publisher: Elsevier BV
Date: 12-1997
DOI: 10.1016/S0020-7519(97)00131-8
Abstract: Molecular variation is widespread in parasite populations, and its analysis has important implications for studying aspects relating to the function and organisation of genes, and the taxonomy, phylogeny and population genetics of parasites. This article reviews some PCR-based mutation scanning techniques that have advantages over currently used DNA methods for the analysis of genetic variation in parasites. The review is technical and describes briefly the principles of relevant techniques, examines some of their advantages and disadvantages and gives several ex les for possible applications.
Intraspecific and interspecific variation in the second internal transcribed spacer sequence for Metastrongylus (Nematoda: Metastrongyloidea) detected by high resolution PCR-linked restriction fragmen
Publisher: Elsevier BV
Date: 12-1999
DOI: 10.1016/S0020-7519(99)00149-6
Abstract: Metastrongylus species are important parasites of free-range pigs and wild boar, but little is known about the genetic make-up of natural populations. This study was undertaken to examine sequence variation in the internal transcribed spacer 2 of ribosomal DNA within and among three species of Metastrongylus using PCR-linked restriction fragment length polymorphism analysis. In contrast to many other species of bursate nematodes, significant intraspecific variation was detected in restriction fragment length polymorphism profiles among in idual worms. In spite of this, it was possible to identify the three species by their distinctive restriction profiles. The findings suggest that the internal transcribed spacer 2 region should be useful for analysing population variation within Metastrongylus species.
The benefits of analysing complete mitochondrial genomes: Deep insights into the phylogeny and population structure of Echinococcus granulosus sensu lato genotypes G6 and G7
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.MEEGID.2018.06.016
Abstract: Cystic echinococcosis (CE) is a zoonotic disease caused by the larval stage of the species complex Echinococcus granulosus sensu lato. Within this complex, genotypes G6 and G7 have been frequently associated with human CE worldwide. Previous studies exploring the genetic variability and phylogeography of genotypes G6 and G7 have been based on relatively short mtDNA sequences, and the resolution of these studies has often been low. Moreover, using short sequences, the distinction between G6 and G7 has in some cases remained challenging. The aim here was to sequence complete mitochondrial genomes (mitogenomes) to obtain deeper insight into the genetic ersity, phylogeny and population structure of genotypes G6 and G7. We sequenced complete mitogenomes of 94 s les collected from 15 different countries worldwide. The results demonstrated that (i) genotypes G6 and G7 can be clearly distinguished when mitogenome sequences are used (ii) G7 is represented by two major haplogroups, G7a and G7b, the latter being specific to islands of Corsica and Sardinia (iii) intensive animal trade, but also geographical isolation, have likely had the largest impact on shaping the genetic structure and distribution of genotypes G6 and G7. In addition, we found phylogenetically highly ergent haplotype from Mongolia (Gmon), which had a higher affinity to G6.
Apoptosis in schistosomes: Toward novel targets for the treatment of schistosomiasis
Publisher: Elsevier BV
Date: 02-2014
Abstract: Schistosomiasis is one of the world's major neglected tropical diseases. Recent advances in schistosome genomics and transcriptomics have identified components of an intrinsic, B cell lymphoma-2 (Bcl-2)-regulated apoptotic cell death pathway. Molecular characterization of this pathway demonstrates its similarity to that in mammals. Gene expression and functional data indicate that apoptosis is active throughout the lifecycle. Moreover, drugs that activate apoptosis in human cells kill schistosome cells, raising the prospect of developing new treatments against schistosomiasis of humans. The development of new drugs is increasingly important in the face of the potential for resistance to currently available treatments, and the lack of an effective vaccine.
Drug target prediction and prioritization: using orthology to predict essentiality in parasite genomes
Publisher: Springer Science and Business Media LLC
Date: 03-04-2010
Abstract: New drug targets are urgently needed for parasites of socio-economic importance. Genes that are essential for parasite survival are highly desirable targets, but information on these genes is lacking, as gene knockouts or knockdowns are difficult to perform in many species of parasites. We examined the applicability of large-scale essentiality information from four model eukaryotes, Caenorhabditis elegans, Drosophila melanogaster, Mus musculus and Saccharomyces cerevisiae , to discover essential genes in each of their genomes. Parasite genes that lack orthologues in their host are desirable as selective targets, so we also examined prediction of essential genes within this subset. Cross-species analyses showed that the evolutionary conservation of genes and the presence of essential orthologues are each strong predictors of essentiality in eukaryotes. Absence of paralogues was also found to be a general predictor of increased relative essentiality. By combining several orthology and essentiality criteria one can select gene sets with up to a five-fold enrichment in essential genes compared with a random selection. We show how quantitative application of such criteria can be used to predict a ranked list of potential drug targets from Ancylostoma caninum and Haemonchus contortus - two blood-feeding strongylid nematodes, for which there are presently limited sequence data but no functional genomic tools. The present study demonstrates the utility of using orthology information from multiple, erse eukaryotes to predict essential genes. The data also emphasize the challenge of identifying essential genes among those in a parasite that are absent from its host.
First genetic analysis of Cryptosporidium from humans from Tasmania, and identification of a new genotype from a traveller to Bali
Publisher: Wiley
Date: 28-07-2014
Abstract: Little is known about the molecular composition of Cryptosporidium species from humans living in the insular state of Tasmania, Australia. In the present study, we genetically characterized 82 s les of Cryptosporidium from humans following conventional coproscopic testing in a routine, diagnostic laboratory. Using a PCR-coupled single-strand conformation polymorphism (SSCP) technique, targeting portions of the small subunit rRNA (SSU), and 60 kDa glycoprotein (gp60) loci, we identified two species of Cryptosporidium, including C. hominis (subgenotypes IbA10G2, IdA16, IeA12G3T3, and IfA19G1) and C. parvum (IIaA16G1R1 and IIaA18G3), and a new operational taxonomic unit (OTU) that genetically closely resembled C. wrairi. This OTU was further characterized using markers in the actin, Cryptosporidium oocyst wall protein (COWP), and 70 kDa heat shock protein (hsp70) genes. This study provides the first characterization of species and genotypes of Cryptosporidium from Tasmania, and presents clear genetic evidence, using five independent genetic loci, for a new genotype or species of Cryptosporidium in a Tasmanian person with a recent history of travelling to Bali, Indonesia. It would be interesting to undertake detailed molecular-based studies of Cryptosporidium in Indonesia and neighbouring countries, in conjunction with morphological and experimental investigations of new genotypes.
Evidence that Transcriptional Alterations in Sarcoptes scabiei Are under Tight Post-Transcriptional (microRNA) Control
Publisher: MDPI AG
Date: 26-08-2022
DOI: 10.3390/IJMS23179719
Abstract: Here, we explored transcriptomic differences among early egg (Ee), late egg (Le) and adult female (Af) stages of the scabies mite, Sarcoptes scabiei, using an integrative bioinformatic approach. We recorded a high, negative correlation between miRNAs and genes with decreased mRNA transcription between the developmental stages, indicating substantial post-transcriptional repression we also showed a positive correlation between miRNAs and genes with increased mRNA transcription, suggesting indirect post-transcriptional regulation. The alterations in mRNA transcription between the egg and adult female stages of S. scabiei were inferred to be linked to metabolism (including carbohydrate and lipid degradation, amino acid and energy metabolism), environmental information processing (e.g., signal transduction and signalling molecules), genetic information processing (e.g., transcription and translation) and/or organismal systems. Taken together, these results provide insight into the transcription of this socioeconomically important parasitic mite, with a particular focus on the egg stage. This work encourages further, detailed laboratory studies of miRNA regulation across all developmental stages of S. scabiei and might assist in discovering new intervention targets in the egg stage of S. scabiei.
Molecular biology of reproduction and development in parasitic nematodes: progress and opportunities
Publisher: Elsevier BV
Date: 02-2004
Dictyocaulus viviparus genome, variome and transcriptome elucidate lungworm biology and support future intervention
Publisher: Springer Science and Business Media LLC
Date: 09-02-2016
DOI: 10.1038/SREP20316
Abstract: The bovine lungworm, Dictyocaulus viviparus (order Strongylida), is an important parasite of livestock that causes substantial economic and production losses worldwide. Here we report the draft genome, variome and developmental transcriptome of D. viviparus . The genome (161 Mb) is smaller than those of related bursate nematodes and encodes fewer proteins (14,171 total). In the first genome-wide assessment of genomic variation in any parasitic nematode, we found a high degree of sequence variability in proteins predicted to be involved host-parasite interactions. Next, we used extensive RNA sequence data to track gene transcription across the life cycle of D. viviparus and identified genes that might be important in nematode development and parasitism. Finally, we predicted genes that could be vital in host-parasite interactions, genes that could serve as drug targets and putative RNAi effectors with a view to developing functional genomic tools. This extensive, well-curated dataset should provide a basis for developing new anthelmintics, vaccines and improved diagnostic tests and serve as a platform for future investigations of drug resistance and epidemiology of the bovine lungworm and related nematodes.
Female-specific genomic pcr sequences from Schistosoma mansoni as probes for hybridization histochemistry
Publisher: Elsevier BV
Date: 05-1993
DOI: 10.1016/0020-7519(93)90018-T
Abstract: Rapid methods for sexing single larval or egg stages of schistosomes have been difficult to establish. Such methods would be of value for assessing changes in sex ratios at different stages of the life cycle and studying diseases processes of schistosomiasis. We describe the use of hybridization histochemistry for identification of female eggs of Schistosoma mansoni in sections of infected mouse liver using a highly repetitive genomic DNA sequence generated by the polymerase chain reaction with primers spanning a known female-specific sequence (W1) of S. mansoni. In an initial study, approximately half of the eggs in each liver section from mice infected for 50 days labelled heavily with this probe. Further studies will evaluate the sensitivity and specificity of the probe on clonal populations (either male or female) or larvae in host tissue.
Assessment of the nematocidal activity of metallocenyl analogues of monepantel
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6DT03376H
Abstract: Ferrocenyl and ruthenocenyl analogues of the nematocidal drug monepantel show organometallic-dependent activity against Haemonchus contortus and Trichostrongylus colubriformis .
Characterisation of Ascaris from human and pighosts by nuclear ribosomal DNA sequencesfn1fn1Note: Nucleotide sequence data reported in this paperare available in the embl, GenBankTM and DDJBdatabases
Publisher: Elsevier BV
Date: 03-1999
DOI: 10.1016/S0020-7519(98)00226-4
Abstract: The sequences of the nuclear ribosomal DNA region spanning the first internal transcribed spacer, the 5.8S rRNA gene and the second internal transcribed spacer were determined for Ascaris s les from pigs and humans from different geographical regions. The sequences of the 5.8S gene and the second internal transcribed spacer were the same for all s les examined, whereas all Ascaris s les from humans had six (1.3%) nucleotide differences in the first internal transcribed spacer compared with those from pigs. These differences provided some support for the existence of separate species of Ascaris or population variation within this genus. Using a nucleotide difference within a site for the restriction enzyme HaeIII, a PCR-linked restriction fragment length polymorphism method was established which allowed the delineation of the Ascaris s les from pigs and humans used herein. Exploiting the sequence differences in the first internal transcribed spacer, a PCR-based single-strand conformation polymorphism method was established for future analysis of the genetic structure of pig and human Ascaris populations in sympatric and allopatric zones.
Molecular evidence for cryptic species within Cylicostephanus minutus (Nematoda: Strongylidae).
Publisher: Elsevier BV
Date: 02-1999
DOI: 10.1016/S0020-7519(98)00203-3
Abstract: The nucleotide sequences of the first and second internal transcribed spacers of nuclear ribosomal DNA were determined for adults of Cylicostephanus minutus from different geographical origins. The lengths of first and second internal transcribed spacer sequences ranged from 370 to 372bp and 215 to 216bp, respectively. Pairwise sequence comparisons revealed that some in iduals of C. minutus had identical first and second internal transcribed spacer sequences, whereas others differed by 3.0% and 7.4% in their first and second transcribed spacers, respectively. Some in iduals with sequence differences originated from the same host. The levels of difference within C. minutus were higher than that between the morphologically distinct species, Cylicostephanus goldi and Cylicostephanus longibursatus (0.8% for the first internal transcribed spacer and 3.8% for the second internal transcribed spacer). The data provide support for the proposal that C. minutus represents a complex of at least two species. In order to study the population genetic structure of C. minutus, a PCR-linked single-strand conformation polymorphism technique was also established.
Improved strategy for the curation and classification of kinases, with broad applicability to other eukaryotic protein groups
Publisher: Springer Science and Business Media LLC
Date: 05-2018
DOI: 10.1038/S41598-018-25020-8
Abstract: Despite the substantial amount of genomic and transcriptomic data available for a wide range of eukaryotic organisms, most genomes are still in a draft state and can have inaccurate gene predictions. To gain a sound understanding of the biology of an organism, it is crucial that inferred protein sequences are accurately identified and annotated. However, this can be challenging to achieve, particularly for organisms such as parasitic worms (helminths), as most gene prediction approaches do not account for substantial phylogenetic ergence from model organisms, such as Caenorhabditis elegans and Drosophila melanogaster , whose genomes are well-curated. In this paper, we describe a bioinformatic strategy for the curation of gene families and subsequent annotation of encoded proteins. This strategy relies on pairwise gene curation between at least two closely related species using genomic and transcriptomic data sets, and is built on recent work on kinase complements of parasitic worms. Here, we discuss salient technical aspects of this strategy and its implications for the curation of protein families more generally.
