ORCID Profile
0000-0003-0400-9670
Current Organisation
Deutscher Wetterdienst
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Veterinary Sciences | Veterinary Virology | Veterinary Medicine | Animal Protection (Pests and Pathogens) | Veterinary Immunology | Animal protection (incl. pests and pathogens) | Veterinary Epidemiology | Veterinary virology | Virology | Veterinary Medicine | Veterinary sciences | Immunology |
Poultry | Veterinary Biological Preventatives (e.g. Vaccines) | Horses | Eggs | Poultry | Expanding Knowledge in the Agricultural and Veterinary Sciences | Minor livestock (e.g. horses, goats, deer) | Prevention—biologicals (e.g. vaccines) | Infectious Diseases
Publisher: American Society for Microbiology
Date: 2018
DOI: 10.1128/JVI.01534-17
Abstract: Infectious laryngotracheitis virus (ILTV) is an alphaherpesvirus that infects chickens, causing upper respiratory tract disease and significant losses to poultry industries worldwide. Glycoprotein G (gG) is a broad-range viral chemokine-binding protein conserved among most alphaherpesviruses, including ILTV. A number of studies comparing the immunological parameters between infection with gG-expressing and gG-deficient ILTV strains have demonstrated that expression of gG is associated with increased virulence, modification of the amount and the composition of the inflammatory response, and modulation of the immune responses toward antibody production and away from cell-mediated immune responses. The aims of the current study were to examine the establishment of infection and inflammation by ILTV and determine how gG influences that response to infection. In vitro infection studies using tracheal organ tissue specimen cultures and blood-derived monocytes and in vivo infection studies in specific-pathogen-free chickens showed that leukocyte recruitment to the site of infection is an important component of the induced pathology and that this is influenced by the expression of ILTV gG and changes in the transcription of the chicken orthologues of mammalian CXC chemokine ligand 8 (CXCL8), chicken CXCLi1 and chicken CXCLi2, among other cytokines and chemokines. The results from this study demonstrate that ILTV gG interferes with chemokine and cytokine transcription at different steps of the inflammatory cascade, thus altering inflammation, virulence, and the balance of the immune response to infection. IMPORTANCE Infectious laryngotracheitis virus is an alphaherpesvirus that expresses gG, a conserved broad-range viral chemokine-binding protein known to interfere with host immune responses. However, little is known about how gG modifies virulence and influences the inflammatory signaling cascade associated with infection. Here, data from in vitro and in vivo infection studies are presented. These data show that gG has a direct impact on the transcription of cytokines and chemokine ligands in vitro (such as chicken CXCL8 orthologues, among others), which explains the altered balance of the inflammatory response that is associated with gG during ILTV infection of the upper respiratory tract of chickens. This is the first report to associate gG with the dysregulation of cytokine transcription at different stages of the inflammatory cascade triggered by ILTV infection of the natural host.
Publisher: Springer Science and Business Media LLC
Date: 20-06-2017
DOI: 10.1007/S10393-017-1254-9
Abstract: Wild populations of the critically endangered woylie (Bettongia penicillata) recently declined by 90% in southwest Western Australia. Increased predation is the leading hypothesis for decline, but disease may be playing a role increasing susceptibility to predation. To explore this possibility, we surveyed woylie populations in the wild, in captivity and in a predator-free sanctuary for exposure to, and infection with, four known pathogens of macropods: herpesviruses, Wallal and Warrego orbiviruses, and Toxoplasma gondii. Our study found two of 68 in iduals positive for neutralizing antibodies against known macropodid alphaherpesviruses. Three of 45 in iduals were PCR positive for a herpesvirus that was shown to be a novel gammaherpesvirus or a new strain/variant of Potoroid Herpesvirus 1. Further sequence information is required to definitively determine its correct classification. There was no evidence of antibodies to orbivirus Wallal and Warrego serogroups, and all serological s les tested for T. gondii were negative. This is the first report of PCR and serological detection of herpesviruses in the woylie. Positive in iduals did not demonstrate clinical signs of herpesviral diseases therefore, the clinical significance of herpesviruses to wild woylie populations remains unclear. Further monitoring for herpesvirus infections will be important to inform disease risk analysis for this virus and determine temporal trends in herpesvirus activity that may relate to population health and conservation outcomes.
Publisher: Wiley
Date: 30-08-2022
DOI: 10.1111/AVJ.13202
Abstract: A molecular survey of herpesviruses in Australian native mammals was conducted, spanning 260 in iduals from 27 species. Among the herpesviruses detected, a putative new gammaherpesvirus species was detected in the yellow‐bellied glider ( Petaurus australis ), and another in the critically endangered Leadbeater's possum ( Gymnobelideus leadbeateri ). In addition, the known host range of the putative species macropodid gammaherpesvirus 3 (MaHV‐3) is herein extended to the western grey kangaroo ( Macropus fuliginosus ). These findings expand our understanding of herpesviruses in Australian mammals and may inform biosecurity protocols for captive and translocated populations.
Publisher: Springer Science and Business Media LLC
Date: 04-11-2010
Publisher: Elsevier BV
Date: 12-2011
DOI: 10.1016/J.VACCINE.2011.10.055
Abstract: Infectious laryngotracheitis virus (ILTV) is an alphaherpesvirus that causes acute respiratory disease in poultry. Live attenuated ILTV vaccines have been used extensively to help control outbreaks of disease. Two Australian-origin attenuated vaccine strains, SA2 and A20 ILTV, are commercially available and are in frequent use in Australia. Both these vaccines are of chicken embryo origin (CEO). The A20 ILTV strain was developed from the SA2 ILTV strain by sequential passage of SA2 ILTV in tissue culture in order to reduce its residual virulence. Previous studies in our laboratories have demonstrated the greater attenuation of A20 ILTV under controlled experimental conditions, but the genetic basis of the in vivo phenotypes of A20 and SA2 ILTV has not been elucidated. In this study, the genetic differences between A20 and SA2 ILTV were examined by performing complete genome sequencing and comparative analysis. The genome sequences were also compared to a reference sequence from another CEO ILTV vaccine (Serva ILTV: GenBank accession number HQ_630064) of European-origin. Additional in ovo studies to assess cell to cell spread were performed in order to allow further comparisons of the pathogenicity of SA2 and A20 ILTV. The sequencing results showed that the genome sizes of SA2 and A20 ILTV were 152,975 and 152,978bp, respectively, while Serva ILTV had a genome size of 152,630bp. The genomes of SA2 and A20 ILTV shared 99.9% nucleotide sequence identity with each other, but only 99.2% identity with Serva ILTV. In complete genome alignments between SA2 and A20 ILTV, a total of 24 single nucleotide polymorphisms (SNPs) were identified, but only two of these were non-synonymous. These were located in the ORF B and UL15 genes. Four indels were detected in non-coding regions. The findings from this study demonstrate the general genetic stability of ILTV, but also show that non-synonymous changes in the ORF B and UL15 genes have arisen following tissue culture passage of SA2 ILTV to produce the A20 vaccine. It is likely that these non-synonymous changes are related to the greater attenuation of A20 ILTV compared to SA2 ILTV, and to the reduced ability of A20 ILTV to spread from cell to cell, as observed in this study. The results from this study also demonstrate the ergence between the genomes of the Australian-origin ILTV vaccine strains and the Serva vaccine strain.
Publisher: Public Library of Science (PLoS)
Date: 14-09-2015
Publisher: Public Library of Science (PLoS)
Date: 02-05-2014
Publisher: Elsevier BV
Date: 12-2019
Abstract: Between 1991 and 2014 the per capita notification rate of salmonellosis in Australia increased from 31.9 to 69.7 cases per 100,000 people. Salmonella Typhimurium accounted for nearly half the human cases until the end of 2014. In this study, we used cluster analysis tools to compare S. Typhimurium isolates from a chicken-meat study with those reported to the National Enteric Pathogen Surveillance System (NEPSS) from the coincident human and non-human populations. There was limited phage type ersity within all populations and a lack of specificity of MLVA profiling within phage types. The chicken-meat study isolates were not significantly clustered with the human cases and at least 7 non-human sources, based on typing profiles (PT/MLVA combination), could be implicated as a source of human cases during the same period. In the absence of a strong surveillance system representative of all putative sources, MLVA and phage typing alone or in combination are insufficient to identify the source of human cases.
Publisher: American Society for Microbiology
Date: 14-01-2021
DOI: 10.1128/MRA.01189-20
Abstract: We present the genome sequences of macropodid alphaherpesviruses 2 and 4, two closely related pathogens of macropods. Both encoded 68 nonredundant open reading frames (ORFs) and share 90.6% genome-wide nucleotide identity. These viruses are associated with fatal outbreaks of disease in multiple marsupial species. These sequences will be important for the development of new diagnostic tools.
