ORCID Profile
0000-0002-9268-7641
Current Organisation
Moredun Research Institute
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Wiley
Date: 30-10-2014
DOI: 10.1111/PIM.12132
Abstract: Ectoparasites present a major challenge for disease management globally. With drug resistance increasingly observed in many disease-causing species, the need for novel control measures is pressing. Ever-expanding genomic resources from 'next generation' sequencing are now available for a number of arthropod ectoparasites, necessitating an effective means of screening these data for novel candidates for vaccine antigens or targets for chemotherapeutics. Such in vitro screening methods must be developed if we are to make discoveries in a timely and cost-effective manner. This review will discuss the potential that RNA interference (RNAi) has demonstrated thus far in the context of arthropod ectoparasites and the potential roles for this technology in the development of novel methods for parasite control.
Publisher: Elsevier BV
Date: 10-2011
DOI: 10.1016/J.MCP.2011.09.002
Abstract: Early stages of sheep scab, the disease caused by the non-burrowing mite Psoroptes ovis, are often sub-clinical, or can be mis-diagnosed. A diagnostic test capable of detecting early disease and latent infestations is therefore highly desirable in disease control. This paper describes the design and validation of an ELISA, which incorporates a recombinant P. ovis antigen (Pso o 2), for the early detection of anti-P. ovis serum antibodies in sheep. This ELISA was evaluated using sera from sheep infested with P. ovis (n = 58) and sheep (n = 433) with no P. ovis infestation as well as sheep infected with other parasites including gastrointestinal nematodes (GIN), or chewing lice. A receiver operating characteristic (ROC) curve analysis was generated using the ELISA results for 491 sheep sera with the area under the curve (AUC) being 0.97. An optimal OD(450) cut-off of >0.06 absorbance units gave a test sensitivity of 0.93 and specificity of 0.90. The Pso o 2-based ELISA was able to detect specific antibodies to P. ovis during early experimental infestation prior to disease patency, indicating its utility for detecting sub-clinical infestation.
Publisher: Springer Science and Business Media LLC
Date: 04-01-2012
Abstract: The lack of genomic data available for mites limits our understanding of their biology. Evolving high-throughput sequencing technologies promise to deliver rapid advances in this area, however, estimates of genome size are initially required to ensure sufficient coverage. Quantitative real-time PCR was used to estimate the genome sizes of the burrowing ectoparasitic mite Sarcoptes scabiei , the non-burrowing ectoparasitic mite Psoroptes ovis , and the free-living house dust mite Dermatophagoides pteronyssinus . Additionally, the chromosome number of S. scabiei was determined by chromosomal spreads of embryonic cells derived from single eggs. S. scabiei cells were shown to contain 17 or 18 small ( 2 μM) chromosomes, suggesting an XO sex-determination mechanism. The average estimated genome sizes of S. scabiei and P. ovis were 96 (± 7) Mb and 86 (± 2) Mb respectively, among the smallest arthropod genomes reported to date. The D. pteronyssinus genome was estimated to be larger than its parasitic counterparts, at 151 Mb in female mites and 218 Mb in male mites. This data provides a starting point for understanding the genetic organisation and evolution of these astigmatid mites, informing future sequencing projects. A comparitive genomic approach including these three closely related mites is likely to reveal key insights on mite biology, parasitic adaptations and immune evasion.
Publisher: American Society for Microbiology
Date: 08-11-2018
DOI: 10.1128/MRA.01221-18
Abstract: The poultry red mite, Dermanyssus gallinae , is a major worldwide concern in the egg-laying industry. Here, we report the first draft genome assembly and gene prediction of Dermanyssus gallinae , based on combined PacBio and MinION long-read de novo sequencing.
Publisher: Public Library of Science (PLoS)
Date: 07-09-2011
Publisher: Springer Science and Business Media LLC
Date: 2013
Publisher: American Society for Microbiology
Date: 19-04-2018
Abstract: Sheep scab, caused by infestation with Psoroptes ovis , is highly contagious, results in intense pruritus, and represents a major welfare and economic concern. Here, we report the first draft genome assembly and gene prediction of P. ovis based on PacBio de novo sequencing. The ∼63.2-Mb genome encodes 12,041 protein-coding genes.