Toward next-generation sequencing of mitochondrial genomes — Focus on parasitic worms of animals and biotechnological implications
Publisher: Elsevier BV
Date: 2010
DOI: 10.1016/J.BIOTECHADV.2009.11.002
Abstract: Helminths (worms) include parasitic nematodes (roundworms) and platyhelminths (flatworms). These worms are abundant, and many of them are of agricultural, aquacultural, veterinary and medical importance and cause substantial socioeconomic losses worldwide. The genetic characterization of parasitic nematodes using advanced molecular tools is central to the diagnosis of infections and the control of parasitism. The accurate analysis of genetic variation also underpins studies of their taxonomy, epidemiology and evolutionary history. Although the nuclear genome contains suitable genetic markers (e.g., in ribosomal DNA) for the identification of many species, the large size and high variability of the mt genome consistently provides a rich source of such markers for informative systematic and epidemiological studies both within and among species. There is significant value in establishing a practical platform for the rapid sequencing, annotation and analysis of mt genomic datasets to underpin such fundamental and applied studies of parasitic worms (= helminths). In the last decade, there have been some important advances in the mt genomics of helminths, but next-generation sequencing (NGS) technologies now provide opportunities for high throughput sequencing, assembly and annotation. In this article, we provide a background on mt genomics, cover technological challenges and recent advances, and provide a perspective on future mt genome research of parasitic helminths and its fundamental scientific and biotechnological implications.
Quantitative lipidomic analysis of Ascaris suum
Publisher: Public Library of Science (PLoS)
Date: 02-12-2020
DOI: 10.1371/JOURNAL.PNTD.0008848
Abstract: Ascaris is a soil-transmitted nematode that causes ascariasis, a neglected tropical disease affecting predominantly children and adolescents in the tropics and subtropics. Approximately 0.8 billion people are affected worldwide, equating to 0.86 million disability-adjusted life-years (DALYs). Exploring the molecular biology of Ascaris is important to gain a better understanding of the host-parasite interactions and disease processes, and supports the development of novel interventions. Although advances have been made in the genomics, transcriptomics and proteomics of Ascaris , its lipidome has received very limited attention. Lipidomics is an important sub-discipline of systems biology, focused on exploring lipids profiles in tissues and cells, and elucidating their biological and metabolic roles. Here, we characterised the lipidomes of key developmental stages and organ systems of Ascaris of porcine origin via high throughput LC-MS/MS. In total, 500 lipid species belonging to 18 lipid classes within three lipid categories were identified and quantified–in precise molar amounts in relation to the dry weight of worm material–in different developmental stages/sexes and organ systems. The results showed substantial differences in the composition and abundance of lipids with key roles in cellular processes and functions (e.g. energy storage regulation and membrane structure) among distinct stages and among organ systems, likely reflecting differing demands for lipids, depending on stage of growth and development as well as the need to adapt to constantly changing environments within and outside of the host animal. This work provides the first step toward understanding the biology of lipids in Ascaris , with possibilities to work toward designing new interventions against ascariasis.
Sequence differences in the internal transcribed spacer ribosomal DNA among four species of hookworm (Ancylostomatoidea: Ancylostoma)1Note: Nucleotide sequence data reported in this paper are availabl
Publisher: Elsevier BV
Date: 12-1999
AFLP fingerprinting for the analysis of genetic diversity within Necator americanus
Publisher: Elsevier BV
Date: 10-2006
DOI: 10.1016/J.MCP.2006.03.004
Abstract: In the present study, we utilised the method of AFLP to screen for genetic variation within and among in iduals of the blood-feeding human hookworm Necator americanus (Nematoda) from Africa, Asia and South America. A total of 45 adult worms (i.e. 20 from Ghana, 16 from Colombia and 9 from Nepal) were subjected to analysis using the restriction enzyme rimer combination HindIII+AG/BglII+AC. Cluster analysis ided N. americanus into multiple, genetically distinct groups, consistent with previous findings using ribosomal and mitochondrial DNA data sets. The results demonstrated the usefulness of AFLP fingerprinting for establishing genetic variation within N. americanus and reinforce its applicability to other parasitic helminths of human and/or veterinary health importance.
Survey of intestinal parasites in pigs from intensive farms in Guangdong Province, People's Republic of China
Publisher: Elsevier BV
Date: 02-2005
DOI: 10.1016/J.VETPAR.2004.09.030
Abstract: The prevalence of intestinal parasites was investigated in intensive pig farms in Guangdong Province, China between July 2000 and July 2002. Faecal s les from 3636 pigs (both sexes and five age groups) from 38 representative intensive pig farms employing different parasite control strategies were examined for the presence of helminth ova and protozoan oocysts, cysts and/or trophozoites using standard techniques. Of the 3636 pigs s led, 209 (5.7%) were infected with Trichuris suis, 189 (5.2%) with Ascaris, 91 (2.5%) with Oesophagostomum spp., 905 (24.9%) with coccidia (Eimeria spp. and/or Isospora suis) and 1716 (47.2%) with Balantidium coli. These infected pigs were mainly from farms without a strategic anti-parasite treatment regime. Concurrent infection of multiple parasites was common, and T. suis was the most common nematode infecting breeding, young and mature pigs. The results of the present investigation provide relevant 'base-line' data for assessing the effectiveness of control strategies against intestinal parasitism in intensively raised pigs in Guangdong Province, China.
Cryptosporidium viatorum from the native Australian swamp rat Rattus lutreolus - An emerging zoonotic pathogen?
Publisher: Elsevier BV
Date: 04-2018
MicroRNAs of Toxocara canis and their predicted functional roles
Publisher: Springer Science and Business Media LLC
Date: 23-04-2016
Comparative transcriptomic analyses of male and female adult Toxocara canis
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.GENE.2016.11.024
Abstract: Toxocariasis is an important, neglected zoonosis caused mainly by Toxocara canis. Although our knowledge of helminth molecular biology is improving through completed draft genome projects, there is limited detailed information on the molecular biology of Toxocara species. Here, transcriptomic sequencing of male and female adult T. canis and comparative analyses were conducted. For each sex, two-thirds (66-67%) of quality-filtered reads mapped to the gene set of T. canis, and at least five reads mapped to each of 16,196 (87.1%) of all 18,596 genes, and 321 genes were specifically transcribed in female and 1467 in male T. canis. Genes differentially transcribed between the two sexes were identified, enriched biological processes and pathways linked to these genes established, and molecules associated with reproduction and development predicted. In addition, small RNA pathways involved in reproduction were characterized, but there was no evidence for piwi RNA pathways in adult T. canis. The results of this transcriptomic study should provide a useful basis to support investigations of the reproductive biology of T. canis and related nematodes.
Genetic variation within and among species of Cloacina (Strongyloidea: Cloacinine) from the swamp wallaby, Wallabia bicolor (Marsupialia: Macropodidae)
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.MEEGID.2014.09.031
Abstract: This study examined genetic variation within and among species of Cloacina found in the sw wallaby (Wallabia bicolor) collected at different localities along the eastern coast of Australia, and evaluated geographical distance as a potential driver for genetic variation. The first and second internal transcribed spacers (ITS-1 and ITS-2, respectively) of the nuclear ribosomal DNA were used to characterize in iduals of 11 morphospecies of Cloacina that parasitize W. bicolor. The results of the molecular analyses revealed multiple genotypes for the nine morphospecies of Cloacina (i.e. Cloacina annulata, Cloacina edwardsi, Cloacina eos, Cloacina gallardi, Cloacina mawsonae, Cloacina papillata, Cloacina papillatissima, Cloacina pollux, and Cloacina wallabiae) for which multiple in iduals were available for analysis. However, phylogenetic analyses of the sequence data revealed that for each morphospecies, there was no sub ision of in iduals into distinct clades based on geographical region from which they were collected. Additional studies are needed to determine the drivers of genetic variation in cloacinid nematodes, and hence increase our understanding of the ersity of parasitic nematodes in macropodid marsupials.
The conserved zinc finger protein VAB-23 is an essential regulator of epidermal morphogenesis in Caenorhabditis elegans
Publisher: Elsevier BV
Date: 12-2009
DOI: 10.1016/J.YDBIO.2009.09.036
Abstract: Caenorhabditis elegans is an excellent model to observe cell movements and shape changes during the morphogenesis of the egg-shaped embryo into an elongated tube-like larva. Although much is known about the structural determinants involved in epidermal morphogenesis, relatively little is known about the transcriptional and post-transcriptional regulatory networks involved. Here, we describe the identification and functional characterization of the novel nuclear protein VAB-23, which belongs to a conserved protein family found in all metazoans. C. elegans VAB-23 is essential for ventral closure and elongation of the embryo. Time-lapse analysis indicates that VAB-23 is required for the formation of proper cell contacts between contralateral pairs of ventral epidermal cells. Tissue-specific rescue experiments reveal a function of VAB-23 in ventral neuroblasts that control the enclosure of the embryo by the overlaying epidermal cells. Finally, we provide evidence suggesting a role of VAB-23 in post-transcriptional gene regulation. We thus propose that VAB-23 regulates the expression of multiple secreted guidance cues in ventral neuroblasts that direct the migration of the overlaying epidermal cells. Members of the VAB-23 family may perform similar functions during morphogenesis in other metazoans.
The specific identification of anisakid larvae from fishes from the Yellow Sea, China, using mutation scanning-coupled sequence analysis of nuclear ribosomal DNA
Publisher: Elsevier BV
Date: 10-2007
DOI: 10.1016/J.MCP.2007.05.004
Abstract: Nematodes of the family Anisakidae parasitize fish, mammals, birds and reptiles, with the larval stages of some species causing severe clinical disease in humans. Therefore, the accurate identification of anisakid nematodes is a key component of disease surveillance and control. An epidemiological survey of 123 fishes comprising eight different species from the Yellow Sea in China revealed that more than 25% of fish were infected with the larvae of anisakids, 200 third-stage larvae (L3s) were collected from fish and then subjected to morphological and molecular study. Larvae identified as Anisakis type I (n=197) and Hysterothylacium sp. (n=3), based on morphological criteria were characterized genetically by mutation scanning, followed by targeted sequencing of the first and second internal transcribed spacers of nuclear ribosomal DNA. Comparison of the sequences obtained from a subset of 27 specimens with those available in public gene databases showed that all s les identified morphologically as Anisakis type I (n=197) were Anisakis pegreffii, whereas those identified as Hysterothylacium sp. (n=3) were Hysterothylacium aduncum. The approach used herein was an effective means of matching incompletely identifiable larval nematodes with identifiable reference sequences, and provides a basis for exploring the composition of populations of anisakid larvae in fish as well as their ecology, particularly their life cycles and transmission patterns.
Molecular characterization of selected dermatophytes and their identification by electrophoretic mutation scanning
Publisher: Wiley
Date: 10-2009
Abstract: Dermatophytes are fungi that can be contagious and cause infections in the keratinized skin of mammals, including humans. The etiological diagnosis of dermatophytosis relies on a combination of in vitro-culture and microscopic methods. Effective molecular tools could overcome the limitations of conventional methods of identification. In the present study, following phenetic identification as M. canis, M. fulvum, M. gypseum, T. mentagrophytes and T. terrestre, we genetically characterized key dermatophytes, employing the sequences of the first and second internal transcribed spacers of nuclear ribosomal DNA as well as part of the chitin synthase-1 gene, and assessed the utility of these DNA regions (based on levels of nucleotide variation within and among species/taxa) as markers for the classification of species and genotypes. Employing partial chitin synthase-1 gene as the marker, we also established a PCR-coupled SSCP approach as a diagnostic/analytical mutation-scanning tool. This tool should facilitate fundamental investigations of the ecology, epidemiology and population genetics of dermatophytes and, importantly, should assist in allowing a more rapid diagnosis of dermatophytoses in humans and other animals, thus overcoming the significant delays in targeted chemotherapy following diagnosis using conventional methods. (Nucleotide sequence data reported in this paper are available in the EMBL, GenBank and DDJB datadases under accession numbers FJ897707-FJ897713 (ITS-1), FJ897714-FJ897720 (ITS-2) and FJ897700-FJ897706 (pchs-1)).
Lack of intraspecific variation in the second Internal Transcribed Spacer (ITS-2) of Trichostrongylus colubriformis ribosomal DNA
Publisher: Elsevier BV
Date: 12-1993
DOI: 10.1016/0020-7519(93)90128-L
Abstract: The nucleotide sequence of the second internal transcribed spacer (ITS-2) was determined for three populations of the parasitic nematode Trichostrongylus colubriformis which differed in their susceptibility to benzimidazole anthelmintics and/or in their geographical origin. No intraspecific variation was found in the ITS-2 sequence, indicating that this region of rDNA is inadequate to discriminate between resistant and susceptible populations of T. colubriformis, but it may prove useful for distinguishing between species of Trichostrongylus.