Publisher: Public Library of Science (PLoS)
Date: 18-03-2015
Publisher: Springer Science and Business Media LLC
Date: 12-11-2018
Publisher: Cold Spring Harbor Laboratory
Date: 12-01-2017
DOI: 10.1101/099945
Abstract: Koalas ( Phascolarctos cinereus ) are iconic Australian marsupials currently threatened by several processes. Infectious reproductive tract disease, caused by Chlamydia pecorum , and koala retrovirus infection are considered key drivers of population decline. The clinical sign of ‘wet bottom’, a staining of the rump associated with urinary incontinence, is often caused by chlamydial urogenital tract infections. However, wet bottom has been recorded in koalas free of C. pecorum , suggesting other causative agents in those in iduals. Current understanding of the bacterial community of the koala urogenital tract is limited. We used 16S rRNA ersity profiling to investigate the microbiome of the urogenital tract of ten female koalas. This was to produce baseline data on the female koala urogenital tract microbiome, and to undertake preliminary investigations of potential causative agents of wet bottom, other than C. pecorum . Five urogenital s les were processed from koalas presenting with wet bottom and five were clinically normal. We detected thirteen phyla across the ten s les, with Firmicutes occurring at the highest relative abundance (77.6%). The order Lactobacillales , within the Firmicutes , comprised 70.3% of the reads from all s les. After normalising reads using DESeq2 and testing for significant differences ( P 0.05), there were 25 operational taxonomic units (OTUs) more commonly found in one group over the other. The families Aerococcaceae and Tissierellaceae both had four significantly differentially abundant OTUs. These four Tissierellaceae OTUs were all significantly more abundant in koalas with wet bottom. This study provides an essential foundation for future investigations of both the normal microflora of the koala urogenital tract, and better understanding of the causes of koala urogenital tract disease. Koalas in the states of Queensland and New South Wales are currently undergoing decline, and have been classified as vulnerable populations. Urogenital tract disease is a leading cause of hospital admissions in these states, yet previously little was known of the normal flora of this site. Wet bottom is a clinical sign of urogenital tract disease, which is often assumed to be caused by C. pecorum and treated accordingly. Our research highlights that other organisms may be causing wet bottom, and these potential aetiological agents need to be further investigated to fully address the problems this species faces.
Publisher: Public Library of Science (PLoS)
Date: 24-05-2018
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.MEEGID.2016.12.022
Abstract: Recombination in alphaherpesviruses was first described more than sixty years ago. Since then, different techniques have been used to detect recombination in natural (field) and experimental settings. Over the last ten years, next-generation sequencing (NGS) technologies and bioinformatic analyses have greatly increased the accuracy of recombination detection, particularly in field settings, thus contributing greatly to the study of natural alphaherpesvirus recombination in both human and veterinary medicine. Such studies have highlighted the important role that natural recombination plays in the evolution of many alphaherpesviruses. These studies have also shown that recombination can be a safety concern for attenuated alphaherpesvirus vaccines, particularly in veterinary medicine where such vaccines are used extensively, but also potentially in human medicine where attenuated varicella zoster virus vaccines are in use. This review focuses on the contributions that NGS and sequence analysis have made over the last ten years to our understanding of recombination in mammalian and avian alphaherpesviruses, with particular focus on attenuated live vaccine use.
Publisher: Informa UK Limited
Date: 20-04-2017
DOI: 10.1080/03079457.2017.1311990
Abstract: Infection with Mycoplasma gallisepticum induces severe lymphoproliferative lesions in multiple sites along the respiratory tract in chickens and turkeys. These immunopathological responses have been well-characterized in chickens, but have not been studied closely in turkeys. The aim of the study described here was to examine the immune responses of turkeys after live vaccination and infection with M. gallisepticum. In a strain comparison study, the mean log
Publisher: Microbiology Society
Date: 03-04-2023
DOI: 10.1099/JGV.0.001836
Abstract: Infectious laryngotracheitis virus (ILTV an alphaherpesvirus) is a respiratory pathogen of chickens and causes significant economic losses in the poultry industry globally, in addition to severe animal health and welfare concerns. To date, studying the role of ILTV genes in viral infection, replication or pathogenesis has largely been limited to genes that can be deleted from the ILTV genome and the resultant deletion mutants characterized in vitro or in vivo . However, this approach is not suitable for the study of essential genes. This study trialled two different codon deoptimization techniques that aimed to separately disrupt and downregulate the expression of two ILTV genes, ICP8 and UL12, which are essential or very important in viral replication. The target genes were partially recoded using codon usage deoptimization (CUD) and codon pair bias deoptimization (CPBD) approaches and characterized in vitro . Viruses deoptimized via CPBD showed decreased protein expression as assessed by Western blotting and/or fluorescence microscopy to measure the intensity of the fluorescent marker fused to the target protein. Viruses deoptimized by CUD showed less consistent results, with some mutants that could not be generated or isolated. The results indicate that CPBD is an attractive and viable tool for the study of essential or critically important genes in ILTV. This is the first study, to our knowledge, that utilizes CPBD and CUD techniques for the study of ILTV genes.
Publisher: Wiley
Date: 2011
DOI: 10.1111/J.1751-0813.2010.00662.X
Abstract: A gammaherpesvirus was detected by polymerase chain reaction (PCR) in ocular, nasal and oropharyngeal swab s les collected from an adult free‐ranging male eastern grey kangaroo ( Macropus giganteus ) with clinical signs of severe respiratory disease. This is the first time a gammaherpesvirus has been detected in a free‐ranging macropod in Australia. The nucleotide sequence of a conserved region of the DNA polymerase gene of the detected virus showed a high degree of identity to a gammaherpesvirus recently detected in a zoological collection of eastern grey kangaroos in North America. The detection of this gammaherpesvirus in a free‐ranging, native eastern grey kangaroo provides evidence that this species is a natural host.
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.PREVETMED.2017.02.006
Abstract: Coxiella burnetii may cause reproduction disorders in pregnant animals but subclinical infection in other animals. Unrecognised disease may delay implementation of control interventions, resulting in transmission of infection to other livestock and to humans. Seroreactivity to C. burnetii phase-specific antigens, is routinely used to interpret the course of human Q fever. This approach could be similarly useful in identifying new and existing infections in livestock herds to help describe risk factors or production losses associated with the infections and the implementation of disease-control interventions. This study aimed to elucidate the dynamics of C. burnetii infections using seroreactivity to phase-specific antigens and to examine the impact of infection on milk yield in goats in an endemically-infected farm that was associated with a Q fever outbreak in Australia. Seroreactivity pre- and post-partum and milk yield were studied in 164 goats (86 nulliparous and 78 parous). Post-partum, the seroprevalence of antibodies to C. burnetti increased from 4.7% to 31.4% throughout goats' first kiddings and from 47.4% to 55.1% in goats kidding for the second or greater time. Of 123 goats that were seronegative pre-partum, 26.8% seroconverted over the three-month peri-partum period, highlighting the importance of controlling infection throughout this time. The risk of seroconversion was comparable in first or later kidders, suggesting constant risk irrespective of parity. No loss in milk production associated with seroconversion to phase 2 was observed within the first nine weeks of lactation. However, seroconversion to only phase 1 was associated with extra 0.276L of milk per day (95% Confidence Interval: 0.010, 0.543 P=0.042), which warrants further investigation to ascertain whether or not the association is causal. Further studies on seroreactivity and milk production over longer periods are required, as milk production loss caused by C. burnetti may be an additional reason to control the disease in goat herds.
Publisher: Wiley
Date: 20-09-2010
Publisher: Microbiology Society
Date: 02-2016
DOI: 10.1099/JMM.0.000416
Publisher: Springer Science and Business Media LLC
Date: 26-02-2006
DOI: 10.1007/S00705-005-0721-8
Abstract: In alphaherpesviruses, glycoprotein I (gI) and glycoprotein E (gE) form a heterodimer that functions in cell-to-cell spread of the virus. Generally, alphaherpesvirus mutants that lack these glycoproteins are replication competent in cell culture but show a reduced capacity for cell-to-cell spread and hence smaller plaque sizes. Infectious laryngotracheitis virus (ILTV), or Gallid herpesvirus 1, is an alphaherpesvirus that causes respiratory disease in chickens. The roles of gI and gE in ILTV have not been investigated previously. In this study, a glycoprotein I and glycoprotein E deletion mutant of ILTV (gI/gE-ve ILTV) was generated by replacing the region of the ILTV genome coding for the adjacent gI and gE genes with the gene for enhanced green fluorescent protein (eGFP). This gI/E-ve ILTV was readily propagated in cell culture in the presence of wildtype ILTV (wt ILTV). However, in the absence of wt ILTV the propagation of gI/gE-ve ILTV was severely impaired. Infection of permissive cell cultures with gI/gE-ve ILTV failed to produce plaques but single infected cells could be identified by fluorescence microscopy. This suggests that gI/gE has a more significant role in the cell-to-cell spread of ILTV in vitro than in many other alphaherpesviruses.