Publisher: Cold Spring Harbor Laboratory
Date: 14-04-2021
DOI: 10.1101/2021.04.14.439672
Abstract: Obligate blood-sucking arthropods rely on symbiotic bacteria to provision essential B vitamins that are either missing or at sub-optimal amounts in their nutritionally challenging blood diet. The poultry red mite Dermanyssus gallinae , an obligate blood-feeding ectoparasite, is primarily associated with poultry and a serious threat to the hen egg industry. Thus far, the identity and biological role of nutrient provisioning bacterial mutualists from D. gallinae are little understood. Here, we demonstrate that a Rickettsiella Gammaproteobacteria in maternally transmitted in D. gallinae and universally present in D. gallinae mites collected at different sites throughout Europe. In addition, we report the genome sequence of uncultivable endosymbiont “ Candidatus Rickettsiella rubrum” from D. gallinae eggs. The endosymbiont has a circular 1. 89 Mbp genome that encodes 1973 protein. Phylogenetic analysis confirms the placement R. rubrum within the Rickettsiella genus, closely related to a facultative endosymbiont from the pea aphid and Coxiella -like endosymbionts from blood feeding ticks. Analysis of the R. rubrum genome reveals many protein-coding sequences are either pseudogenized or lost, but R. rubrum has retained several B vitamin biosynthesis pathways, confirming the importance of these pathways in evolution of its nutritional symbiosis with D. gallinae. In silico metabolic pathway reconstruction revealed that R. rubrum is unable to synthesise protein amino acids and therefore these nutrients are likely provisioned by the host. In contrast R. rubrum retains biosynthetic pathways for B vitamins: thiamine (vitamin B1) via the salvage pathway riboflavin (vitamin B2) and pyridoxine (vitamin B6) and the cofactors: flavin adenine dinucleotide (FAD) and coenzyme A (CoA) that likely provision these nutrients to the host. We propose that bacterial symbionts which are essential to blood-feeding arthropod survival provide attractive targets for the development of novel control methods.
Publisher: Springer Science and Business Media LLC
Date: 22-07-2011
Publisher: Elsevier BV
Date: 02-2012
DOI: 10.1016/J.MCP.2011.07.002
Abstract: Some conventional methods of diagnosis of ectoparasite infections can have low sensitivity and/or specificity. In addition, early infestations, sub-clinical and carrier hosts often go un-diagnosed, allowing infestations to spread. This review focuses on the important ectoparasites of human, livestock and companion animals for which improved diagnostic tools are either already in use, or in development. These advances in diagnostic technologies have resulted in improved treatment, control and preventative strategies for many ectoparasitic diseases. Immunodiagnostic methods have had a large impact, with the emergence of highly sensitive and specific enzyme-linked immunosorbent assays (ELISAs) for sarcoptic and psoroptic mange, with further improved tests in development. In the present review, the advantages and limitations of such tests are discussed and the potential for future development explored. The increasing use of molecular tools, for ex le, PCR and other molecular methods, has improved our understanding of the epidemiology of ectoparasitic diseases, with practical consequences for community-based control programmes. Recently, the identification of specific signalling pathways during the host response to ectoparasites has led to the identification of disease biomarkers which, along with new technologies, such as multiplexed assays and microfluidic platforms, could lead to more cost-effective, rapid and accurate diagnosis of infectious diseases.
Publisher: Springer Science and Business Media LLC
Date: 10-06-2017
Publisher: Springer Science and Business Media LLC
Date: 10-01-2012
Publisher: Public Library of Science (PLoS)
Date: 03-08-2012
Publisher: Springer Science and Business Media LLC
Date: 03-08-2017
DOI: 10.1038/S41598-017-07092-0
Abstract: Metazoan parasites have to survive in many different niches in order to complete their life-cycles. In the absence of reliable methods to manipulate parasite genomes and/or proteomes, identification of the molecules critical for parasite survival within these niches has largely depended on comparative transcriptomic and proteomic analyses of different developmental stages of the parasite however, changes may reflect differences associated with transition between developmental stages rather than specific adaptations to a particular niche. In this study, we compared the transcriptome of two fourth-stage larval populations of the nematode parasite, Teladorsagia circumcincta , which were of the same developmental stage but differed in their location within the abomasum, being either mucosal-dwelling (MD) or lumen-dwelling (LD). Using RNAseq, we identified 57 transcripts which were significantly differentially expressed between MD and LD larvae. Of these transcripts, the majority (54/57) were up-regulated in MD larvae, one of which encoded for an ShKT-domain containing protein, Tck6, capable of modulating ovine T cell cytokine responses. Other differentially expressed transcripts included homologues of ASP-like proteins, proteases, or excretory-secretory proteins of unknown function. Our study demonstrates the utility of niche- rather than stage-specific analysis of parasite transcriptomes to identify parasite molecules of potential importance for survival within the host.
Publisher: Springer Science and Business Media LLC
Date: 2013
Publisher: Springer Science and Business Media LLC
Date: 11-02-2013
Abstract: Sheep scab is an intensively pruritic, exudative and allergic dermatitis of sheep caused by the ectoparasitic mite Psoroptes ovis . The purpose of the present study was to investigate the effect of P. ovis infestation on different components of the ovine epidermal barrier within the first 24 hours post-infestation (hpi). To achieve this, the expression of epidermal differentiation complex (EDC) genes and epidermal barrier proteins, the nature and severity of epidermal pathology and transepidermal water loss (TEWL) were evaluated. By 1 hpi a significant dermal polymorphonuclear infiltrate and a significant increase in TEWL with maximal mean TEWL (598.67 g/m 2 h) were observed. Epidermal pathology involving intra-epidermal pustulation, loss of epidermal architecture and damage to the basement membrane was seen by 3 hpi. Filaggrin and loricrin protein levels in the stratum corneum declined significantly in the first 24 hpi and qPCR validation confirmed the decrease in expression of the key EDC genes involucrin , filaggrin and loricrin observed by microarray analysis, with 5.8-fold, 4.5-fold and 80-fold decreases, respectively by 24 hpi. The present study has demonstrated that early P. ovis infestation disrupts the ovine epidermal barrier causing significant alterations in the expression of critical barrier components, epidermal pathology, and TEWL. Many of these features have also been documented in human and canine atopic dermatitis suggesting that sheep scab may provide a model for the elucidation of events occurring in the early phases of atopic sensitisation.