Enterocytozoon bieneusi Genotypes in Cattle on Farms Located within a Water Catchment Area
Publisher: Wiley
Date: 19-11-2019
DOI: 10.1111/JEU.12696
Abstract: Enterocytozoon bieneusi is a microsporidian found in humans and other animals around the world. Investigations in some countries, such as the U.S., have indicated the importance of E. bieneusi as a zoonotic water- and food-borne pathogen. However, there is scant epidemiological information on E. bieneusi in animals in many countries including Australia. Here, we conducted the first molecular epidemiological study of E. bieneusi in farmed cattle in Victoria, Australia, to assess whether these bovids are carriers of "zoonotic" genotypes of E. bieneusi. A total of 471 in idual faecal s les were collected from calves of < 3 mo and of 3-9 mo of age. Genomic DNAs were extracted from in idual faecal s les and then subjected to nested PCR-based sequencing of the internal transcribed spacer (ITS) of nuclear ribosomal DNA to identify E. bieneusi and define genotypes. Enterocytozoon bieneusi was detected in 49 of the 471 s les (10.4%). An analysis of ITS sequence data revealed three known genotypes (BEB4, I, and J) and three novel genotypes (designated TAR_fc1 to TAR_fc3). Phylogenetic analysis showed that genotypes BEB4, I, J, TAR_fc1, and TAR_fc2 clustered with genotypes identified previously in humans, indicating that cattle are carriers of E. bieneusi with zoonotic potential.
First molecular characterisation of Cryptosporidium and Giardia from Bubalus bubalis (water buffalo) in Victoria, Australia
Publisher: Elsevier BV
Date: 12-2013
DOI: 10.1016/J.MEEGID.2013.07.019
Abstract: We conducted a molecular epidemiological survey of Cryptosporidium and Giardia from Bubalus bubalis (water buffalo) on two extensive farms (450 km apart) in Victoria, Australia. Faecal s les (n=476) were collected from different age groups of water buffalo at two time points (six months apart) and tested using a PCR-based mutation scanning-targeted sequencing-phylogenetic approach, employing markers within the small subunit of ribosomal RNA (designated pSSU) and triose phosphate isomerase (ptpi) genes. Based on pSSU data, Cryptosporidium parvum, Cryptosporidium bovis and Cryptosporidium genotypes 1, 2 (each 99% similar genetically to Cryptosporidium ryanae) and 3 (99% similar to Cryptosporidium suis) were detected in two (0.4%), one (0.2%), 38 (8.0%), 16 (3.4%) and one (0.2%) of the 476 s les tested, respectively. Using ptpi, Giardia duodenalis assemblages A and E were detected in totals of 56 (11.8%) and six (1.3%) of these s les, respectively. Cryptosporidium was detected on both farms, whereas Giardia was detected only on farm B, and both genera were detected in 1.5% of all s les tested. The study showed that water buffaloes on these farms excreted C. parvum and/or G. duodenalis assemblage A, which are consistent with those found in humans, inferring that these particular pathogens are of zoonotic significance. Future work should focus on investigating, in a temporal and spatial manner, the prevalence and intensity of such infections in water buffaloes in various geographical regions in Australia and in other countries.
Key strongylid nematodes of animals - Impact of next-generation transcriptomics on systems biology and biotechnology
Publisher: Elsevier BV
Date: 05-2012
DOI: 10.1016/J.BIOTECHADV.2011.08.016
Abstract: The advent and integration of high-throughput 'omic technologies (e.g., genomics, transcriptomics, proteomics and metabolomics) are becoming instrumental to assist fundamental explorations of the systems biology of organisms. In particular, these technologies now provide unique opportunities for global, molecular investigations of parasites. For ex le, studies of the transcriptomes (all transcripts in an organism, tissue or cell) of different species and/or developmental stages of parasitic nematodes provide insights into aspects of gene expression, regulation and function, which is a major step to understanding their biology. The purpose of this article was to review salient aspects of the systematics and biology of selected species of parasitic nematodes (particularly key species of the order Strongylida) of socio-economic importance, to describe conventional and advanced sequencing technologies and bioinformatic tools for large-scale investigations of the transcriptomes of these parasites and to highlight the prospects and implications of these explorations for developing novel methods of parasite intervention.
Identification of protein components of Echinococcus granulosus protoscolex antigens for specific serodiagnosis of E. granulosus infection in dogs
Publisher: Wiley
Date: 05-1989
DOI: 10.1111/J.1365-3024.1989.TB00666.X
Abstract: Proteins of Echinococcus granulosus protoscolex excretory/secretory or deoxycholate solubilized somatic antigens were radiolabelled with 125I and immunoprecipitated with sera from dogs naturally or experimentally infected with E. granulosus and various control dog sera. Analysis of immunoprecipitates was performed using one- and two-dimensional gel electrophoresis to identify antigenic protein components specific for E. granulosus. Using both electrophoretic techniques, a basic component of Mr 27,000 and an acidic component of Mr 94,000 were defined in both excretory/secretory and somatic protoscolex antigens, and were specifically identified by 95% and 62% of 21 sera from E. granulosus-infected dogs, respectively. An abundant component of Mr 35,000 was identified by 100% of these dogs, parts of which were E. granulosus specific. Results of this study should allow identification of specific recombinant antigens for routine serodiagnosis of E. granulosus infection in dogs.
Human cyclosporiasis
Publisher: Elsevier BV
Date: 07-2019
Harnessing Genomic Technologies to Explore the Molecular Biology of Liver Flukes-Major Implications for Fundamental and Applied Research
Publisher: Wiley
Date: 18-07-2012
Recent Progress in Transcriptomics of Key Gastrointestinal Nematodes of Animals - Fundamental Research Toward New Intervention Strategies
Publisher: Wiley
Date: 18-07-2012
Molecular and phylogenetic characterisation of Cryptosporidium from birds
Publisher: Elsevier BV
Date: 03-2001
DOI: 10.1016/S0020-7519(00)00164-8
Abstract: Avian isolates of Cryptosporidium species from different geographic locations were sequenced at two loci, the 18S rRNA gene and the heat shock gene (HSP-70). Phylogenetic analysis of the sequence data provided support for the existence of a new avian species of Cryptosporidium infecting finches and a second species infecting a black duck. The identity of Cryptosporidium baileyi and Cryptosporidium meleagridis as valid species was confirmed. Also, C. baileyi was identified in a number of isolates from the brown quail extending the host range of this species.
Use of a bioinformatic-assisted primer design strategy to establish a new nested PCR-based method for Cryptosporidium.
Publisher: Springer Science and Business Media LLC
Date: 23-10-2017
Characterisation of anisakid nematodes with zoonotic potential by nuclear ribosomal dna sequencesfn1fn1Note: Nucleotide sequence data reported in this paper are available in the embl, GenBankTM and DD
Publisher: Elsevier BV
Date: 12-1998
DOI: 10.1016/S0020-7519(98)00150-7
Abstract: Larvae of three species of anisakid nematode from fish, Anisakis simplex, Hysterothylacium aduncum and Contracaecum osculatum, were characterised genetically using a molecular approach. The nuclear ribosomal DNA region spanning the first internal transcribed spacer, the 5.8S gene and the second internal transcribed spacer was lified and sequenced. The lengths of the first and second internal transcribed spacer sequences of the three species ranged from 392 to 449 bp and 262 to 347 bp, respectively, whereas the 5.8S sequence was 157 bp. For the three species, the G+C contents for the three regions of ribosomal DNA ranged from 42.4 to 52.2%. While no intraspecific variation was detected in the second internal transcribed spacer or 5.8S sequence of any species examined, one polymorphic nucleotide position was detected in the first internal transcribed spacer sequence for A. simplex and H. aduncum. The extent of sequence differences in the first (approximately 34-45%) and second (approximately 50-53%) internal transcribed spacers among the species was greater than in the 5.8S gene (approximately 3-5%). Based on the sequence differences, PCR-based restriction fragment length polymorphism and single-strand conformation polymorphism methods were established for the unequivocal delineation of the three species. These methods should provide valuable tools for studying the life-cycle, transmission pattern(s) and population structure of each of the three anisakid nematodes examined herein, and for the diagnosis of anisakiasis in humans and animals.
Divergent Transcriptional Responses to Physiological and Xenobiotic Stress in Giardia duodenalis
Publisher: American Society for Microbiology
Date: 10-2016
DOI: 10.1128/AAC.00977-16
Abstract: Understanding how parasites respond to stress can help to identify essential biological processes. Giardia duodenalis is a parasitic protist that infects the human gastrointestinal tract and causes 200 to 300 million cases of diarrhea annually. Metronidazole, a major antigiardial drug, is thought to cause oxidative damage within the infective trophozoite form. However, treatment efficacy is suboptimal, due partly to metronidazole-resistant infections. To elucidate conserved and stress-specific responses, we calibrated sublethal metronidazole, hydrogen peroxide, and thermal stresses to exert approximately equal pressure on trophozoite growth and compared transcriptional responses after 24 h of exposure. We identified 252 genes that were differentially transcribed in response to all three stressors, including glycolytic and DNA repair enzymes, a mitogen-activated protein (MAP) kinase, high-cysteine membrane proteins, flavin adenine dinucleotide (FAD) synthetase, and histone modification enzymes. Transcriptional responses appeared to erge according to physiological or xenobiotic stress. Downregulation of the antioxidant system and α-giardins was observed only under metronidazole-induced stress, whereas upregulation of GARP-like transcription factors and their subordinate genes was observed in response to hydrogen peroxide and thermal stressors. Limited evidence was found in support of stress-specific response elements upstream of differentially transcribed genes however, antisense derepression and differential regulation of RNA interference machinery suggest multiple epigenetic mechanisms of transcriptional control.
An electrophoretic tool for the genetic characterisation and delineation of lungworms
Publisher: Elsevier BV
Date: 06-2004
Trichostrongylus vitrinus (Nematoda: Strongylida): Molecular characterization and transcriptional analysis of Tv-stp-1, a serine/threonine phosphatase gene
Publisher: Elsevier BV
Date: 09-2007
DOI: 10.1016/J.EXPPARA.2007.03.008
Abstract: A full-length cDNA (Tv-stp-1) encoding a serine/threonine protein phosphatase (Tv-STP-1) was isolated from Trichostrongylus vitrinus (order Strongylida), an economically important parasitic nematode of small ruminants. The uninterrupted open reading frame (ORF) of 951 nucleotides encoded a predicted protein of 316 amino acids (aa), containing the characteristic motif [LIVMN]-[KR]-G-N-H-E. Comparison with other sequences in non-redundant databases showed that Tv-STP-1 had significant identities/similarities to those from a range of metazoans and protists. Sequence similarity was most pronounced in the central region of the protein, in which the catalytic activity is inferred to be modulated by eight conserved residues (Asp 61, His 63, Asp 92, Asp 95, Asn 121, His 171, His 246 and Tyr 270), known to coordinate the binding of two metal ions (Mn2+ and Fe2+) in various organisms. Phylogenetic analyses of selected amino acid sequence data using the neighbor-joining and maximum parsimony methods revealed Tv-STP-1 to be most closely related to the glc seven-like phosphatases inferred for genes from the free-living nematode Caenorhabditis elegans and the parasitic nematode Oesophagostomum dentatum (order Strongylida). Comparison of the genomic organization of the full-length Tv-stp-1 gene with related molecules from other nematodes revealed substantial variation in the lengths and numbers of the exons and introns. The entire genes Tv-stp-1 (5041-5362 bp 10 exons and 9 introns) and Od-mpp-1 (10,271 bp 8 exons and 9 introns) from the parasitic nematodes T. vitrinus and O. dentatum were considerably longer than the C. elegans genes (1222-1603 bp 3-7 exons and 2-6 introns). Transcriptional analysis by reverse transcription polymerase chain reaction (RT-PCR) showed that Tv-stp-1 was transcribed in adult males of T. vitrinus, but not in the adult female or in any larval stages of this species. In spite of considerable variation at the genomic level, the findings of the present study suggest that there is relative conservation in features and function of the serine/threonine protein phosphatase characterized among T. vitrinus, O. dentatum and C. elegans, which should have implications for exploring molecular reproductive and developmental processes in strongylid nematodes of socio-economic importance.