Publisher: Elsevier BV
Date: 05-2007
DOI: 10.1016/J.VACCINE.2007.01.080
Abstract: Infectious laryngotracheitis virus (ILTV), an alphaherpesvirus, causes respiratory disease in chickens and is currently controlled by vaccination with conventionally attenuated virus strains. These vaccines have limitations because of residual pathogenicity and reversion to virulence, suggesting that a novel vaccine strain that lacks virulence gene(s) may enhance disease control. Glycoprotein G (gG) has recently been identified as a virulence factor in ILTV. In this study the immunogenicity and relative pathogenicity of gG deficient ILTV was investigated in SPF chickens. Birds vaccinated with gG deficient ILTV were protected against clinical signs of disease following challenge with virulent ILTV and gG deficient ILTV was also shown to be less pathogenic than currently available commercial vaccine strains. Thus gG deficient ILTV appears to have potential as a vaccine candidate.
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.DCI.2013.03.022
Abstract: Infectious laryngotracheitis (ILT) is an upper respiratory tract disease in chickens caused by infectious laryngotracheitis virus (ILTV), an alphaherpesvirus. Despite the extensive use of attenuated, and more recently recombinant, vaccines for the control of this disease, ILT continues to affect the intensive poultry industries worldwide. Innate and cell-mediated, rather than humoral immune responses, have been identified as responsible for protection against disease. This review examines the current understandings in innate and adaptive immune responses towards ILTV, as well as the role of ILTV glycoprotein G in modulating the host immune response towards infection. Protective immunity induced by ILT vaccines is also examined. The increasing availability of tools and reagents for the characterisation of avian innate and cell-mediated immune responses are expected to further our understanding of immunity against ILTV and drive the development of new generation vaccines towards enhanced control of this disease.
Publisher: Informa UK Limited
Date: 04-05-2014
DOI: 10.1080/03079457.2014.914624
Abstract: The emergence of new variant strains of the poultry pathogen infectious bronchitis virus (IBV) is continually reported worldwide, owing to the labile nature of the large single-stranded RNA IBV genome. High resolution melt curve analysis previously detected a variant strain, N1/08, and the present study confirmed that this strain had emerged as a result of recombination between Australian subgroup 2 and 3 strains in the spike gene region, in a similar manner reported for turkey coronaviruses. The S1 gene for N1/08 had highest nucleotide similarity with subgroup 2 strains, which is interesting considering subgroup 2 strains have not been detected since the early 1990s. SimPlot analysis of the 7.2-kb 3' end of the N1/08 genome with the same region for other Australian reference strains identified the sites of recombination as immediately upstream and downstream of the S1 gene. A pathogenicity study in 2-week-old chickens found that N1/08 had similar pathogenicity for chicken respiratory tissues to that reported for subgroup 2 strains rather than subgroup 3 strains. The results of this study demonstrate that recombination is a mechanism utilized for the emergence of new strains of IBV, with the ability to alter strain pathogenicity in a single generation.
Publisher: Informa UK Limited
Date: 06-2013
DOI: 10.1080/03079457.2013.800634
Abstract: Over the past 80 years, biosecurity measures and vaccines have been used to prevent the occurrence of outbreaks of infectious laryngotracheitis (ILT). Despite these control strategies, ILT continues to have an impact on intensive poultry industries. Attenuated vaccines, particularly those derived by passage in chicken embryos, have been associated with a number of side effects, including residual virulence, transmission to naïve birds, establishment of latent infections with subsequent reactivation and shedding of virus, and reversion to virulence after in vivo passage. Most recently, recombination between attenuated ILT vaccines in the field has been shown to be responsible for the emergence of new virulent viruses that have caused widespread disease. To address some of these issues, new-generation virally vectored recombinant vaccines have been developed and recently released in some countries. In addition, recombinant deletion mutants of ILT virus have been proposed as vaccine candidates. In this review, recent advances in the understanding of the epidemiology of traditionally attenuated ILT vaccines as well as in the development and use of new generation vaccines are examined. Next-generation vaccines, along with more appropriate immunological screening strategies, are identified as particularly promising options to enhance ILT control in the future.
Publisher: Informa UK Limited
Date: 08-2011
DOI: 10.1080/03079457.2011.588686
Abstract: Infectious laryngotracheitis (ILT) is an acute respiratory disease in poultry that is commonly controlled by vaccination with conventionally attenuated virus strains. Despite the use of these vaccines, ILT remains a threat to the intensive poultry industry. Our laboratory has developed a novel candidate vaccine strain of infectious laryngotracheitis virus (ILTV) lacking glycoprotein G (ΔgG-ILTV). The aim of the present study was to directly compare this candidate vaccine with three currently available commercial vaccines in vivo. Five groups of specific-pathogen-free chickens were eye-drop inoculated with one of the three commercial vaccine strains (SA2-ILTV, A20-ILTV or Serva-ILTV), or ΔgG-ILTV, or sterile medium. Vaccine safety was assessed by examining clinical signs, weight gain and persistence of virus in the trachea. Vaccine efficacy was assessed by scoring clinical signs and conducting post-mortem analyses following challenge with virulent virus. Following vaccination, birds that received ΔgG-ILTV had the highest weight gain among the vaccinated groups and had clinical scores that were significantly lower than birds vaccinated with SA2-ILTV or A20-ILTV, but not significantly different from those of birds vaccinated with Serva-ILTV. Analysis of clinical scores, weight gain, tracheal pathology and virus replication after challenge revealed a comparable level of efficacy for all vaccines. Findings from this study further demonstrate the suitability of ΔgG-ILTV as a vaccine to control ILT.
Publisher: American Association of Avian Pathologists (AAAP)
Date: 03-2015
DOI: 10.1637/10810-030414-REG.1
Abstract: Infectious laryngotracheitis (ILT) is a significant upper respiratory tract disease of chickens with a worldwide distribution. Differentiating between wild-type and vaccine strains of ILT virus (ILTV) would be useful for enhancing disease control, and in the early stages of a disease outbreak molecular diagnostic tools for the detection and differentiation of the circulating virus could be applied. This study developed TaqMan real-time PCR (qPCR) assays to detect and differentiate the glycoprotein G (gG)-deficient (ΔgG) ILTV candidate vaccine strain of ILTV from ILTV strains that contain the gG gene. The gG+ve and gG-ve ILTV TaqMan assays were used in in idual and multiplex format to detect, differentiate, and quantitate ILTV DNA in laboratory and clinical s les. The assays were highly sensitive and highly specific, with a detection limit of 10 viral template copies for each assay. Low interassay coefficients of variation were recorded (0.021-0.042 and 0.013-0.039) for gG+ve and gG-ve TaqMan assays, respectively. The multiplex assay was successfully used to examine the replication kinetics of wild-type and ΔgG strains of ILTV in cultured leghorn male hepatoma cells and embryonated hen eggs under coinfection conditions. The results showed that the TaqMan qPCR assay, along with the ΔgG ILTV vaccine, has the potential to be used in a "Differentiating Infected from Vaccinated Animals" strategy for the control and eradication of ILT.
Publisher: Cambridge University Press (CUP)
Date: 28-03-2016
DOI: 10.1017/S0030605315001283
Abstract: The eastern bettong Bettongia gaimardi , a potoroid marsupial, has been extinct on the Australian mainland since the 1920s. Sixty adult bettongs were reintroduced from the island of Tasmania to two predator-free fenced reserves on mainland Australia. We examined baseline health parameters (body weight, haematology and biochemistry, parasites and infectious disease exposure) in a subset of 30 (13 male, 17 female) in iduals at translocation and again at 12–24 months post-reintroduction. The mean body weight increased significantly post-reintroduction but there were no significant differences in body weight between the two reintroduction sites or between the sexes in response to reintroduction. Differences were evident in multiple haematological and biochemical variables post-reintroduction but there were few differences between the two reintroduced populations or between the sexes in response to reintroduction. Ectoparasite assemblages differed, with five of 13 species failing to persist, and an additional four species were identified post-reintroduction. None of the bettongs had detectable antibodies to the alphaherpesviruses Macropodid herpesvirus 1 and 2 post-reintroduction, including one in idual that was seropositive at translocation. Similarly, the novel gammaherpesvirus potoroid herpesvirus 1 was not detected by polymerase chain reaction (PCR) in any of the bettongs post-reintroduction, including one in idual that was PCR-positive at translocation. None of the bettongs had detectable antibodies to Toxoplasma gondii either at translocation or post-reintroduction. Our data demonstrate changing baseline health parameters in eastern bettongs following reintroduction to the Australian mainland are suggestive of improved health in the reintroduced populations, and provide additional metrics for assessing the response of macropodoids to reintroduction.