Publisher: Elsevier BV
Date: 06-2013
DOI: 10.1016/J.MCP.2013.03.003
Abstract: Sheep scab, caused by the highly contagious mite Psoroptes ovis, is endemic in a number of sheep-producing countries worldwide, and is a major animal welfare and economic concern. Recent developments in the diagnosis of sheep scab include a highly sensitive and specific serum antibody-based assay which can be used to indicate exposure to the parasite but not necessarily current disease status. Here, a transcriptomic and bioinformatics analysis of the circulating leukocytes of sheep with active P. ovis infestation indicated that the transcription levels of complement 4 binding protein beta (C4BPB) increased by 12 fold from pre-infestation to 6 weeks post-infestation. Semi-quantitative studies confirmed increased serum C4BPB protein levels in sheep infested with P. ovis. To quantify this serum protein response and characterize ovine C4BPB as a biomarker for active P. ovis infestation, the ovine C4BPB gene was sequenced, a recombinant protein expressed, antibodies against this protein were raised in rabbits and a sandwich ELISA developed. The results from this assay indicated that serum C4BPB protein levels increased 4-fold from pre-infestation to 6 weeks post-infestation, which demonstrated the potential of the assay to quantify C4BPB in sheep sera and indicated the potential of C4BPB as a biomarker of current disease status in sheep post-infestation and post-treatment.
Publisher: Springer Science and Business Media LLC
Date: 09-02-2016
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.MCP.2015.07.008
Abstract: This is the first report of gene silencing by RNA interference (RNAi) in the European house dust mite, Dermatophagoides pteronyssinus, Trouessart, 1897. Using a non-invasive immersion method first developed for the honey bee mite, Varroa destructor, a significant reduction in the expression of D. pteronyssinus glutathione-S-transferase mu-class 1 enzyme (DpGST-mu1) was achieved following overnight immersion in double stranded RNA encoding DpGST-mu1. Although no detrimental phenotypic changes were observed following silencing, this technique can now be used to address fundamental physiological questions and assess the potential therapeutic benefit in silencing D. pteronyssinus target genes in selected domestic situations of high human-mite interface.
Publisher: Springer Science and Business Media LLC
Date: 17-03-2012
DOI: 10.1007/S00441-012-1369-9
Abstract: Among arthropod pests, mites are responsible for considerable damage to crops, humans and other animals. However, detailed physiological data on these organisms remain sparse, mainly because of their small size but possibly also because of their extreme ersity. Focusing on intestinal proteases, we draw together information from three distinct mite species that all feed on skin but have separately adapted to a free-living, a strictly ecto-parasitic and a parasitic lifestyle. A wide range of studies involving immunohistology, molecular biology, X-ray crystallography and enzyme biochemistry of mite gut proteases suggests that these creatures have erged considerably as house dust mites, sheep scab mites and scabies mites. Each species has evolved a particular variation of a presumably ancestral repertoire of digestive enzymes that have become specifically adapted to their in idual environmental requirements.
Publisher: Cold Spring Harbor Laboratory
Date: 29-04-2021
DOI: 10.1101/2021.04.28.441781
Abstract: In iduals vary broadly in their response to vaccination and subsequent exposure to infection, causing persistence of both infection and transmission. The prevalence of poor vaccine responders h ers the development of vaccines, especially against parasitic helminths. Yet despite having substantial economic and societal impact, the immune mechanisms that underlie such variability, especially at the site of parasite infection, remain poorly understood. Previous trials using a prototype vaccine for the control of the gastric parasitic Teladorsagia circumcincta , one of the highest impact parasites affecting sheep, revealed substantial variation in protection between in iduals, which we hypothesised may in part be driven by age at vaccination. Here, to characterise how immunity at the mucosal site of infection developed in vaccinated lambs, we inserted gastric cannulae into the abomasa (true stomachs) of three-month- and six-month-old lambs before vaccination, and performed a longitudinal analysis of their local immune response during subsequent challenge infection. We found that the vaccine caused systemic changes in the baseline immune profile within the abomasum before any parasite exposure had occurred and reduced parasite burden and egg output once lambs were infected, regardless of age. However, age affected how vaccinated lambs responded to subsequent infection across multiple immune pathways, with only a minority of protective immune pathways being independent of age. This resulted in younger lambs being more susceptible to infection regardless of vaccine status. The identification of age-dependent (mostly adaptive) and age-independent (mostly innate) protective immune pathways should help refine the formulation of vaccines against these and potentially other helminth parasites of ruminants, and could indicate specificities of anti-helminth immunity more generally.
Publisher: Springer Science and Business Media LLC
Date: 10-11-2010
Publisher: Springer Science and Business Media LLC
Date: 11-2018
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for stewart burgess.