RNA interference targeting cathepsin B of the carcinogenic liver fluke, Opisthorchis viverrini
Publisher: Elsevier BV
Date: 09-2011
Species-specific amplification by PCR of ribosomal DNA from some equine strongyles
Publisher: Cambridge University Press (CUP)
Date: 07-1999
DOI: 10.1017/S0031182099004497
Abstract: The first and second internal transcribed spacer sequences of 28 morphologically-defined species of horse strongyle were characterized, and specific oligonucleotide primers were designed for some species based on the nucleotide differences. Utilizing these primers, a PCR approach was developed for the specific lification of ribosomal DNA of Strongylus vulgaris , Cyathostomum catinatum , Cylicocyclus nassatus , Cylicostephanus longibursatus or Cylicostephanus goldi . The method allowed the species-specific lification of parasite DNA derived from faecal s les and/or copro-cultures, demonstrating the potential of the approach for the diagnosis of equine strongyloidosis. The establishment of this PCR assay also has implications for studying the biology and epidemiology of equine strongyles and anthelmintic resistance using faecal egg count reduction tests.
Investigating public health impacts of deer in a protected drinking water supply watershed
Publisher: IWA Publishing
Date: 07-2008
DOI: 10.2166/WST.2008.632
Abstract: The World Health Organisation's (WHO) Water Safety Plans highlight the need for preventative risk management when managing water contamination risks. As part of this approach, a management framework incorporating multiple barriers is necessary and there is a need to validate those barriers through scientific evidence. This paper reports on a study undertaken to validate the effectiveness, in terms of pathogen numbers, of having protected watersheds. The study aimed to determine if the deer population in a protected watershed carried Cryptosporidium and whether or not it was human infectious. Deer faecal s les were collected from the protected watersheds over a 12 month period and analysed using a new method, developed as part of this project, for genotyping Cryptosporidium. Early results showed the presence of Cryptosporidium, but following a refinement in the method no human infectious Cryptosporidium was detected. The results give some confidence that having protected watersheds is an effective barrier against pathogen contamination. They do not, however, imply that continued monitoring and management of the deer should cease. To maintain compliance with the Water Safety Plans, continual validation of barrier effectiveness is required.
Species markers for equine strongyles detected in intergenic rDNA by PCR-RFLP
Publisher: Elsevier BV
Date: 10-1996
Abstract: Five species of equine strongyle belonging to the subfamily Strongylinae (Strongylus edentatus, S. equinus, S. vulgaris, Oesophagodontus robustus and Triodontophorus serratus) and 11 species belonging to the subfamily Cyathostominae (Poteriostomum imparidentatum, P. ratzii, Cylicocyclus insignis, Cc. leptostomus, Cc. nassatus, Cylicostephanus calicatus, Cs. longibursatus, Cs. goldi, Cyathostomum catinatum, Cy. labiatum and Cy. pateratum) were characterized using a polymerase chain reaction-linked restriction fragment length polymorphism technique (PCR-RFLP). Internal transcribed spacer ribosomal DNA was lified from genomic DNA by polymerase chain reaction (PCR) using conserved primers, digested separately with six restriction endonucleases (AluI, BfaI, CfoI, Hae III, VSpI and XbaI) and the fragments separated by agarose gel electrophoresis. The PCR products of the three Strongylus species were approx. 90-100 bp smaller in size compared with those of the other 13 species. The PCR-RFLP analysis of the rDNA region spanning the first and second internal transcribed spacers plus the 5.85 rDNA gene (ITS+) produced characteristic patterns for each of the 16 species examined, and no variation in RFLP patterns was detected within the species Cy. catinatum, where multiple isolates were analysed. The study demonstrates that the internal transcribed spacer sequences provide genetic markers for the species identification of a range of equine strongyles. These markers will be of use for the identification of egg and larval stages, where morphological characters alone are unreliable. The results also indicate that the spacer sequences will be of use to study the systematics of equine strongyles.
First complete large subunit ribosomal RNA sequence and secondary structure for a parasitic nematode: phylogenetic and diagnostic implications
Publisher: Elsevier BV
Date: 02-2003
DOI: 10.1016/S0890-8508(02)00107-X
Abstract: The complete sequence and secondary structure of the large subunit of nuclear ribosomal RNA(LSUrRNA) were determined for the parasitic nematode Labiostrongylus bipapillosus (order Strongylida). Its LSU rRNA sequence was shorter (by 18 bp) than that of the free-living nematode, Caenorhabditis elegans (order Rhabditida), the only other species within the Nematoda for which a complete LSU rRNA sequence has been determined. Interspecific differences in sequence were greater in the 12 D domains compared with the core segments, with the secondary structure being maintained by partial or complete compensatory base pair changes. The magnitude of interspecific sequence difference in each D domain (except for D6 and D12) was similar, suggesting that several domains contain informative genetic markers for phylogenetic studies of the phylum Nematoda at different taxonomic levels. The LSU rRNA may also provide species-specific markers for the identification of some bursate nematodes of veterinary and medical importance.
The phylogenetic relationships of endemic Australasian trichostrongylin families (Nematoda: Strongylida) parasitic in marsupials and monotremes
Publisher: Springer Science and Business Media LLC
Date: 10-07-2015
DOI: 10.1007/S00436-015-4594-9
Abstract: The phylogenetic relationships of the endemic (or largely endemic) Australasian trichostrongylin nematode families Herpetostrongylidae, Mackerrastrongylidae and Nicollinidae as well as endemic trichostrongylin nematodes currently placed in the families Trichostrongylidae and Molineidae were examined using the complete large subunit (28S) ribosomal RNA gene. The Herpetostrongylinae proved to be monophyletic. However, representatives of the Nicollinidae nested with the Herpetostrongylinae. The Mackerrastrongylidae was also a monophyletic group and included Peramelistrongylus, currently classified within the Trichostrongylidae. The Globocephaloidinae, currently considered to be a subfamily of the Herpetostrongylidae, was excluded from the family in the current analysis. Ollulanus and Libyostrongylus, included for the first time in a molecular phylogenetic analysis, were placed within the Trichostrongylidae. This study provided strong support for the Herpetostrongylidae (including within it the Nicollinidae, but excluding the Globocephaloidinae) and the Mackerrastrongylidae as monophyletic assemblages. Additional studies are required to resolve the relationships of the remaining endemic Australasian trichostrongylin genera.
Variation in the sequence of a mitochondrial nadh dehydrogenase i gene fragment among six natural populations of Schistosoma japonicum from Chinafn1fn1Note: Nucleotide sequence data reported in this p
Publisher: Elsevier BV
Date: 12-1998
DOI: 10.1016/S0020-7519(98)00161-1
Abstract: The present study investigated the level of genetic variation among Schistosoma japonicum populations of different geographical origins from mainland China. Polymerase chain reaction-based methods were employed to determine the sequence for a subunit of the mitochondrial NADH dehydrogenase I gene for populations from Zhejiang, Anhui, Jiangxi, Hunan, Hubei and Sichuan. No variation was detectable in the NADH dehydrogenase I sequence within populations from Zhejiang and Hubei, whereas sequence variation of 0.2% was detected within populations from Anhui, Jiangxi, Hunan and Sichuan. Pairwise comparison of the sequences representing the six different populations revealed genetic differences ranging from 0 to 0.6%.
New Editor-in-Chief of the International Journal for Parasitology
Publisher: Elsevier BV
Date: 04-2015
Enterocytozoon bieneusi genotypes in people with gastrointestinal disorders in Queensland and Western Australia.
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.MEEGID.2018.08.006
Abstract: Enterocytozoon bieneusi is the commonest pathogenic microsporidian found in humans and animals in many countries, but there is scant information on this pathogen in Australia. Here, we conducted the first molecular epidemiological investigation of E. bieneusi in humans with gastrointestinal disorders in Queensland and Western Australia. Genomic DNAs derived from 605 in idual faecal s les from children (n = 279) and adults (n = 326) were extracted, and then subjected to nested PCR-based sequencing of the internal transcribed spacer (ITS) of nuclear ribosomal DNA to detect and characterise E. bieneusi. Enterocytozoon bieneusi was detected in eight of 605 human faecal s les (1.3%), including five children (≤3 years of age) and one adult (58 years) in Queensland, and two children (≤3 years) in Western Australia. Analysis of ITS sequence data revealed two known zoonotic (ALP1 and Ind4) and three novel (Hum_q1-3) genotypes of E. bieneusi. Genotype ALP1 identified here in humans has been found previously in farmed alpacas in Australia. Phylogenetic analysis showed that genotypes ALP1, Hum_q1-2 and Ind4 belonged to E. bieneusi Group 1 (with zoonotic potential), whereas genotype Hum_q3 clustered within E. bieneusi Group 10, suggesting that some genotypes within Group 10 might have zoonotic potential. Further investigations of humans, alpacas, marsupials and other animals in Australia will be significant to understand the epidemiology of E. bieneusi in Australia, to identify possible reservoirs of human infection, and to assist in the prevention and control of human microsporidiosis.
Advanced in silico analysis of expressed sequence tag (EST) data for parasitic nematodes of major socio-economic importance - Fundamental insights toward biotechnological outcomes
Publisher: Elsevier BV
Date: 07-2009
DOI: 10.1016/J.BIOTECHADV.2009.03.005
Abstract: Parasitic nematodes infect humans, other animals and plants, and impose a significant public health and economic burden worldwide due to the diseases that they cause. A better understanding of parasite genomes, host-parasite relationships and the molecular biology of parasites themselves will enable the rational development of diagnostic tests and/or safe anti-parasitic compounds, following the functional annotation of parasite genomic sequences. With only a few completely sequenced nematode genomes, expressed sequence tag (EST) datasets provide a low-cost alternative ("poor man's genome") to whole genome sequences and a glimpse of the transcriptome of an organism. EST data require a number of computational methods for their pre-processing, clustering, assembly and annotation to yield biologically relevant information. In this article, we review the steps involved in EST data analysis, the development of new semi-automated bioinformatic pipelines and their application to parasitic nematodes of major socio-economic significance, focused on identifying molecules involved in key biological processes or pathways that might serve as targets for new drugs or vaccines.
Use of RAPD for the detection of genetic variation in the human blood fluke,Schistosoma japonicum, from mainland China
Publisher: Elsevier BV
Date: 10-1996
Abstract: A random lified polymorphic DNA (RAPD) technique using 16 decamer oligonucleotide primers was employed to characterize isolates of Schistosoma japonicum from seven geographical locations (Sj1: Zhejiang Sj2: Anhui Sj3: Jiangxi Sj4: Hunan Sj5: Hubei Sj6: Sichuan Sj7: Yunnan) of the People's Republic of China. Distinct differences between some isolates were reproducibly detected in RAPD patterns produced using five of the primers. The analyses showed that both Sj6 and Sj7 were quite distinct genetically from Sj1-Sj5 based on the presence/absence of particular bands (A10-200 bp, A9-220 bp, B17-520 bp, P205-680 bp and P235-930 bp). These findings are in line with previous reports on the biological, biochemical, immunological and chemotherapeutic differences of S. japonicum from Sichuan and Yunnan compared with other geographical regions. The present study showed, based on RAPD profiles, that genetic differences exist within S. japonicum from mainland China. This finding may have important implications for studying the population biology, epidemiology and clinical forms of the disease in China, as well as for developing vaccines and diagnostic test systems.
Molecular epidemiological investigation of Ascaris genotypes in China based on single-strand conformation polymorphism analysis of ribosomal DNA
Publisher: Wiley
Date: 07-2003
Abstract: Using a single-strand conformation polymorphism-based approach, we investigated nucleotide variation in part of the first internal transcribed spacer (pITS-1) of nuclear ribosomal DNA within and among a large number of Ascaris in iduals from humans and pigs from six endemic regions in China, and examined the frequency of the different genotypes of Ascaris in relation to host species and geographical origin. Five different SSCP genotypes (G1-G5) were recorded for human Ascaris (n = 486), of which three (genotypes G1-G3) were detected for pig Ascaris (n = 329). Of the five Ascaris genotypes detected, genotype G1 predominantly infected humans (approximately 63-74%) whereas genotype G3 infected mainly pigs (approximately 79-86%), indicating that each of these genotypes has a particular host affiliation. In contrast, the frequencies of the other three genotypes was substantially lower for each of the two host species. The findings also suggested that the rate of cross infection of Ascaris between humans and pigs is relatively low and that gene flow between the predominant genotypes is limited, consistent with previous proposals for endemic regions in other countries. While the nature and extent of nucleotide variation in the pITS-1 (and the proposal of host affiliated Ascaris populations) may relate to "introgression" or "lineage sorting and retention of ancentral polymorphism", other explanations are possible. Evidence of multiple pITS-1 sequence types in some Ascaris in iduals representing particular genotypes (e.g., G2 and G5) may suggest hybridization between human- and pig-affiliated Ascaris. This aspect and the species status of Ascaris (from each host species) warrant future experimental testing, employing the pig/Ascaris model and the present electrophoretic approach.*
Definition of genetic markers in nuclear ribosomal DNA for a neglected parasite of primates, Ternidens deminutus (Nematoda: Strongylida) – diagnostic and epidemiological implications
Publisher: Cambridge University Press (CUP)
Date: 23-05-2005
Haemonchus contortus: Prokaryotic expression and enzyme activity of recombinant HcSTK, a serine/threonine protein kinase
Publisher: Elsevier BV
Date: 08-2006
DOI: 10.1016/J.EXPPARA.2006.01.004
Abstract: Members of the PAR-1/MARK serine/threonine protein kinase (STK) subfamily are important regulators of the cytoskeleton, and their characterization can provide insights into a number of critical processes relating to the development and survival of an organism. We previously investigated the mRNA expression for and organization of a gene (hcstk) representing HcSTK, an STK from the parasitic nematode Haemonchus contortus. In the present study, a recombinant form of HcSTK was expressed and characterized. Affinity-purified anti-HcSTK antibodies reacted with native HcSTK in protein homogenates extracted from third-stage larvae (L3) of H. contortus and were also used to immunolocalize the protein around the nuclei of ovarian and intestinal tissues of adult H. contortus. The enzyme activity of the recombinant HcSTK protein was also demonstrated. The findings show that recombinant HcSTK is a functional protein kinase, with activity directed to KXGS motifs, consistent with other members of the PAR-1/MARK STK subfamily.