Publisher: Elsevier BV
Date: 11-2012
DOI: 10.1016/J.VACCINE.2012.10.023
Abstract: Infectious laryngotracheitis virus (ILTV), an alphaherpesvirus, causes respiratory disease in chickens and is commonly controlled by vaccination with conventionally attenuated vaccines. Glycoprotein G (gG) is a virulence factor in ILTV and a gG deficient strain of ILTV (ΔgG-ILTV) has shown potential for use as a vaccine. In the poultry industry vaccination via drinking water is common, but technology is now available to allow quicker and more accurate in ovo vaccination of embryos at 18 days of incubation. In this study ΔgG-ILTV was delivered to chicken embryos at three different doses (10(2), 10(3) and 10(4) plaque forming units per egg) using manual in ovo vaccination. At 20 days after hatching, birds were challenged intra-tracheally with wild type ILTV and protection was measured. In ovo vaccination was shown to be safe, as there were no developmental differences between birds from hatching up to 20 days of age, as measured by weight gain. The highest dose of vaccine was the most efficacious, resulting in a weight gain not significantly different from unvaccinated/unchallenged birds seven days after challenge. In contrast, birds vaccinated with the lowest dose showed weight gains not significantly different from unvaccinated/challenged birds. Gross pathology and histopathology of the trachea reflected these observations, with birds vaccinated with the highest dose having less severe lesions. However, qPCR results suggested the vaccine did not prevent the challenge virus replicating in the trachea. This study is the first to assess in ovo delivery of a live attenuated ILTV vaccine and shows that in ovo vaccination with ΔgG-ILTV can be both safe and efficacious.
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.VACCINE.2018.08.012
Abstract: Recombination is closely linked with virus replication and is an important mechanism that contributes to genome ersification and evolution in alphaherpesviruses. Infectious laryngotracheitis (ILTV Gallid alphaherpesvirus 1) is an alphaherpesvirus that causes respiratory disease in poultry. In the past, natural (field) recombination events between different strains of ILTV generated virulent recombinant viruses that have caused severe disease and economic loss in poultry industries. In this study, chickens were vaccinated with attenuated ILTV vaccines to examine the effect of vaccination on viral recombination and ersity following subsequent co-inoculation with two field strains of ILTV. Two of the vaccines (SA2 and A20) prevented ILTV replication in the trachea after challenge, but the level of viral replication after co-infection in birds that received the Serva ILTV vaccine strain did not differ from that of the mock-vaccinated (control) birds. Even though the levels of viral replication were similar in the two groups, the number of recombinant progeny viruses and the level of viral ersity were significantly lower in the Serva-vaccinated birds than in mock-vaccinated birds. In both the mock-vaccinated and Serva-vaccinated groups, a high proportion of recombinant viruses were detected in naïve in-contact chickens that were housed with the co-inoculated birds. Our results indicate that vaccination can limit the number and ersity of recombinant progeny viruses in a manner that is independent of the level of virus replication. It is possible that immune responses induced by vaccination can select for virus genotypes that replicate well under the pressure of the host immune response.
Publisher: Wildlife Disease Association
Date: 2013
DOI: 10.7589/2012-01-027
Abstract: We isolated a macropodid herpesvirus from a free-ranging eastern grey kangaroo (Macropus giganteous) displaying clinical signs of respiratory disease and possibly neurologic disease. Sequence analysis of the herpesvirus glycoprotein G (gG) and glycoprotein B (gB) genes revealed that the virus was an alphaherpesvirus most closely related to macropodid herpesvirus 2 (MaHV-2) with 82.7% gG and 94.6% gB amino acid sequence identity. Serologic analyses showed similar cross-neutralization patterns to those of MaHV-2. The two viruses had different growth characteristics in cell culture. Most notably, this virus formed significantly larger plaques and extensive syncytia when compared with MaHV-2. No syncytia were observed for MaHV-2. Restriction endonuclease analysis of whole viral genomes demonstrated distinct restriction endonuclease cleavage patterns for all three macropodid herpesviruses. These studies suggest that a distinct macropodid alphaherpesvirus may be capable of infecting and causing disease in eastern grey kangaroos.
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.JIM.2015.10.007
Abstract: Serological studies are often conducted to examine exposure to infectious agents in wildlife populations. However, specific immunological reagents for wildlife species are seldom available and can limit the study of infectious diseases in these animals. This study examined the ability of four commercially available immunoglobulin-binding reagents to bind serum immunoglobulins from 17 species within the Marsupialia and Monotremata. Serum s les were assessed for binding, using immunoblots and ELISAs (Enzyme-linked immunosorbent assays), to three microbially-derived proteins - staphylococcal protein A, streptococcal protein G and peptostreptococcal protein L. Additionally, an anti-kangaroo antibody was included for comparison. The inter- and intra-familial binding patterns of the reagents to serum immunoglobulins varied and evolutionary distance between animal species was not an accurate predictor of the ability of reagents to bind immunoglobulins. Results from this study can be used to inform the selection of appropriate immunological reagents in future serological studies in these clades.
Publisher: American Society for Microbiology
Date: 12-2018
DOI: 10.1128/AEM.01822-18
Abstract: Recombination allows alphaherpesviruses to evolve over time and become more virulent. Historically, characterization of viral vaccines in poultry have mainly focused on limiting clinical disease, rather than limiting virus replication, but such approaches can allow field viruses to persist and evolve in vaccinated populations. In this study, we vaccinated chickens with Gallid alphaherpesvirus 1 vaccines that are commercially available in the United States and then performed coinoculations with two field strains of virus to measure the ability of the vaccines to prevent field strains from replicating and recombining. We found that vaccination reduced viral replication, recombination, and ersity compared to those in unvaccinated chickens, although the extent to which this occurred differed between vaccines. We suggest that characterization of vaccines could include studies to examine the ability of vaccines to reduce viral recombination in order to limit the rise of new virulent field strains due to recombination, especially for those vaccines that are known not to prevent viral replication following challenge.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 13-07-2012
Abstract: Problems can arise when vaccines and wild strains of a chicken herpesvirus recombine.
Publisher: Public Library of Science (PLoS)
Date: 19-07-2018
Publisher: Public Library of Science (PLoS)
Date: 26-03-2018
Publisher: Elsevier BV
Date: 02-2010
DOI: 10.1016/J.VACCINE.2009.11.013
Abstract: Infectious laryngotracheitis virus (ILTV), an alphaherpesvirus, causes severe respiratory disease in poultry. Glycoprotein G (gG) is a virulence factor in ILTV. Recent studies have shown that gG-deficient ILTV is an effective attenuated vaccine however the function of ILTV gG is unknown. This study examined the function and in vivo relevance of ILTV gG. The results showed that ILTV gG binds to chemokines with high affinity and inhibits leukocyte chemotaxis. Specific-pathogen-free (SPF) chickens infected with gG-deficient virus had altered tracheal leukocyte populations and lower serum antibody levels compared with those infected with the parent virus. The findings suggest that the absence of chemokine-binding activity during infection with gG-deficient ILTV results in altered host immune responses.