Semiquantitative Multiplexed Tandem PCR for Detection and Differentiation of Four Theileria orientalis Genotypes in Cattle
Publisher: American Society for Microbiology
Date: 2015
DOI: 10.1128/JCM.02536-14
Abstract: Oriental theileriosis is an emerging, tick-borne disease of bovines in the Asia-Pacific region and is caused by one or more genotypes of the Theileria orientalis complex. This study aimed to establish and validate a multiplexed tandem PCR (MT-PCR) assay using three distinct markers (major piroplasm surface protein, 23-kDa piroplasm membrane protein, and the first internal transcribed spacer of nuclear DNA), for the simultaneous detection and semiquantification of four genotypes (Buffeli, Chitose, Ikeda, and type 5) of the T. orientalis complex. Analytical specificity, analytical sensitivity, and repeatability of the established MT-PCR assay were assessed in a series of experiments. Subsequently, the assay was evaluated using 200 genomic DNA s les collected from cattle from farms on which oriental theileriosis outbreaks had occurred, and 110 s les from a region where no outbreaks had been reported. The results showed the MT-PCR assay specifically and reproducibly detected the expected genotypes (i.e., genotypes Buffeli, Chitose, Ikeda, and type 5) of the T. orientalis complex, reliably differentiated them, and was able to detect as little as 1 fg of genomic DNA from each genotype. The diagnostic specificity and sensitivity of the MT-PCR were estimated at 94.0% and 98.8%, respectively. The MT-PCR assay established here is a practical and effective diagnostic tool for the four main genotypes of T. orientalis complex in Australia and should assist studies of the epidemiology and pathophysiology of oriental theileriosis in the Asia-Pacific region.
Speciation in the genus Cloacina (Nematoda: Strongylida): Species flocks and intra-host speciation
Publisher: Cambridge University Press (CUP)
Date: 12-07-2017
DOI: 10.1017/S0031182017001238
Abstract: Sequences of the first and second internal transcribed spacers (ITS1 + ITS2) of nuclear ribosomal DNA were employed to determine whether the congeneric assemblages of species of the strongyloid nematode genus Cloacina , found in the forestomachs of in idual species of kangaroos and wallabies (Marsupialia: Macropodidae), considered to represent species flocks, were monophyletic. Nematode assemblages examined in the black-striped wallaby, Macropus ( Notamacropus ) dorsalis , the wallaroos, Macropus ( Osphranter ) antilopinus / robustus , rock wallabies, Petrogale spp., the quokka, Setonix brachyurus, and the sw wallaby, Wallabia bicolor, were not monophyletic and appeared to have arisen by host colonization. However, a number of instances of within-host speciation were detected, suggesting that a variety of methods of speciation have contributed to the evolution of the complex assemblages of species present in this genus.
A communal catalogue reveals Earth’s multiscale microbial diversity
Publisher: Springer Science and Business Media LLC
Date: 11-2017
DOI: 10.1038/NATURE24621
Abstract: Our growing awareness of the microbial world’s importance and ersity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community s les collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of ersity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial ersity.
Transcriptomics indicates active and passive metronidazole resistance mechanisms in three seminal Giardia lines
Publisher: Frontiers Media SA
Date: 17-03-2017
Toward integrative ‘omics of the barber's pole worm and related parasitic nematodes
Publisher: Elsevier BV
Date: 11-2020
Multiplex PCR for the detection and quantification of zoonotic taxa of Giardia, Cryptosporidium and Toxoplasma in wastewater and mussels
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.MCP.2015.01.001
Abstract: Giardia duodenalis, Cryptosporidium parvum and Toxoplasma gondii are important parasitic protists linked to water- and food-borne diseases. The accurate detection of these pathogens is central to the diagnosis, tracking, monitoring and surveillance of these protists in humans, animals and the environment. In this study, we established a multiplex real-time PCR (qPCR), coupled to high resolution melting (HRM) analysis, for the specific detection and quantification of each G. duodenalis (assemblage A), C. parvum and T. gondii (Type I). Once optimised, this assay was applied to the testing of s les (n = 232) of treated wastewater and mussels (Mytilus galloprovincialis). Of 119 water s les, 28.6% were test-positive for G. duodenalis, C. parvum and/or both pathogens of 113 mussel s les, 66.6% were test-positive for G. duodenalis, C. parvum and/or both pathogens, and 13.2% were test-positive for only T. gondii. The specificity of all licons produced was verified by direct sequencing. The oo/cysts numbers (per 5 μl of DNA s le) ranged from 10 to 64. The present multiplex assay achieved an efficiency of 100% and a R(2) value of >0.99. Current evidence indicates that this assay provides a promising tool for the simultaneous detection and quantitation of three key protist taxa.
Identification and genetic characterization of A nisakis larvae from marine fishes in the S outh C hina S ea using an electrophoretic‐guided approach
Publisher: Wiley
Date: 03-2013
Abstract: From 35 species of marine fishes (n = 327) from the South China Sea, 237 nematode larvae were collected and identified morphologically as Anisakis. Genomic DNA was isolated from each larva and subjected to PCR-based RFLP and targeted sequencing of a nuclear ribosomal DNA region between the 3'-end of the small subunit and 5'-end of the large subunit of the rRNA genes (= internal transcribed spacers, ITS+). Four different RFLP profile combinations (sets) were detected for all restriction endonucleases (HinfI, HhaI, and TaqI), of which three were characteristic of Anisakis typica, A. pegreffii, and A. physeteris, respectively. One profile set (for s le CA-2012) was linked to an ITS+ sequence that was identical to a previously published sequence of Anisakis sp. (s le HC-2005 originating from the African shelf) and another sequence (PH-2010 Madeira, Portugal). Phylogenetic analysis was carried out using the ITS+ sequence data from this study and reference sequences from the GenBank database. Neighbor joining and maximum parsimony trees displayed three clades. Clades I and II included nine described species of Anisakis, including all type I and type II larvae clade III represented some undescribed species of Anisakis. Morphological comparison showed that Anisakis sp. CA-2012 was distinct from type I and type II larvae based on its tail shape and ratio of tail length to body length. The phylogenetic analysis and morphological characters suggest that Anisakis sp. CA-2012 represents a new record, now called Anisakis type III larvae.
Probing of a human proteome microarray with a recombinant pathogen protein reveals a novel mechanism by which hookworms suppress B-cell receptor signaling
Publisher: Oxford University Press (OUP)
Date: 19-08-2015
Abstract: Na-ASP-2 is an efficacious hookworm vaccine antigen. However, despite elucidation of its crystal structure and studies addressing its immunobiology, the function of Na-ASP-2 has remained elusive. We probed a 9000-protein human proteome microarray with Na-ASP-2 and showed binding to CD79A, a component of the B-cell antigen receptor complex. Na-ASP-2 bound to human B lymphocytes ex vivo and downregulated the transcription of approximately 1000 B-cell messenger RNAs (mRNAs), while only approximately 100 mRNAs were upregulated, compared with control-treated cells. The expression of a range of molecules was affected by Na-ASP-2, including factors involved in leukocyte transendothelial migration pathways and the B-cell signaling receptor pathway. Of note was the downregulated transcription of lyn and pi3k, molecules that are known to interact with CD79A and control B-cell receptor signaling processes. Together, these results highlight a previously unknown interaction between a hookworm-secreted protein and B cells, which has implications for helminth-driven immunomodulation and vaccine development. Further, the novel use of human protein microarrays to identify host-pathogen interactions, coupled with ex vivo binding studies and subsequent analyses of global gene expression in human host cells, demonstrates a new pipeline by which to explore the molecular basis of infectious diseases.
Characterization of a Caenorhabditis elegans glc seven-like phosphatase (gsp) orthologue from Haemonchus contortus (Nematoda)
Publisher: Elsevier BV
Date: 08-2010
DOI: 10.1016/J.MCP.2010.02.001
Abstract: A full-length complementary DNA (cDNA designated Hc-stp-1) encoding a serine/threonine phosphatase (Hc-STP-1) was isolated from Haemonchus contortus, a strongylid nematode parasite of small ruminants. Hc-stp-1 was shown to be transcribed in males of both adults and fourth-stage larvae, but not in females, early larval stages or eggs. The full-length gene (2854 bp) contained ten exons and nine introns, and encoded a cDNA of 951 bp. Comparisons of the conceptually translated protein (316 amino acids, estimated at approximately 35 kDa) with serine/threonine phosphatases (STPs) from other organisms revealed the presence of the conserved motif LRGNHE. Structural analysis, by comparative modelling, confirmed strict conservation of residues and features involved in catalytic activity, and variation in the ligand-binding interface. Phylogenetic analysis of amino acid sequence data revealed that Hc-STP-1 clustered with STPs from other nematodes (including Caenorhabditis elegans, Trichostrongylus vitrinus, Oesophagostomum dentatum, Ascaris suum and Brugia malayi) to the exclusion of STPs from other organisms. The protein was inferred to be most closely related to the PP1 class of STPs of C. elegans, within a group containing STPs encoded, amongst others, by the genes gsp-3 and gsp-4 in this free-living nematode. The functions of proteins GSP-3 and GSP-4 are known to be central to spermatogenesis and other male-specific processes in C. elegans. The findings from the present and previous studies support the proposal that Hc-stp-1 and its product play a significant role in reproductive and/or developmental processes in maturing or adult male H. contortus.
Genetic divergence between island and continental populations of the parasitic nematode Labiosimplex australis in Australia.
Publisher: Springer Science and Business Media LLC
Date: 16-09-2008
DOI: 10.1007/S00436-008-1178-Y
Abstract: Sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal (r) DNA were characterised for Labiosimplex australis, a parasitic nematode of macropodid marsupials from continental Australia and from island populations which have been isolated from mainland Australia for relatively short periods of time (<40,000 years). The results showed that the geographically isolated populations of L. australis on Kangaroo Island and Tasmania were genetically different from each other and from populations on the mainland. There were two unequivocal nucleotide differences sites within the ITS-1 rDNA sequence between the two island populations however, the ITS-1 sequences of in iduals from mainland populations contained one or both of these nucleotides. In contrast, L. australis from each island population had unique nucleotides in ITS-2 sequence that were not detected in any in idual from the mainland. Although these results are consistent with the hypothesis that L. australis represents a single species, the genetic ergence in the ITS-2 sequences amongst in iduals from different isolated populations suggests that the island populations of L. australis may be in the initial stages of allopatric speciation.
The mitochondrial genomes of the human hookworms, Ancylostoma duodenale and Necator americanus (Nematoda: Secernentea)
Publisher: Elsevier BV
Date: 02-2002
DOI: 10.1016/S0020-7519(01)00316-2
Abstract: The complete mitochondrial genome sequences were determined for two species of human hookworms, Ancylostoma duodenale (13,721 bp) and Necator americanus (13,604 bp). The circular hookworm genomes are amongst the smallest reported to date for any metazoan organism. Their relatively small size relates mainly to a reduced length in the AT-rich region. Both hookworm genomes encode 12 protein, two ribosomal RNA and 22 transfer RNA genes, but lack the ATP synthetase subunit 8 gene, which is consistent with three other species of Secernentea studied to date. All genes are transcribed in the same direction and have a nucleotide composition high in A and T, but low in G and C. The AT bias had a significant effect on both the codon usage pattern and amino acid composition of proteins. For both hookworm species, genes were arranged in the same order as for Caenorhabditis elegans, except for the presence of a non-coding region between genes nad3 and nad5. In A. duodenale, this non-coding region is predicted to form a stem-and-loop structure which is not present in N. americanus. The mitochondrial genome structure for both hookworms differs from Ascaris suum only in the location of the AT-rich region, whereas there are substantial differences when compared with Onchocerca volvulus, including four gene or gene-block translocations and the positions of some transfer RNA genes and the AT-rich region. Based on genome organisation and amino acid sequence identity, A. duodenale and N. americanus were more closely related to C. elegans than to A. suum or O. volvulus (all secernentean nematodes), consistent with a previous phylogenetic study using ribosomal DNA sequence data. Determination of the complete mitochondrial genome sequences for two human hookworms (the first members of the order Strongylida ever sequenced) provides a foundation for studying the systematics, population genetics and ecology of these and other nematodes of socio-economic importance.