Publisher: Microbiology Society
Date: 21-10-2022
Abstract: Chlamydia psittaci is an avian pathogen with zoonotic potential. In Australia, C. psittaci has been well reported as a cause of reproductive loss in mares which subsequently have been the source of infection and illness in some in-contact humans. To date, molecular typing studies describe the predominant and clonal C. psittaci sequence type (ST)24 strains in horse, psittacine, and human infections. We sought to assess the clonality between ST24 strains and the emergence of equine ST24 with a comprehensive genomics approach. We used culture-independent probe-based and metagenomic whole-genome sequencing to investigate 13 C . psittaci genomes from horses, psittacines, and a pigeon from Australia. Published genomes of 36 C . psittaci strains were also used to contextualise our Australian dataset and investigate lineage ersity. We utilised a single-nucleotide polymorphism (SNP) based clustering and multi-locus sequence typing (MLST) approach. C. psittaci has four major phylogenetic groups (PG1-4) based on core-genome SNP-based phylogeny. PG1 contained clonal global and Australian equine, psittacine, and human ST24 genomes, with a median pairwise SNP distance of 68 SNPs. PG2, PG3, and PG4 had greater genomic ersity, including erse STs collected from birds, livestock, human, and horse hosts from Europe and North America and a racing pigeon from Australia. We show that the clustering of C. psittaci by MLST was congruent with SNP-based phylogeny. The monophyletic ST24 clade has four major sub-lineages. The genomes of 17 Australian human, equine, and psittacine strains collected between 2008 and 2021 formed the predominant ST24 sub-lineage 1 (emerged circa 1979). Despite a temporal distribution of 13 years, the genomes within sub-lineage 1 had a median pairwise SNP distance of 32 SNPs, suggesting a recent population expansion or potential cross-host transmission. However, two C. psittaci genomes collected in 2015 from Victorian parrots clustered into distinct ST24 sub-lineage 4 (emerged circa 1965) with ovine strain C19/98 from Germany. This work describes a comprehensive phylogenomic characterisation of ST24 and identifies a timeline of potential bird-to-equine spillover events.
Publisher: Informa UK Limited
Date: 02-2012
DOI: 10.1080/03079457.2011.643222
Abstract: Live attenuated vaccines have been extensively used to control infectious laryngotracheitis (ILT). Most vaccines are registered/recommended for use via eye-drop although vaccination via drinking-water is commonly used in the field. Drinking-water vaccination has been associated with non-uniform protection. Bird-to-bird passage of chick-embryo-origin (CEO) ILT vaccines has been shown to result in reversion to virulence. The purpose of the present study was to examine the replication and transmission of a commercial CEO infectious laryngotracheitis virus (ILTV) vaccine strain following drinking-water or eye-drop inoculation. Two groups of 10 specific-pathogen-free chickens were each vaccinated with Serva ILTV vaccine strain either via eye-drop or drinking-water. Groups of four or five unvaccinated birds were placed in contact with vaccinated birds at regular intervals. Tracheal swabs were collected every 4 days from vaccinated and in-contact birds to assess viral replication and transmission using quantitative polymerase chain reaction. Compared with eye-drop-vaccinated birds, drinking-water-vaccinated birds showed delayed viral replication but had detectable viral DNA for a longer period of time. Transmission to chickens exposed by contact on day 0 of the experiments was similar in both groups. Birds exposed to ILTV by contact with eye-drop vaccinated birds on days 4, 8, 12 and 16 of the experiment had detectable ILTV for up to 8 days post exposure. ILTV was not detected in chickens that were exposed by contact with drinking-water vaccinated birds on day 12 of the experiment or later. Results from this study provide valuable practical information for the use of ILT vaccine.
Publisher: Informa UK Limited
Date: 16-01-2008
DOI: 10.1080/03079450701802214
Abstract: Infectious laryngotracheitis virus (ILTV), an alphaherpesvirus, causes respiratory disease in chickens and is commonly controlled by vaccination with conventionally attenuated virus strains. These vaccines have limitations due to residual pathogenicity and reversion to virulence. To avoid these problems and to better control disease, attention has recently turned towards developing a novel vaccine strain that lacks virulence gene(s). Glycoprotein G (gG) is a virulence factor in ILTV. A gG-deficient strain of ILTV has been shown to be less pathogenic than currently available vaccine strains following intratracheal inoculation of specific pathogen free chickens. Intratracheal inoculation of gG-deficient ILTV has also been shown to induce protection against disease following challenge with virulent virus. Intratracheal inoculation, however, is not suitable for large-scale vaccination of commercial poultry flocks. In this study, inoculation of gG-deficient ILTV via eye-drop, drinking water and aerosol were investigated. Aerosol inoculation resulted in undesirably low levels of safety and protective efficacy. Inoculation via eye-drop and drinking water was safe, and the levels of protective efficacy were comparable with intratracheal inoculation. Thus, gG-deficient ILTV appears to have potential for use in large-scale poultry vaccination programmes when administered via eye-drop or in drinking water.
Publisher: Informa UK Limited
Date: 04-2012
DOI: 10.1080/03079457.2012.660132
Abstract: Infectious laryngotracheitis (ILT) is an acute infectious viral disease that affects chickens, causing respiratory disease, loss of production and mortality in severe cases. Biosecurity measures and administration of attenuated viral vaccine strains are commonly used to prevent ILT. It is notable that most recent ILT outbreaks affecting the intensive poultry industry have been caused by vaccine-related virus strains. The purpose of this study was to characterize and compare viral replication and transmission patterns of two attenuated chicken embryo origin ILT vaccines delivered via the drinking water. Two groups of specific pathogen free chickens were each inoculated with SA-2 ILT or Serva ILT vaccine strains. Unvaccinated birds were then placed in contact with vaccinated birds at regular intervals. Tracheal swabs were collected every 4 days over a period of 60 days and examined for the presence and amount of virus using a quantitative polymerase chain reaction. A rapid increase in viral genome copy numbers was observed shortly after inoculation with SA-2 ILT virus. In contrast, a comparatively delayed virus replication was observed after vaccination with Serva ILT virus. Transmission to in-contact birds occurred soon after exposure to Serva ILT virus but only several days after exposure to SA-2 ILT virus. Results from this study demonstrate in vivo differences between ILT vaccine strains in virus replication and transmission patterns.
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.VETMIC.2013.12.007
Abstract: A single nucleotide polymorphism (SNP) has been previously associated with EHV-1 neurological disease in several countries around the world. This disease is very uncommon in Australia and little information is available about the presence of this SNP in Australian EHV-1 isolates. The ORF30 sequence of 66 Australian EHV-1 isolates was determined and the genotype was compared to the disease manifestation of the case from which the virus was isolated. Of the 66 isolates, 61 were from cases of abortion and 5 were cases associated with equine herpesvirus myeloencephalopathy (EHM). There was no association between pathotype and genotype in these isolates. In total, 64 of the 66 isolates encoded N752, including 4 isolates from EHM cases. The ORF30 sequence was also determined for 14 EHV-4 isolates, including 2 isolates from confirmed EHV-4 abortion cases. All 14 EHV-4 isolates had aspartic acid at the position equivalent to EHV-1 AA752. Aspartic acid was also confirmed in this position for the single isolate of AHV-3 sequenced in this study. The nucleotide sequence of ORF68 was also determined and showed considerable genetic heterogeneity in the EHV-1 isolates, however, this ORF was highly conserved among the 14 EHV-4 isolates sequenced, with only one SNP identified among 7 isolates. These results confirm that the EHV1 ORF30 N752 is unique and that the D752 sequence is most likely to be the true parent strain of this virus. We suggest that the abortigenic form of EHV-1 should be considered to be the more recently emerged mutant.
Publisher: Elsevier BV
Date: 08-2016
DOI: 10.1016/J.COVIRO.2016.06.007
Abstract: Spillover of viruses from farmed poultry into wild birds is a relatively new area of study at the livestock-wildlife interface. These transmission events can threaten the health of wild birds. There is growing evidence of transmission of vaccine viruses from poultry to wild birds, including attenuated vaccine strains of Newcastle disease virus and infectious bronchitis virus, and also spread of virulent viruses that may have evolved under the pressure of vaccine use, such as Marek's disease virus. Viral contaminants of poultry vaccines, including reticuloendotheliosis virus, may also be transmitted to wild birds and result in disease. New, vectored vaccines are less likely to directly spread to wild birds but this risk may rise as a result of recombination.
Publisher: Wildlife Disease Association
Date: 04-2014
DOI: 10.7589/2013-08-202
Abstract: Sixty (19 male, 41 female) free-ranging adult eastern bettongs (Bettongia gaimardi) were captured in Tasmania and translocated to the Australian Capital Territory between July 2011 and September 2012 for reintroduction into fenced, predator-proof reserves. The bettongs were anesthetized for physical examination and screened for selected diseases during translocation. Reference ranges for hematologic and biochemical parameters were determined. Two bettongs had detectable antibodies to the alphaherpesviruses macropodid herpesvirus 1 and macropodid herpesvirus 2 by serum neutralization assay. A novel gammaherpesvirus was detected, via PCR, from pooled swabs collected from the nasal, conjunctival, and urogenital tract mucosa of four other bettongs. Sera from 59 bettongs were negative for antibodies to Toxoplasma gondii as assessed by both the modified agglutination test and the direct agglutination test (n = 53) or by the modified agglutination test only (n = 6). Rectal swabs from 14 bettongs were submitted for bacterial culture and all were negative for Salmonella serovars. Ectoparasites identified on the bettongs included fleas (Pygiopsylla zethi, Stephanocircus harrisoni), a louse (Paraheterodoxous sp.), mites (Guntheria cf. pertinax, Haemolaelaps hatteni, a suspected protonymph of Thadeua sp., Cytostethum tasmaniense, Cytostethum intermedium, Cytostethum thetis, Cytostethum wallabia), and ticks (Ixodes cornuatus, Ixodes trichosuri, Ixodes tasmani). An intraerythrocytic organism morphologically consistent with a Theileria species was identified in blood smears from four bettongs. These data provide baseline health and disease information for free-ranging eastern bettongs that can be used for the conservation management of both the source and translocated populations.