An outbreak of oriental theileriosis in dairy cattle imported to Vietnam from Australia
Publisher: Cambridge University Press (CUP)
Date: 12-12-2016
DOI: 10.1017/S0031182016002328
Abstract: This study reports an outbreak of oriental theileriosis in dairy cattle imported to Vietnam from Australia. Following clinical and pathological diagnoses, a total of 112 cattle blood s les were ided into three groups and tested using multiplexed tandem PCR. Group 1 were from aborted heifers in Vietnam group 2 were from cattle before shipment from group 1 cattle and group 3 were from the same batch of cattle but transported to Taiwan. Theileria orientalis DNA was detected in 72·3% cattle. The prevalences of T. orientalis in groups 1, 2 and 3 were 77·6, 86·9 and 57·5%, respectively, and the difference in prevalence was significant between groups 1 and 3 ( P 0·0001). The infection intensities of genotypes chitose and ikeda of T. orientalis were higher in groups 1 (57 721 and 33 709, respectively) and 3 (5897 and 61 766, respectively) than those in group 2 (2071 and 6331, respectively). Phylogenetic analyses of the major piroplasm surface protein sequences revealed that genotypes chitose and ikeda determined herein were closely related to those previously reported from Australia. This first report of an outbreak of oriental theileriosis in imported cattle emphasizes improved measures for the export and import of cattle infected with T. orientalis .
Hammondia isolated from dogs and foxes are genetically distinct
Publisher: Cambridge University Press (CUP)
Date: 27-09-2006
Phylogenetic analysis of the Australasian paralysis ticks and their relatives (Ixodidae: Ixodes: Sternalixodes)
Publisher: Springer Science and Business Media LLC
Date: 02-03-2017
Dauer signalling pathway model for Haemonchus contortus.
Publisher: Springer Science and Business Media LLC
Date: 29-04-2019
DNA technological progress toward advanced diagnostic tools to support human hookworm control
Publisher: Elsevier BV
Date: 2008
DOI: 10.1016/J.BIOTECHADV.2007.09.003
Abstract: Blood-feeding hookworms are parasitic nematodes of major human health importance. Currently, it is estimated that 740 million people are infected worldwide, and more than 80 million of them are severely affected clinically by hookworm disease. In spite of the health problems caused and the advances toward the development of vaccines against some hookworms, limited attention has been paid to the need for improved, practical methods of diagnosis. Accurate diagnosis and genetic characterization of hookworms is central to their effective control. While traditional diagnostic methods have considerable limitations, there has been some progress toward the development of molecular-diagnostic tools. The present article provides a brief background on hookworm disease of humans, reviews the main methods that have been used for diagnosis and describes progress in establishing polymerase chain reaction (PCR)-based methods for the specific diagnosis of hookworm infection and the genetic characterisation of the causative agents. This progress provides a foundation for the rapid development of practical, highly sensitive and specific diagnostic and analytical tools to be used in improved hookworm prevention and control programmes.
Genomic and genetic research on bursate nematodes: significance, implications and prospects
Publisher: Elsevier BV
Date: 04-2000
DOI: 10.1016/S0020-7519(00)00021-7
Abstract: Molecular genetic research on parasitic nematodes (order Strongylida) is of major significance for many fundamental and applied areas of medical and veterinary parasitology. The advent of gene technology has led to some progress for this group of nematodes, particularly in studying parasite systematics, drug resistance and population genetics, and in the development of diagnostic assays and the characterisation of potential vaccine and drug targets. This paper gives an account of the molecular biology and genetics of strongylid nematodes, mainly of veterinary socio-economic importance, indicates the implications of such research and gives a perspective on genome research for this important parasite group, in light of recent technological advances and knowledge of the genomes of other metazoan organisms.
Multilocus mutation scanning for the analysis of genetic variation withinMalassezia (Basidiomycota: Malasseziales)
Publisher: Wiley
Date: 04-2007
Abstract: Members of the genus Malassezia are budding yeasts, characterized by a thick cell wall. Recently, these yeasts have received attention as emerging pathogens. They are common commensals on the skin of animals and can become pathogenic under the influence of various predisposing factors. Central to studying their taxonomy, systematics, and ecology and to diagnosis is the accurate identification of species or operational taxonomic units. To overcome the limitations of current phenotypic and biochemical methods of identification, a PCR-coupled SSCP approach, utilizing sequence variation (0.4-33.5%) in short regions (approximately 250-270 bp) of the first internal transcribed spacer (ITS-1) of nuclear ribosomal DNA and the chitin synthase-2 gene (chs-2), was assessed for the identification and differentiation of different species/genotypes of Malassezia, characterized previously by DNA sequencing. Genomic DNA s les (n = 30) from Malassezia isolates cultured from canine skin scrapings were assessed by SSCP analysis of the two different genetic loci, and unequivocal delineation between genotypes and species was achieved. This SSCP approach is considered to provide a practical tool for the rapid and reliable genetic characterization of Malassezia genotypes/species from dogs and for investigating their population genetics and ecology. It will also provide a powerful tool for studies of Malassezia isolates from other animal species.
The Haemonchus contortus kinome - A resource for fundamental molecular investigations and drug discovery
Publisher: Springer Science and Business Media LLC
Date: 12-2015
Genetic variation within species of the nematode genus Cloacina (Strongyloidea: Cloacininae) parasitic in the stomachs of rock wallabies, Petrogale spp. (Marsupialia:Macropodidae) in Queensland
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/ZO08068
Abstract: Four morphospecies of Cloacina, parasitic nematodes in the stomachs of rock wallabies (Petrogale spp.) from Queensland, were compared genetically using sequence data of the two internal transcribed spacers of nuclear ribosomal DNA (rDNA). The results suggest that two geographically isolated populations of C. ernabella from P. purpureicollis were genetically distinct. Based on the autapomorphic species concept, these two C. ernabella populations represented different species. For the three other nematode morphospecies, there were genetic differences among in iduals of a morphospecies present in different species of host. The results suggest that each may represent a complex of sibling species, with a different species present in each species of rock wallaby examined for that morphospecies. In the C. caenis and C. pearsoni complexes, the lineage present in P. purpureicollis from western Queensland represents a sister taxon to those in the P. pencillata complex from the east coast. In the C. robertsi complex, the taxon parasitic in P. persephone represents the sister taxon to those in the P. pencillata complex and in P. purpureicollis. C. robertsi was found for the first time in P. purpureicollis from Winton in central Queensland, suggesting contact in the recent past between populations of P. purpureicollis and a member of the P. penicillata complex.
Differences in transcription between free-living and CO2-activated third-stage larvae of Haemonchus contortus
Publisher: Springer Science and Business Media LLC
Date: 27-04-2010
Abstract: The disease caused by Haemonchus contortus , a blood-feeding nematode of small ruminants, is of major economic importance worldwide. The infective third-stage larva (L3) of this gastric nematode is enclosed in a cuticle (sheath) and, once ingested with herbage by the host, undergoes an exsheathment process that marks the transition from the free-living (L3) to the parasitic (xL3) stage. This study explored changes in gene transcription associated with this transition and predicted, based on comparative analysis, functional roles for key transcripts in the metabolic pathways linked to larval development. Totals of 101,305 (L3) and 105,553 (xL3) expressed sequence tags (ESTs) were determined using 454 sequencing technology, and then assembled and annotated the most abundant transcripts encoded transthyretin-like, calcium-binding EF-hand, NAD(P)-binding and nucleotide-binding proteins as well as homologues of Ancylostoma -secreted proteins (ASPs). Using an in silico -subtractive analysis, 560 and 685 sequences were shown to be uniquely represented in the L3 and xL3 stages, respectively the transcripts encoded ribosomal proteins, collagens and elongation factors (in L3), and mainly peptidases and other enzymes of amino acid catabolism (in xL3). Caenorhabditis elegans orthologues of transcripts that were uniquely transcribed in each L3 and xL3 were predicted to interact with a total of 535 other genes, all of which were involved in embryonic development. The present study indicated that some key transcriptional alterations taking place during the transition from the L3 to the xL3 stage of H. contortus involve genes predicted to be linked to the development of neuronal tissue (L3 and xL3), formation of the cuticle (L3) and digestion of host haemoglobin (xL3). Future efforts using next-generation sequencing and bioinformatic technologies should provide the efficiency and depth of coverage required for the determination of the complete transcriptomes of different developmental stages and/or tissues of H. contortus as well as the genome of this important parasitic nematode. Such advances should lead to a significantly improved understanding of the molecular biology of H. contortus and, from an applied perspective, to novel methods of intervention.
Strongyloid nematodes in the caeca of donkeys in Henan Province, China
Publisher: Walter de Gruyter GmbH
Date: 2009
DOI: 10.2478/S11686-009-0037-Z
Abstract: Thirty-four donkeys from Henan Province, China, were examined at necropsy for strongyloid nematodes in the caecum (February 2006 to January 2007). Twenty-two species, including 18 Cyathostominae (small strongyles) and 4 Strongylinae (large strongyles), were identified. The five most prevalent Cyathostominae were Cylicocyclus nassatus (73.5%), Coronocyclus labratus (70.6%), Coronocyclus labiatus (67.6%), Cyathostomum tetracanthum (61.8%) and Coronocyclus coronatus (52.9%), accounting for 70.2% of all species identified C. labratus (124.2 ± 256.4), Cyathostomum tetracanthum (96.4 ± 210.5) and Cylicocyclus nassatus (80.9 ± 117.1) had the greatest mean abundance, whereas Strongylus vulgaris was the most prevalent (88.2%) of the Strongylinae and had the highest mean abundance (34.9 ± 37.8). The numbers of species per donkey ranged from 1 to 15 (with a median of 7.1). Only a small percentage (5.9%) of donkeys were infected by a single species, whereas the other donkeys had infections with multiple species.
Detection of Cyclospora in captive chimpanzees and macaques by a quantitative PCR-based mutation scanning approach.
Publisher: Springer Science and Business Media LLC
Date: 15-05-2015
Phylogenetic relationships of three tribes of cloacinine nematodes (Strongylida: Chabertiidae) from macropodid marsupials.
Publisher: Cambridge University Press (CUP)
Date: 19-04-2018
DOI: 10.1017/S0022149X1800038X
Abstract: The phylogenetic relationships of 42 species of cloacinine nematodes belonging to three tribes (Coronostrongylinea, Macropostrongylinea and Zoniolaiminea) were examined based on sequence data of the first and second internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA. All nematodes examined are parasites of Australian macropodid marsupials. None of the three nematode tribes was monophyletic. Paraphyly was also encountered in three genera: Papillostrongylus , Monilonema and Wallabinema . Species within the genus Thallostonema were limited to a single host genus (i.e. Thylogale ), whereas species within the five principal genera ( Coronostrongylus , Macropostrongylus , Popovastrongylus , Wallabinema and Zoniolaimus ) were found to occur in multiple host genera. Potential modes of evolution among these nematodes are discussed.
A practical and cost-effective mutation scanning-based approach for investigating genetic variation in Cryptosporidium
Publisher: Wiley
Date: 11-2007
Abstract: In the present study, we used a mutation scanning-targeted sequencing approach to assess variation in part (pgp60) of the 60 kDa glycoprotein (gp60) gene among Cryptosporidium s les from humans in Victoria, Australia. Two nuclear ribosomal loci (the small subunit rRNA gene and the second internal transcribed spacer) were used to identify the s les as Cryptosporidium hominis (n = 74), Cryptosporidium parvum (n = 23) or Cryptosporidium meleagridis (n = 1). In total, nine distinct pgp60 sequences were identified (three C. hominis, five C. parvum and one C. meleagridis). Phylogenetic analyses of the pgp60 sequence data, employing well-defined reference sequences for comparison, allowed the genotypic and subgenotypic classification of s les. The C. hominis s les were classified as Ib A10G2R2, Id A15G1R2, and a new genotype, designated Ib2, was identified subgenotypically as A18G1R4. The C. parvum s les were classified as IIa A18G3R1, IIa A20G3R1, IIa A22G3R1, IIa A23G3R1 and IIc A5G3R2. These findings suggested that the C. hominis metapopulation is largely homogeneous, consisting of a single dominant genotype, Ib A10G2R2, whereas the C. parvum metapopulation is considerably more heterogeneous, with no single dominant genotype. The greater level of genetic heterogeneity found among the C. parvum s les, despite the smaller s le size, may relate to the zoonotic infection pattern of this species, which would be reflective of a greater number of possible infection sources. The present mutation scanning approach, coupled with targeted sequencing of genetically distinct representatives, is a practical, cost-effective tool for large-scale population genetic and epidemiological studies of Cryptosporidium and other eukaryotic organisms.
Analysis of nucleotide variation within the triose-phosphate isomerase gene of Giardia duodenalis from sheep and its zoonotic implications
Publisher: Wiley
Date: 2010
Abstract: This study explored the genetic composition of Giardia in fecal s les from 284 in idual lambs on pasture-based sheep farms in three regions of Victoria, Australia. An approach, combining targeted sequencing, phylogenetic analysis and PCR-coupled restriction endonuclease fingerprinting, was used to identify and genetically categorize Giardia present in 43 (15.1%) of the 284 s les and to infer their zoonotic potential. The specific identity and genetic classification were based on the phylogenetic analysis of sequence data for a portion of the triose-phosphate isomerase gene. Fourteen different sequence variants (including seven sequences that contained between one and five polymorphic sites) representing two distinct assemblages of Giardia (recognized in the current literature) were defined, of which 13 were new records. One dominant sequence type (with accession no. GQ444447, representing a genotype within assemblage A) has been detected previously in humans and is thus considered to be of zoonotic potential. (Nucleotide sequences reported in this article are available in the GenBank database under accession nos. GQ444447-GQ444451 and GQ444454-GQ444462).
Gender-enriched transcripts in Haemonchus contortus - predicted functions and genetic interactions based on comparative analyses with Caenorhabditis elegans
Publisher: Elsevier BV
Date: 2008
DOI: 10.1016/J.IJPARA.2007.07.001
Abstract: In the present study, a bioinformatic-microarray approach was employed for the analysis of selected expressed sequence tags (ESTs) from Haemonchus contortus, a key parasitic nematode of small ruminants. Following a bioinformatic analysis of EST data using a semiautomated pipeline, 1885 representative ESTs (rESTs) were selected, to which oligonucleotides (three per EST) were designed and spotted on to a microarray. This microarray was hybridized with cyanine-dye labelled cRNA probes synthesized from RNA from female or male adults of H. contortus. Differential hybridisation was displayed for 301 of the 1885 rESTs ( approximately 16%). Of these, 165 (55%) had significantly greater signal intensities for female cRNA and 136 (45%) for male cRNA. Of these, 113 with increased signals in female or male H. contortus had homologues in Caenorhabditis elegans, predicted to function in metabolism, information storage and processing, cellular processes and signalling, and embryonic and/or larval development. Of the rESTs with no known homologues in C. elegans, 24 ( approximately 40%) had homologues in other nematodes, four had homologues in various other organisms and 30 (52%) had no homology to any sequence in current gene databases. A genetic interaction network was predicted for the C. elegans orthologues of the gender-enriched H. contortus genes, and a focused analysis of a subset revealed a tight network of molecules involved in amino acid, carbohydrate or lipid transport and metabolism, energy production and conversion, translation, ribosomal structure and biogenesis and, importantly, those associated with meiosis and/or mitosis in the germline during oogenesis or spermatogenesis. This study provides a foundation for the molecular, biochemical and functional exploration of selected molecules with differential transcription profiles in H. contortus, for further microarray analyses of transcription in different developmental stages of H. contortus, and for an extended functional analysis once the full genome sequence of this nematode is known.
First insight into CD59-like molecules of adult Fasciola hepatica
Publisher: Elsevier BV
Date: 09-2014
DOI: 10.1016/J.EXPPARA.2014.06.012
Abstract: The present study focussed on investigating CD59-like molecules of Fasciola hepatica. A cDNA encoding a CD59-like protein (termed FhCD59-1) identified previously in the membrane fraction of the F. hepatica tegument was isolated. This homologue was shown to encode a predicted open reading frame (ORF) of 122 amino acids (aa) orthologous to human CD59 with a 25 aa signal peptide, a mature protein containing 10 cysteines and a conserved CD59/Ly-6 family motif "CCXXXXCN". An analysis of cDNAs from two different adult specimens of F. hepatica revealed seven variable types of FhCD59-1 sequences, designated FhCD59-1.1 to FhCD59-1.7, which had 94.3-99.7% amino acid sequence identity upon pairwise comparison. Molecular modeling of FhCD59-1.1 with human CD59 confirmed the presence of the three-finger protein domain found in the CD59 family and predicted three disulphide bonds in the F. hepatica sequence. The interrogation of F. hepatica databases identified two additional sequences, designated FhCD59-2 and FhCD59-3, which had only 23.4-29.5% amino acid identity to FhCD59-1.1. Orthologues of the inferred CD59 protein sequences of F. hepatica were also identified in other flatworms, including Fasciola gigantica, Fascioloides magna, Schistosoma haematobium, Schistosoma japonicum, Schistosoma mansoni, Clonorchis sinensis, Opisthorchis viverrini, Taenia solium, Echinococcus granulosus and the free living Schmidtea mediterannea. The results revealed a considerable degree of sequence complexity in the CD59-like sequence families in F. hepatica and flatworms. Phylogenetic analysis of CD59-like aa sequences from F. hepatica and flatworms showed that FhCD59-2 clustered with the known surface-associated protein SmCD59-2 of S. mansoni. Relatively well-supported clades specific to schistosomes, fasciolids and opisthorchiids were identified. The qPCR analysis of gene transcription showed that the relative expression of these 3 FhCD59-like sequences varied by 11-47-fold during fluke maturation, from the newly excysted juvenile (NEJ) to the adult stage. These findings suggest that different FhCD59-like sequences play distinct roles during the development of F. hepatica.
Characterisation of a DM domain-containing transcription factor from Trichostrongylus vitrinus (Nematoda: Strongylida)
Publisher: Elsevier BV
Date: 06-2006
DOI: 10.1016/J.PARINT.2005.10.007
Abstract: The sequence and expression profile of Tv-mab-23, a gene encoding a DM domain-containing protein from the parasitic nematode Trichostrongylus vitrinus, were investigated. The gene, containing an open reading frame (ORF) of 537 bp, encoded a predicted protein which had an overall amino acid identity of 45% to the MAB-23 molecule of the free-living nematode Caenorhabditis elegans. High levels of conservation were particularly predominant at the amino terminus of the proteins, with 86% identity over the first 58 amino acid residues in a region containing the highly conserved zinc module of the DM domain and conserved regions of the recognition helix of DM domain-containing transcription factors. Tv-mab-23 was expressed in a stage-specific manner in T. vitrinus. The highest levels of expression in fourth stage larvae coincide with the period in which profound gender-specific alterations in physiology occur in both the parasitic and free-living nematodes.
Structure and organization of the mitochondrial genome of the canine heartworm, Dirofilaria immitis
Publisher: Cambridge University Press (CUP)
Date: 07-2003
DOI: 10.1017/S0031182003003275
Abstract: This study determined the complete mitochondrial (mt) genome sequence of the canine heartworm, Dirofilaria immitis, and compared its structure, organization and other characteristics with Onchocerca volvulus and other secernentean nematodes. The D. immitis mt genome is 13814 bp in size and contains 36 of the 37 genes typical of metazoan organisms, and lacks the ATP synthetase subunit 8 gene. All of the genes are transcribed in the same direction. For the entire genome, the nucleotide contents are approximately 55% (T), approximately 19% (each for A and G) and approximately 7% (C), which is very similar to those of the protein-coding genes. In the latter genes, most (approximately 69%) third codon positions have a T, but rarely (approximately 1-9%) have an A or a C. The C content (8-12%) is higher at the first and second codon positions compared with the third position (approximately 1%). These nucleotide biases have a significant effect on the codon usage patterns and, thus, on the amino acid composition of the proteins. The mt genome organization of D. immitis is essentially the same as that of O. volvulus, but is distinctly different from other secernentean nematodes sequenced thus far. Irrespective of transpositions of transfer RNA (trn) genes and the non-coding, AT-rich region, there are 4 gene- or gene block-translocations between the mt genome of D. immitis and those of Caenorhabditis elegans, Ascaris suum and the 2 human hookworms, Ancylostoma duodenale and Necator americanus. For D. immitis, the 22 trn genes have secondary structures typical of other secernentean nematodes, and possess a TV-replacement loop instead of a TpsiC arm and loop. Like O. volvulus, the mt trnK and trnP of D. immitis use the anticodons CUU and AGG, whereas in other nematodes, UUU and UGG are employed, respectively. Also, the secondary structures of the 2 ribosomal RNA (rrn) genes are similar to the models for other nematodes. Overall, the availability of the complete D. immitis mt genome sequence provides a resource for future studies of the comparative mt genomics and of the population genetics and/or phylogeny of parasitic nematodes.
Genetic variation within the Hypodontus macropi (Nematoda: Strongyloidea) complex from macropodid marsupial hosts in Australia
Publisher: Wiley
Date: 12-2012
Abstract: Genetic variation was investigated in the strongylid nematode Hypodontus macropi from macropodid marsupials using the second internal transcribed spacer of ribosomal DNA. A total of 547 specimens from ten species of hosts, representing all of the known hosts of the parasite, from across the Australian continent was examined. Phylogenetic analyses revealed distinct genetic clades in each of Macropus agilis, M. dorsalis, M. rufogriseus, M. bicolor, Petrogale persephone, Thylogale billardierii and T. stigmatica. A further clade contained all specimens from M. robustus and M. rufus, together with two ex les of host switching by nematodes into M. fuliginosus. The latter clade was sub ided into three subclades, one comprising specimens occurring in M. robustus erubescens, M. rufus and M. fuliginosus, the second in M. r. woodwardi and the third in M. r. robustus suggesting a relationship between the subclades and the subspecies of M. robustus. The extent of the genetic differences and the fact that several of them occur in broad sympatry suggests that H. macropi as currently defined morphologically may represent as many as ten cryptic species. Limited evidence was found for co-speciation between hosts and parasites rather most relationships were better explained by host switching.
Structural and developmental expression of Ss-riok-2, an RIO protein kinase encoding gene of Strongyloides stercoralis
Publisher: Springer Science and Business Media LLC
Date: 18-08-2017
DOI: 10.1038/S41598-017-07991-2
Abstract: RIO kinases are essential atypical protein kinases in erse prokaryotic and eukaryotic organisms, playing significant roles in yeast and humans. However, little is known about their functions in parasitic nematodes. In the present study, we have isolated and characterized the full-length cDNA, gDNA and a putative promoter of a RIOK-2 protein kinase ( Ss -RIOK-2) encoding gene ( Ss-riok- 2) from Strongyloides stercoralis , a medically important parasitic nematode (Order Rhabditida). A three-dimensional structure (3D) model of Ss- RIOK-2 was generated using the Chaetomium thermophilum RIOK-2 protein kinase ( Ct- RIOK-2) crystal structure 4GYG as a template. A docking study revealed some critical sites for ATP binding and metal binding. The putative promoter of Ss-riok-2 contains a number of conserved elements. RNAseq analysis revealed the highest levels of the Ss-riok-2 transcript in free-living females and parasitic females. To identify anatomical patterns of Ss-riok-2 expression in S. stercoralis , we observed expression patterns of a transgene construct encoding green fluorescent protein under the Ss-riok-2 promoter in post free-living S. stercoralis . Expression driven by this promoter predominated in intestinal cells. This study demonstrates significant advancement in molecular and cellular biological study of S. stercoralis and of parasitic nematodes generally, and provides a foundation for further functional genomic studies.
Infection with the carcinogenic human liver fluke, Opisthorchis viverrini
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0MB00295J
Genetic diversity in the C-terminus of merozoite surface protein 1 among Plasmodium knowlesi isolates from Selangor and Sabah Borneo, Malaysia
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.MEEGID.2017.06.019
Abstract: Plasmodium knowlesi, a malaria parasite of macaques, has emerged as an important parasite of humans. Despite the significance of P. knowlesi malaria in parts of Southeast Asia, very little is known about the genetic variation in this parasite. Our aim here was to explore sequence variation in a molecule called the 42kDa merozoite surface protein-1 (MSP-1), which is found on the surface of blood stages of Plasmodium spp. and plays a key role in erythrocyte invasion. Several studies of P. falciparum have reported that the C-terminus (a 42kDa fragment) of merozoite surface protein-1 (MSP-1
Class II myosins in nematodes — genetic relationships, fundamental and applied implications
Publisher: Elsevier BV
Date: 05-2006
DOI: 10.1016/J.BIOTECHADV.2005.12.004
Abstract: Myosins are represented by a wide range of different classes of molecule, of which the most extensively studied are the class II myosins which drive muscle contraction and cell organization the functional unit of class II myosins comprises two myosin heavy chains (MHCs). This minireview gives an update on class II MHCs of nematodes and describes a comparative analysis of MHC genes from nematodes and other organismal groups. Genetic analyses of sequence data for the four functional domains of MHCs (i.e., the SH3-like N-terminal, head, neck and tail domains) reveal a delineation between both the nematode and non-nematode myosins and between muscle and non-muscle myosins. The distinctiveness of the MHCs of nematodes suggests functional and tissue specialization. The elucidation of the functional roles of myosins and other molecules in specific signaling pathways in nematodes has the potential to lead to new intervention strategies for parasites via the specific disruption or interruption of key developmental processes, having biotechnological implications in the longer term.