Publisher: MDPI AG
Date: 28-07-2023
DOI: 10.3390/ANI13152443
Abstract: Chlamydia psittaci is an important zoonotic pathogen. Although primarily a pathogen of birds, from which infection can spillover into humans and other mammalian hosts, the importance of C. psittaci as a cause of equine reproductive loss and the risk of infection to humans in contact with infected horses are increasingly being recognised in Australia and elsewhere. Despite the risks to both human and equine health, C. psittaci infection in horses is incompletely understood. This study aimed to update and summarise cases of equine psittacosis in Australia in the period 2018–2022, thus addressing a knowledge gap relating to recent cases in this country. These cases were identified from the examination of records held by state and federal veterinary authorities and from a review of published cases. A total of 31 cases were identified. Spatial and temporal trends were identified, with cases being more prevalent in winter and spring and geographically restricted to Victoria and New South Wales. The results show that cases of equine reproductive loss due to C. psittaci are consistent and ongoing and demonstrate the importance of routinely considering C. psittaci in diagnostic investigations. The need for ongoing study to better understand this important zoonotic pathogen is evident.
Publisher: Elsevier BV
Date: 08-2022
Publisher: Wildlife Disease Association
Date: 04-2014
DOI: 10.7589/2013-07-165
Abstract: We detected herpesvirus infection in a male yellow-footed antechinus (Antechinus flavipes) and male agile antechinus (Antechinus agilis) during the period of postmating male antechinus immunosuppression and mortality. Histopathologic examination of tissues revealed lesions consistent with herpesvirus infection in the prostate of both animals. Herpesvirus virions were observed by transmission electron microscopy in the prostate tissue collected from the male yellow-footed antechinus. Herpesvirus DNA was detected in prostate, liver, lung, kidney, spleen, and ocular/nasal tissues using a pan-herpesvirus PCR targeting the viral DNA polymerase. Nucleotide sequencing identified a novel herpesvirus from the Gammaherpesvirinae subfamily that we have tentatively designated dasyurid herpesvirus 1 (DaHV-1).
Publisher: Elsevier BV
Date: 05-2018
Abstract: To better understand factors influencing infectious agent dispersal within a livestock population information is needed on the nature and frequency of contacts between farm enterprises. This study uses social network analysis to describe the contact network within a vertically integrated broiler poultry enterprise to identify the potential horizontal and vertical transmission pathways for Salmonella spp. Nodes (farms, sheds, production facilities) were identified and the daily movement of commodities (eggs, birds, feed, litter) and people between nodes were extracted from routinely kept farm records. Three time periods were examined in detail, 1- and 8- and 17-weeks of the production cycle and contact networks were described for all movements, and by commodity and production type. All nodes were linked by at least one movement during the study period but network density was low indicating that all potential pathways between nodes did not exist. Salmonella spp. transmission via vertical or horizontal pathways can only occur along directed pathways when those pathways are present. Only two locations (breeder or feed nodes) were identified where the transmission of a single Salmonella spp. clone could theoretically percolate through the network to the broiler or processing nodes. Only the feed transmission pathway directly connected all parts of the network.
Publisher: The Royal Society
Date: 07-09-2020
Abstract: During the summer of 2018, a widespread drought developed over Northern and Central Europe. The increase in temperature and the reduction of soil moisture have influenced carbon dioxide (CO 2 ) exchange between the atmosphere and terrestrial ecosystems in various ways, such as a reduction of photosynthesis, changes in ecosystem respiration, or allowing more frequent fires. In this study, we characterize the resulting perturbation of the atmospheric CO 2 seasonal cycles. 2018 has a good coverage of European regions affected by drought, allowing the investigation of how ecosystem flux anomalies impacted spatial CO 2 gradients between stations. This density of stations is unprecedented compared to previous drought events in 2003 and 2015, particularly thanks to the deployment of the Integrated Carbon Observation System (ICOS) network of atmospheric greenhouse gas monitoring stations in recent years. Seasonal CO 2 cycles from 48 European stations were available for 2017 and 2018. Earlier data were retrieved for comparison from international databases or national networks. Here, we show that the usual summer minimum in CO 2 due to the surface carbon uptake was reduced by 1.4 ppm in 2018 for the 10 stations located in the area most affected by the temperature anomaly, mostly in Northern Europe. Notwithstanding, the CO 2 transition phases before and after July were slower in 2018 compared to 2017, suggesting an extension of the growing season, with either continued CO 2 uptake by photosynthesis and/or a reduction in respiration driven by the depletion of substrate for respiration inherited from the previous months due to the drought. For stations with sufficiently long time series, the CO 2 anomaly observed in 2018 was compared to previous European droughts in 2003 and 2015. Considering the areas most affected by the temperature anomalies, we found a higher CO 2 anomaly in 2003 (+3 ppm averaged over 4 sites), and a smaller anomaly in 2015 (+1 ppm averaged over 11 sites) compared to 2018. This article is part of the theme issue ‘Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.
Publisher: Elsevier BV
Date: 2019
Publisher: Cold Spring Harbor Laboratory
Date: 03-10-2023
Publisher: American Society for Microbiology
Date: 06-2016
DOI: 10.1128/CVI.00724-15
Abstract: Although many studies have reported the indirect immunofluorescence assay (IFA) to be more sensitive in detection of antibodies to Coxiella burnetii than the complement fixation test (CFT), the diagnostic sensitivity (DSe) and diagnostic specificity (DSp) of the assay have not been previously established for use in ruminants. This study aimed to validate the IFA by describing the optimization, selection of cutoff titers, repeatability, and reliability as well as the DSe and DSp of the assay. Bayesian latent class analysis was used to estimate diagnostic specifications in comparison with the CFT and the enzyme-linked immunosorbent assay (ELISA). The optimal cutoff dilution for screening for IgG and IgM antibodies in goat serum using the IFA was estimated to be 1:160. The IFA had good repeatability ( .9% for IgG, .0% for IgM), and there was almost perfect agreement (Cohen's kappa 0.80 for IgG) between the readings reported by two technicians for s les tested for IgG antibodies. The IFA had a higher DSe (94.8% 95% confidence interval [CI], 80.3, 99.6) for the detection of IgG antibodies against C. burnetii than the ELISA (70.1% 95% CI, 52.7, 91.0) and the CFT (29.8% 95% CI, 17.0, 44.8). All three tests were highly specific for goat IgG antibodies. The IFA also had a higher DSe (88.8% 95% CI, 58.2, 99.5) for detection of IgM antibodies than the ELISA (71.7% 95% CI, 46.3, 92.8). These results underscore the better suitability of the IFA than of the CFT and ELISA for detection of IgG and IgM antibodies in goat serum and possibly in serum from other ruminants.
Publisher: Springer Science and Business Media LLC
Date: 22-01-2016
Publisher: Microbiology Society
Date: 10-2006
Abstract: Infectious laryngotracheitis virus (ILTV Gallid herpesvirus 1 ) is an alphaherpesvirus that causes acute respiratory disease in chickens. The role of glycoprotein G (gG) in vitro has been investigated in a number of alphaherpesviruses, but the relevance of gG in vivo in the pathogenicity of ILTV or in other alphaherpesviruses is unknown. In this study, gG-deficient mutants of ILTV were generated and inoculated into specific-pathogen-free chickens to assess the role of gG in pathogenicity. In chickens, gG-deficient ILTV reached a similar titre to wild-type (wt) ILTV but was significantly attenuated with respect to induction of clinical signs, effect on weight gain and bird mortality. In addition, an increased tracheal mucosal thickness, reflecting increased inflammatory cell infiltration at the site of infection, was detected in birds inoculated with gG-deficient ILTV compared with birds inoculated with wt ILTV. The reinsertion of gG into gG-deficient ILTV restored the in vivo phenotype of the mutant to that of wt ILTV. Quantitative PCR analysis of the expression of the genes adjacent to gG demonstrated that they were not affected by the deletion of gG and investigations in vitro confirmed that the phenotype of gG-deficient ILTV was consistent with unaltered expression of these adjacent genes. This is the first reported study to demonstrate definitively that gG is a virulence factor in ILTV and that deletion of gG from this alphaherpesvirus genome causes marked attenuation of the virus in its natural host.