The Challenge of Developing a Single-Dose Treatment for Scabies
Publisher: Elsevier BV
Date: 11-2019
Abstract: Scabies is a common skin disease with an estimated worldwide incidence of 200 million people infected per year. Its morbidity and mortality is principally due to secondary bacterial infections, a link now well recognized and prompting the recent inclusion of this disease-complex in the WHO list of neglected tropical diseases. The few treatments available are poorly effective against Sarcoptes scabiei eggs and appear to induce resistance in the parasite. An ideal alternative would be a single-dose regimen that kills all developmental stages, including eggs. Drugs used in the veterinary field and applied to other arthropods could be tested experimentally in an established pig-scabies model. Moreover, functional genomics combined with target validation through biochemical research should assist in identifying new drugs.
Using UHPLC–MS profiling for the discovery of new sponge-derived metabolites and anthelmintic screening of the NatureBank bromotyrosine library
Publisher: Beilstein Institut
Date: 15-11-2022
DOI: 10.3762/BJOC.18.164
Abstract: In order to further expand the NatureBank open access compound library, chemical investigations of the Australian marine sponge, Ianthella basta, were undertaken since UHPLC–MS analysis of the extract from this sponge indicated the presence of a new alkaloid. Large-scale extraction and mass-directed isolation studies on the CH 2 Cl 2 /MeOH I. basta extract resulted in the purification of a new bromotyrosine-derived alkaloid, 5-debromopurealidin H ( 1 ), along with the known marine natural product, ianthesine E ( 2 ). The chemical structure of the new compound was determined following detailed spectroscopic and spectrometric data analysis. These two compounds ( 1 and 2 ) along with seven previously reported marine bromotyrosine alkaloids from the NatureBank open access library, which included psammaplysins F ( 3 ) and H ( 4 ), bastadins 4 ( 5 ), 8 ( 6 ) and 13 ( 7 ), aerothionin ( 8 ) and hexadellin A ( 9 ), were evaluated for their nematocidal activity against exsheathed third-stage larvae of Haemonchus contortus , a highly pathogenic parasite of ruminants. Of the nine compounds, bastadin 8 ( 6 ), hexadellin A ( 9 ) and bastadin 4 ( 5 ) showed inhibition towards larval motility after 72 h of exposure with IC 50 values of 1.6 µM, 10.0 µM and 33.3 µM, respectively.
Sequencing and Annotation of Mitochondrial Genomes from Individual Parasitic Helminths
Publisher: Springer New York
Date: 07-10-2014
DOI: 10.1007/978-1-4939-1438-8_3
Abstract: Mitochondrial (mt) genomics has significant implications in a range of fundamental areas of parasitology, including evolution, systematics, and population genetics as well as explorations of mt biochemistry, physiology, and function. Mt genomes also provide a rich source of markers to aid molecular epidemiological and ecological studies of key parasites. However, there is still a paucity of information on mt genomes for many metazoan organisms, particularly parasitic helminths, which has often related to challenges linked to sequencing from tiny amounts of material. The advent of next-generation sequencing (NGS) technologies has paved the way for low cost, high-throughput mt genomic research, but there have been obstacles, particularly in relation to post-sequencing assembly and analyses of large datasets. In this chapter, we describe protocols for the efficient lification and sequencing of mt genomes from small portions of in idual helminths, and highlight the utility of NGS platforms to expedite mt genomics. In addition, we recommend approaches for manual or semi-automated bioinformatic annotation and analyses to overcome the bioinformatic "bottleneck" to research in this area. Taken together, these approaches have demonstrated applicability to a range of parasites and provide prospects for using complete mt genomic sequence datasets for large-scale molecular systematic and epidemiological studies. In addition, these methods have broader utility and might be readily adapted to a range of other medium-sized molecular regions (i.e., 10-100 kb), including large genomic operons, and other organellar (e.g., plastid) and viral genomes.
Translational Research of Zoonotic Parasites: Toward Improved Tools for Diagnosis, Treatment and Control
Publisher: MDPI AG
Date: 11-2021
DOI: 10.3390/PATHOGENS10111416
Abstract: A range of factors, including social, demographic and economic transformation and human-induced environmental changes, are influencing the emergence or re-emergence of zoonoses, posing new challenges in how we detect, treat and prevent such diseases [...]
Targeted Isolation of Antibiotic Brominated Alkaloids from the Marine Sponge Pseudoceratina durissima Using Virtual Screening and Molecular Networking
Publisher: MDPI AG
Date: 29-08-2022
DOI: 10.3390/MD20090554
Abstract: Many targeted natural product isolation approaches rely on the use of pre-existing bioactivity information to inform the strategy used for the isolation of new bioactive compounds. Bioactivity information can be available either in the form of prior assay data or via Structure Activity Relationship (SAR) information which can indicate a potential chemotype that exhibits a desired bioactivity. The work described herein utilizes a unique method of targeted isolation using structure-based virtual screening to identify potential antibacterial compounds active against MRSA within the marine sponge order Verongiida. This is coupled with molecular networking-guided, targeted isolation to provide a novel drug discovery procedure. A total of 12 previously reported bromotyrosine-derived alkaloids were isolated from the marine sponge species Pseudoceratina durissima, and the compound, (+)-aeroplysinin-1 (1) displayed activity against the MRSA pathogen (MIC: µg/mL). The compounds (1–3, 6 and 9) were assessed for their central nervous system (CNS) interaction and behavioral toxicity to zebrafish (Danio rerio) larvae, whereby several of the compounds were shown to induce significant hyperactivity. Anthelmintic activity against the parasitic nematode Haemonchus contorutus was also evaluated (2–4, 6–8).
Deep insights into Dictyocaulus viviparus transcriptomes provides unique prospects for new drug targets and disease intervention
Publisher: Elsevier BV
Date: 05-2011
PROST: AlphaFold2-aware Sequence-Based Predictor to Estimate Protein Stability Changes upon Missense Mutations
Publisher: American Chemical Society (ACS)
Date: 16-08-2022
Abstract: An essential step in engineering proteins and understanding disease-causing missense mutations is to accurately model protein stability changes when such mutations occur. Here, we developed a new sequence-based predictor for the
HcSTK, a Caenorhabditis elegans PAR-1 homologue from the parasitic nematode, Haemonchus contortus
Publisher: Elsevier BV
Date: 06-2002
DOI: 10.1016/S0020-7519(02)00008-5
Abstract: A putative serine/threonine protein kinase (HcSTK) from the parasitic nematode Haemonchus contortus was characterised at the mRNA and amino acid levels. HcSTK displays a high level of identity (85-93% in the catalytic domain) with proteins of the PAR-1/MARK serine/threonine protein kinase (STK) subfamily, which represent signal transduction molecules involved in establishing and maintaining polarity in proliferating and differentiating cells. The transcript of hcstk is expressed in different developmental stages (second-, third-, fourth-stage larvae and adults) and various organs (muscle, intestine and reproductive) of H. contortus. In addition, there are several isoforms which appear to relate to a single gene. The expression profile of hcstk is similar to that of Caenorhabditis elegans PAR-1, and the level of sequence identity among members of the PAR-1/MARK STK subfamily, representing a range of species of vertebrates (e.g. humans and rodents), invertebrates (e.g. insects and C. elegans) and yeast, suggests that HcSTK may be involved in a conserved signal transduction pathway.
Organometallic Derivatization of the Nematocidal Drug Monepantel Leads to Promising Antiparasitic Drug Candidates
Publisher: Wiley
Date: 05-10-2016
Abstract: The discovery of novel drugs against animal parasites is in high demand due to drug-resistance problems encountered around the world. Herein, the synthesis and characterization of 27 organic and organometallic derivatives of the recently launched nematocidal drug monepantel (Zolvix
Morphological variability withinOesophagostomum bifurcumamong different primate species from Ghana
Publisher: Cambridge University Press (CUP)
Date: 12-2006
DOI: 10.1017/JOH2006363
Abstract: Adult Oesophagostomum bifurcum (Nematoda: Strongylida) from human and non-human primates from Ghana were compared in order to investigate the extent of morphological variability within the species. Using analysis of variance and principal component analysis, significant differences in morphological characters (such as parasite length, width, length of the oesophagus and length of spicules) were demonstrated between O. bifurcum worms from humans, the Mona, Patas or Green monkey and/or Olive baboons. These findings suggest that O. bifurcum from different species of primate host represent distinct population variants, also supported by recent epidemiological and genetic studies of O. bifurcum from such hosts.
Interactive online application for the prediction, ranking and prioritisation of drug targets in Schistosoma haematobium
Publisher: Springer Science and Business Media LLC
Date: 27-11-2018
Specific identification of Habronema microstoma and Habronema muscae (Spirurida, Habronematidae) by PCR using markers in ribosomal DNA
Publisher: Elsevier BV
Date: 08-2004
Molecular characterization of anisakid nematode larvae from 13 species of fish from Western Australia
Publisher: Elsevier BV
Date: 02-2013
DOI: 10.1016/J.IJFOODMICRO.2012.12.012
Abstract: This study characterized anisakid nematodes in estuarine and near-shore species of fish in southern Western Australia. A total of 108 fish representing 13 species were examined for anisakid larvae. For the molecular characterization of anisakid larvae (n=218), we used PCR-coupled mutation scanning-sequencing-phylogenetic analyses of sequence variation in the internal transcribed spacers of nuclear ribosomal DNA. With the exception of Sillaginoides punctatus and Sillago schomburgkii, all the fish species examined (Aldrichetta forsteri, Arripis georgianus, Hyporh hus regularis, Mugil cephalus, Platycephalus speculator, Pomatomus saltatrix, Pseudocaranx dentex, Pseudocaranx wrighti, Thysanophrys cirronatus, Trachurus novaezeelandiae and Upeneichthys lineatus) harboured at least one species of anisakid. Mutation scanning analysis identified 11 different genotypes of anisakid larvae. Phylogenetic analyses of the sequence data, employing reference sequence data for a wide range of anisakids (31 species) from public databases, revealed the presence of Anisakis pegreffii (n=3), Contracaecum multipapillatum (49), Contracaecum ogmorhini (1), Hysterothylacium larval type IV (82), Hysterothylacium larval type Vb (14), Hysterothylacium larval type VIII (3), Hysterothylacium larval type X (65), and Terranova type I (1) in the fish examined. The present study provides valuable information on the ersity of anisakids in southern Western Australia and also a basis for future investigations to assess the public health significance of these parasites.
Cryptosporidium - Biotechnological advances in the detection, diagnosis and analysis of genetic variation
Publisher: Elsevier BV
Date: 07-2008
DOI: 10.1016/J.BIOTECHADV.2008.02.003
Abstract: Cryptosporidiosis is predominantly a gastrointestinal disease of humans and other animals, caused by various species of protozoan parasites representing the genus Cryptosporidium. This disease, transmitted mainly via the faecal-oral route (in water or food), is of major socioeconomic importance worldwide. The diagnosis and genetic characterization of the different species and population variants (usually recognised as "genotypes" or "subgenotypes") of Cryptosporidium is central to the prevention, surveillance and control of cryptosporidiosis, particularly given that there is presently no broadly applicable treatment regimen for this disease. Although traditional phenotypic techniques have had major limitations in the specific diagnosis of cryptosporidiosis, there have been major advances in the development of molecular analytical and diagnostic tools. This article provides a concise account of Cryptosporidium and cryptosporidiosis, and focuses mainly on recent advances in nucleic acid-based approaches for the diagnosis of cryptosporidiosis and analysis of genetic variation within and among species of Cryptosporidium. These advances represent a significant step toward an improved understanding of the epidemiology as well as the prevention and control of cryptosporidiosis.
Advances in the diagnosis of key gastrointestinal nematode infections of livestock, with an emphasis on small ruminants
Publisher: Elsevier BV
Date: 12-2013
Genetic characterization of three unique operational taxonomic units of Eimeria from chickens in Australia based on nuclear spacer ribosomal DNA
Publisher: Elsevier BV
Date: 04-2008
DOI: 10.1016/J.VETPAR.2007.12.028
Abstract: Coccidiosis of chickens is one of the commonest and economically most important parasitic diseases of poultry worldwide. Given the limitations of traditional approaches, molecular tools have been developed for the specific diagnosis of coccidiosis. Recently, a polymerase chain reaction (PCR)-based capillary electrophoresis (CE) method, employing genetic markers in the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA, was established for both analytical and diagnostic purposes. The application of this method to investigate the epidemiology of coccidiosis and genetic structures of Eimeria populations on commercial chicken establishments has discovered genetic variants of Eimeria (i.e., new operational taxonomic units OTU-X, OTU-Y and OTU-Z) which were (based on CE analysis) distinct from those of species of Eimeria identified previously in chickens in Australia. The present characterization of these OTUs, based on their ITS-2 sequences and phylogenetic analyses of selected sequence data, provides first evidence to support that OTU-X represents a population variant of Eimeria maxima, and that OTU-Y and OTU-Z represent cryptic species of Eimeria. Further biological and genetic studies are needed to rigorously test these proposals and establish the specific status of these OTUs and their importance as pathogens in chickens. An understanding of the epidemiology of these population variants or cryptic species in Australia is central to designing and implementing effective vaccination and control strategies.
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