Publisher: Public Library of Science (PLoS)
Date: 06-12-2018
Publisher: Elsevier BV
Date: 08-2011
DOI: 10.1016/J.VACCINE.2011.06.002
Abstract: Infectious laryngotracheitis virus (ILTV) is an alphaherpesvirus that causes acute respiratory disease in chickens worldwide. The virus is horizontally transmitted and causes large outbreaks of disease. Recent studies have shown that a glycoprotein G deficient candidate vaccine strain of ILTV (ΔgG ILTV) is safe and protects birds from disease following challenge with virulent virus. This study examined the transmission dynamics of this candidate vaccine and of ILTV in field and experimental settings. The reproduction ratio (R₀, average number of secondary infectious cases from a typical infectious case) was calculated from the growth rate of disease epidemics in broiler flocks. Assuming a latent period of 2 days and an infectious period of 4 days R₀ was estimated to be 2.43 (95% CI 2.25-2.69). In experimental settings the transmission characteristics of ΔgG ILTV were similar to those of wildtype virus, and importantly ΔgG ILTV remained safe following one in vivo passage and subsequent infection via contact-exposure. There was minimal transmission of wildtype virus in vaccinated birds. The findings from this study further demonstrate the suitability of ΔgG ILTV for use as a live attenuated vaccine. Knowledge of the basic reproduction ratio of ILTV will be valuable for future studies that aim to improve disease control using vaccination programs.
Publisher: Public Library of Science (PLoS)
Date: 23-03-2018
Publisher: Public Library of Science (PLoS)
Date: 29-07-2015
Publisher: Springer Science and Business Media LLC
Date: 20-03-2009
Publisher: Public Library of Science (PLoS)
Date: 26-05-2020
Publisher: American Society of Parasitologists
Date: 02-2018
DOI: 10.1645/17-111
Abstract: A novel coccidian species was discovered in the prostate of an Antechinus flavipes (yellow-footed antechinus) in South Australia during the period of postmating male antechinus immunosuppression and mortality. This novel coccidian is unusual because it develops extraintestinally and sporulates endogenously within the prostate gland of its mammalian host. Histological examination of prostatic tissue revealed dense aggregations of spherical and thin-walled tetrasporocystic, dizoic, sporulated coccidian oocysts within tubular lumina, with unsporulated oocysts and gamogonic stages within the cytoplasm of glandular epithelial cells. This coccidian was observed occurring concurrently with dasyurid gammaherpesvirus 1 infection of the antechinus' prostate. Eimeria-specific 18S small-subunit ribosomal (r)DNA polymerase chain reaction lification was used to obtain a partial 18S rDNA nucleotide sequence from the antechinus coccidian. Bayesian phylogenetic analysis based on 18S rDNA gene sequences revealed that the novel coccidian clusters with reptile-host coccidians, forming an ancestral basal lineage of the eimeriid clade. The species has been named Eimeria taggarti n. sp. on the basis of both sporulated oocyst morphology and molecular characterization. It is suspected that E. taggarti is sexually transmitted via excretion of sporulated oocysts or free sporocysts with prostatic secretions in semen.
Publisher: American Society for Microbiology
Date: 12-2017
DOI: 10.1128/AEM.01532-17
Abstract: Recombination is a feature of many alphaherpesviruses that infect people and animals. Infectious laryngotracheitis virus (ILTV Gallid alphaherpesvirus 1 ) causes respiratory disease in chickens, resulting in significant production losses in poultry industries worldwide. Natural (field) ILTV recombination is widespread, particularly recombination between attenuated ILTV vaccine strains to create virulent viruses. These virulent recombinants have had a major impact on animal health. Recently, the development of a single nucleotide polymorphism (SNP) genotyping assay for ILTV has helped to understand ILTV recombination in laboratory settings. In this study, we applied this SNP genotyping assay to further examine ILTV recombination in the natural host. Following coinoculation of specific-pathogen-free chickens, we examined the resultant progeny for evidence of viral recombination and characterized the ersity of the recombinants over time. The results showed that ILTV replication and recombination are closely related and that the recombinant viral progeny are most erse 4 days after coinoculation, which is the peak of viral replication. Further, the locations of recombination breakpoints in a selection of the recombinant progeny, and in field isolates of ILTV from different geographical regions, were examined following full-genome sequencing and used to identify recombination hot spots in the ILTV genome. IMPORTANCE Alphaherpesviruses are common causes of disease in people and animals. Recombination enables genome ersification in many different species of alphaherpesviruses, which can lead to the evolution of higher levels of viral virulence. Using the alphaherpesvirus infectious laryngotracheitis virus (ILTV), we performed coinfections in the natural host (chickens) to demonstrate high levels of virus recombination. Higher levels of ersity in the recombinant progeny coincided with the highest levels of virus replication. In the recombinant progeny, and in field isolates, recombination occurred at greater frequency in recombination hot spot regions of the virus genome. Our results suggest that control measures that aim to limit viral replication could offer the potential to limit virus recombination and thus the evolution of virulence. The development and use of vaccines that are focused on limiting virus replication, rather than vaccines that are focused more on limiting clinical disease, may be indicated in order to better control disease.
Publisher: Informa UK Limited
Date: 06-2011
DOI: 10.1080/03079457.2011.553582
Abstract: Infectious laryngotracheitis is an acute viral respiratory disease of chickens with a worldwide distribution. Sensitive detection of the causative herpesvirus is particularly important because it can persist in the host at a very low copy number and be transmitted to other birds. Quantification of viral genome copy number is also useful for clinical investigations and experimental studies. In the study presented here, a quantitative polymerase chain reaction (qPCR) assay was developed using SYBR Green chemistry and the viral gene UL15a to detect and quantify infectious laryngotracheitis virus (ILTV) in ILTV-inoculated chicken embryos or naturally infected birds. The specificity of the assay was confirmed using a panel of viral and bacterial pathogens of poultry. The sensitivity of the assay was compared with two conventional PCR assays, virus titration and an antigen-detecting enzyme-linked immunosorbent assay. The qPCR developed in this study was highly sensitive and specific, and has potential for quantification of ILTV in tissues from naturally and experimentally infected birds and embryos.
Publisher: Microbiology Society
Date: 07-2017
DOI: 10.1099/JMM.0.000516
Abstract: Beak and feather disease virus (BFDV) is a circovirus and the cause of psittacine beak and feather disease (PBFD). This disease is characterized by feather and beak deformities and is a recognized threat to endangered Psittaciformes (parrots and cockatoos). The role that non-psittacine birds may play as reservoirs of infection is unclear. This study aimed to begin addressing this gap in our knowledge of PBFD. Liver s les were collected from birds presented to the Australian Wildlife Health Centre at Zoos Victoria's Healesville Sanctuary for veterinary care between December 2014 and December 2015, and tested for BFDV DNA using polymerase chain reaction coupled with sequencing and phylogenetic analyses.Results/Key findings. Overall BFDV was detected in 38.1 % of 210 birds. BFDV was detected at high prevalence (56.2 %) in psittacine birds, in the majority of cases without any observed clinical signs of PBFD. We also found that BFDV was more common in non-psittacine species than previously recognized, with BFDV detected at 20.0 % prevalence in the non-psittacine birds tested, including species with no clear ecological association with psittacines, and without showing any detectable clinical signs of BFDV infection. Further research to determine the infectivity and transmissibility of BFDV in non-psittacine species is indicated. Until such work is undertaken the findings from this study suggest that every bird should be considered a potential carrier of BFDV, regardless of species and clinical presentation. Veterinary clinics and wildlife rehabilitation facilities caring for birds that are susceptible to PBFD should reconsider biosecurity protocols aimed at controlling BFDV.
Publisher: Springer Science and Business Media LLC
Date: 15-09-2017
Publisher: Wildlife Disease Association
Date: 04-2015
DOI: 10.7589/2014-07-176
Abstract: Chlamydia infection is known to impact the health of koalas (Phascolarctos cinereus) in New South Wales (NSW) and Queensland, but the clinical significance of Chlamydia infections in Victorian koalas is not well described. We examined the prevalence of Chlamydia infection and assessed associated health parameters in two Victorian koala populations known to be Chlamydia positive. The same testing regimen was applied to a third Victorian population in which Chlamydia had not been detected. We examined 288 koalas and collected s les from the urogenital sinus and conjunctival sacs. Detection and differentiation of Chlamydia species utilized real-time PCR and high-resolution melting curve analysis. Chlamydia pecorum was detected in two populations (prevalences: 25% and 41%, respectively) but only from urogenital sinus swabs. Chlamydia was not detected in the third population. Chlamydia pneumoniae was not detected. Chlamydia pecorum infection was positively associated with wet bottom (indicating chronic urinary tract disease) in one Chlamydia-positive population and with abnormal urogenital ultrasound findings in the other Chlamydia-positive population. The prevalence of wet bottom was similar in all populations (including the Chlamydia-free population), suggesting there is another significant cause (or causes) of wet bottom in Victorian koalas. Ocular disease was not observed. This is the largest study of Chlamydia infection in Victorian koalas, and the results suggest the potential for epidemiologic differences related to Chlamydia infections between Victorian koalas and koalas in Queensland and NSW and also between geographically distinct Victorian populations. Further studies to investigate the genotypes of C. pecorum present in Victorian koalas and to identify additional causes of wet bottom in koalas are indicated.
Publisher: Wildlife Disease Association
Date: 28-04-2016
DOI: 10.7589/2015-10-276
Publisher: Springer Science and Business Media LLC
Date: 02-09-2016
Publisher: Wiley
Date: 25-11-2022
DOI: 10.1111/JVIM.16587
Abstract: Inhibition of antiapoptotic B-cell lymphoma 2 (BCL2) proteins by small molecule Bcl-2 homology 3 (BH3) mimetics causes rapid induction of apoptosis of human hematological cancers in vitro and in vivo. Assess in vitro sensitivity of non-neoplastic lymphocytes and primary hematological cancer cells from dogs to venetoclax (VEN) or the dual BCL2/ B-cell lymphoma-extra-large (BCLxL) inhibitor, navitoclax (NAV), and evaluate the association between BCL2 protein expression and VEN sensitivity. Nine client-owned dogs without cancer and 18 client-owned dogs with hematological cancer. Prospective, nonrandomized noncontrolled study. Lymphocytes isolated from peripheral blood, lymph node, or bone marrow from dogs were incubated with BH3 mimetics for 24 hours. Viable cells were counted using flow cytometry and half maximal effective concentration (EC Nodal B and T lymphocytes were more sensitive to VEN than circulating lymphocytes (P = .02). Neoplastic T lymphocytes were sensitive to VEN (mean EC Neoplastic canine T lymphocytes are sensitive to VEN in vitro. Quantification of BCL2 protein alone is insufficient to predict sensitivity to VEN.
Publisher: Microbiology Society
Date: 02-2021
DOI: 10.1099/JMM.0.001284
Abstract: Introduction. Chlamydia psittaci is primarily a pathogen of birds but can also cause disease in other species. Equine reproductive loss caused by C. psittaci has recently been identified in Australia where cases of human disease were also reported in in iduals exposed to foetal membranes from an ill neonatal foal in New South Wales. Hypothesis/Gap Statement. The prevalence of C. psittaci in association with equine reproductive over time and in different regions of Australia is not known. Aim. This study was conducted to detect C. psittaci in equine abortion cases in Australia using archived s les spanning 25 years. Methodology. We tested for C. psittaci in 600 equine abortion cases reported in Australia between 1994 to 2019 using a Chlamydiaceae real-time quantitative PCR assay targeting the 16S rRNA gene followed by high-resolution melt curve analysis. Genotyping and phylogenetic analysis was performed on positive s les. Results. The overall prevalence of C. psittaci in material from equine abortion cases was 6.5 %. C. psittaci -positive cases were detected in most years that were represented in this study and occurred in Victoria (prevalence of 7.6 %), New South Wales (prevalence of 3.9 %) and South Australia (prevalence of 15.4 %). Genotyping and phylogenetic analysis showed that the C. psittaci detected in the equine abortion cases clustered with the parrot-associated 6BC clade (genotype A/ST24), indicating that infection of horses may be due to spillover from native Australian parrots. Conclusion. This work suggests that C. psittaci has been a significant agent of equine abortion in Australia for several decades and underscores the importance of taking appropriate protective measures to avoid infection when handling equine aborted material.
Publisher: Public Library of Science (PLoS)
Date: 02-2013
Publisher: Springer Science and Business Media LLC
Date: 10-2016
Publisher: Springer Science and Business Media LLC
Date: 19-04-2011
Publisher: Public Library of Science (PLoS)
Date: 28-03-2019
Publisher: Springer Science and Business Media LLC
Date: 13-02-2017
DOI: 10.1007/S00705-017-3266-8
Abstract: Infectious laryngotracheitis virus (ILTV) encodes several unique genes, including a pair of unique nuclear proteins UL0 and UL[-1] that are expressed during replication in cell culture. Although the UL0 gene has been shown to be dispensable for replication, the role of UL[-1] has not been elucidated. In this study a deletion mutant of ILTV lacking the UL[-1] gene was constructed using homologous recombination. The coding sequences of the gene were replaced with the gene for enhanced green fluorescent protein and the cytomegalovirus major immediate early promoter element. The progeny virus carrying the reporter gene was readily identified using fluorescent microscopy, but was unable to propagate in the permissive cells in the absence of wild type ILTV. Even after plaque purification and fluorescent associated cell sorting the recombinant virus deficient in UL[-1] gene could not be successfully isolated. Our findings suggest that the UL[-1] gene has an important role in ILTV replication.
Publisher: American Association of Avian Pathologists (AAAP)
Date: 25-10-2013
Publisher: Microbiology Society
Date: 03-2016
DOI: 10.1099/JGV.0.000378
Publisher: Public Library of Science (PLoS)
Date: 28-03-2017
Publisher: MDPI AG
Date: 11-08-2021
DOI: 10.3390/PATHOGENS10081015
Abstract: Chlamydia psittaci is traditionally regarded as a globally distributed avian pathogen that can cause zoonotic spill-over. Molecular research has identified an extended global host range and significant genetic ersity. However, Australia has reported a reduced host range (avian, horse, and human) with a dominance of clonal strains, denoted ST24. To better understand the widespread of this strain type in Australia, multilocus sequence typing (MLST) and ompA genotyping were applied on s les from a range of hosts (avian, equine, marsupial, and bovine) from Australia. MLST confirms that clonal ST24 strains dominate infections of Australian psittacine and equine hosts (82/88 93.18%). However, this study also found novel hosts (Australian white ibis, King parrots, racing pigeon, bovine, and a wallaby) and demonstrated that strain ersity does exist in Australia. The discovery of a C. psittaci novel strain (ST306) in a novel host, the Western brush wallaby, is the first detection in a marsupial. Analysis of the results of this study applied a multidisciplinary approach regarding Chlamydia infections, equine infectious disease, ecology, and One Health. Recommendations include an update for the descriptive framework of C. psittaci disease and cell biology work to inform pathogenicity and complement molecular epidemiology.
Publisher: Informa UK Limited
Date: 06-2013
DOI: 10.1080/03079457.2013.780649
Abstract: Infectious laryngotracheitis virus (ILTV) causes severe respiratory disease in poultry throughout the world. Recently the role of glycoprotein G (gG) in ILTV pathogenesis has been investigated and it has been shown to have chemokine-binding activity. An ILTV vaccine candidate deficient in gG has been developed and the deletion has been shown to alter the host's immune response to the virus. To understand the effect of the gG gene on transcription of other viral genes, the global expression profile of 72 ILTV genes in gG-deleted and wild-type ILTVs were investigated both in vivo and in vitro using quantitative reverse transcription-polymerase chain reaction. Several genes were differentially expressed in the different viruses in LMH cell cultures or in the tracheas of infected birds, and the expression of a number of genes, including ICP27, gC, gJ, Ul7 and UL40, differed significantly both in vivo and in vitro, suggesting that they had direct or indirect roles in virulence. This study has provided insights into the interactions between gG and other ILTV genes that may have a role in virulence.
Start Date: 12-2020
End Date: 12-2024
Amount: $717,363.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2014
End Date: 11-2017
Amount: $370,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2013
End Date: 12-2016
Amount: $330,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2009
End Date: 04-2013
Amount: $278,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 12-2023
End Date: 12-2026
Amount: $377,577.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2015
End Date: 12-2019
Amount: $772,104.00
Funder: Australian Research Council
View Funded ActivityStart Date: 05-2018
End Date: 10-2023
Amount: $348,214.00
Funder: Australian Research Council
View Funded Activity