Veterinary Biosciences - Research Publications
Now showing items 1-12 of 1011
"Begging the Question"-Does Toxocara Infection/Exposure Associate with Multiple Sclerosis-Risk?
Although the cause of multiple sclerosis (MS) is unclear, infectious agents, including some parasitic roundworms (nematodes), have been proposed as possible risk factors or contributors. Here, we conducted a systematic review and meta-analysis of published observational studies to evaluate whether there is a possible association between infection with, or exposure to, one or more members of the genus Toxocara (phylum Nematoda; superfamily Ascaridoidea) and MS. We undertook a search of public literature databases to identify relevant studies and then used a random-effects meta-analysis model to generate the pooled odds ratio (OR) and 95% confidence intervals (CIs). This search identified six of a total of 1371 articles that were relevant to the topic; these published studies involved totals of 473 MS patients and 647 control subjects. Anti-Toxocara IgG serum antibodies were detected in 62 MS patients and 37 controls, resulting in respective seroprevalences of 13.1% (95% CI: 8.2–20.3) and 4.8% (95% CI: 2.5–9.2), indicating an association (pooled OR, 3.01; 95% CI: 1.46–6.21). Because of the publication bias identified (six eligible studies), well-designed and -controlled studies are required in the future to rigorously test the hypothesis that Toxocara infection/exposure has an association with MS.
"Feelings and Fitness" Not "Feelings or Fitness"-The Raison d'être of Conservation Welfare, Which Aligns Conservation and Animal Welfare Objectives.
(Frontiers Media SA, 2018)
Increasingly, human activities, including those aimed at conserving species and ecosystems (conservation activities) influence not only the survival and fitness but also the welfare of wild animals. Animal welfare relates to how an animal is experiencing its life and encompasses both its physical and mental states. While conservation biology and animal welfare science are both multi-disciplinary fields that use scientific methods to address concerns about animals, their focus and objectives sometimes appear to conflict. However, activities impacting detrimentally on the welfare of individual animals also hamper achievement of some conservation goals, and societal acceptance is imperative to the continuation of conservation activities. Thus, the best outcomes for both disciplines will be achieved through collaboration and knowledge-sharing. Despite this recognition, cross-disciplinary information-sharing and collaborative research and practice in conservation are still rare, with the exception of the zoo context. This paper summarizes key points developed by a group of conservation and animal welfare scientists discussing scientific assessment of wild animal welfare and barriers to progress. The dominant theme emerging was the need for a common language to facilitate cross-disciplinary progress in understanding and safeguarding the welfare of animals of wild species. Current conceptions of welfare implicit in conservation science, based mainly on "fitness" (physical states), need to be aligned with contemporary animal welfare science concepts which emphasize the dynamic integration of "fitness" and "feelings" (mental experiences) to holistically understand animals' welfare states. The way in which animal welfare is characterized influences the way it is evaluated and the emphasis put on different features of welfare, as well as, the importance placed on the outcomes of such evaluations and how that information is used, for example in policy development and decision-making. Salient examples from the New Zealand and Australian context are presented to illustrate. To genuinely progress our understanding and evaluation of wild animal welfare and optimize the aims of both scientific disciplines, conservation and animal welfare scientists should work together to evolve and apply a common understanding of welfare. To facilitate this, we propose the formal development of a new discipline, Conservation Welfare, integrating the expertise of scientists from both fields.
1-Methyl-1H-pyrazole-5-carboxamide Derivatives Exhibit Unexpected Acute Mammalian Toxicity
(AMER CHEMICAL SOC, 2021-01-14)
A series of 1-methyl-1H-pyrazole-5-carboxamides were synthesized as potent inhibitors of the parasitic nematode of sheep, Haemonchus contortus. These compounds did not show overt cytotoxicity to a range of mammalian cell lines under standard in vitro culture conditions, had high selectivity indices, and were progressed to an acute toxicity study in a rodent model. Strikingly, acute toxicity was observed in mice. Experiments measuring cellular respiration showed a dose-dependent inhibition of mitochondrial respiration. Under these conditions, potent cytotoxicity was observed for these compounds in rat hepatocytes suggesting that the potent acute mammalian toxicity of this chemotype is most likely associated with respiratory inhibition. In contrast, parasite toxicity was not correlated to acute toxicity or cytotoxicity in respiring cells. This paper highlights the importance of identifying an appropriate in vitro predictor of in vivo toxicity early on in the drug discovery pipeline, in particular assessment for in vitro mitochondrial toxicity.
(International Union of Crystallography (IUCr), 2012-07-01)
In the title compound, C(8)H(9)BrN(2)O, the 1-bromo-4-methyl-benzene group and the formic hydrazide moiety [r.m.s. deviations of 0.0129 and 0.0038 Å] are oriented at a dihedral angle of 80.66 (11)°. In the crystal, mol-ecules are linked via strong N-H⋯O hydrogen bonds, leading to the formation of chains in the  direction. These chains are linked via weaker N-H⋯N and N-H⋯O hydrogen bonds, with R(2) (2)(7) and R(3) (2)(7) ring motifs, forming a two-dimensional network parallel to (001).
(International Union of Crystallography (IUCr), 2012-04-01)
The asymmetric unit of the the title compound, C(7)H(7)ClN(2)O, contains two mol-ecules in which the chloro-phenyl and the formic hydrazide units are almost planar (r.m.s. deviations of 0.0081 and 0.0100 Å, respectively, in one mol-ecule and 0.0069 and 0.0150 Å in the other) and are oriented with respect to each other at dihedral angles of 56.8 (2) and 56.9 (2)°. In the crystal, the mol-ecules are consolidated in the form of polymeric chains extending along . R(3) (3)(10) ring motifs exist due to N-H⋯O and N-H⋯N hydrogen bonds.
A 2015 outbreak of Getah virus infection occurring among Japanese racehorses sequentially to an outbreak in 2014 at the same site
(BIOMED CENTRAL LTD, 2016-06-10)
BACKGROUND: As we reported previously, Getah virus infection occurred in horses at the Miho training center of the Japan Racing Association in 2014. This was the first outbreak after a 31-year absence in Japan. Here, we report a recurrent outbreak of Getah virus infection in 2015, sequential to the 2014 one at the same site, and we summarize its epizootiological aspects to estimate the risk of further outbreaks in upcoming years. RESULTS: The outbreak occurred from mid-August to late October 2015, affecting 30 racehorses with a prevalence of 1.5% of the whole population (1992 horses). Twenty-seven (90.0%) of the 30 affected horses were 2-year-olds, and the prevalence in 2-year-olds (27/613 [4.4%]) was significantly higher than that in horses aged 3 years or older (3/1379 [0.2%], P < 0.01). Therefore, the horses newly introduced from other areas at this age were susceptible, whereas most horses aged 3 years or older, which had experienced the previous outbreak in 2014, were resistant. Among the 2-year-olds, the prevalence in horses that had been vaccinated once (10/45 [22.2%]) was significantly higher than that in horses vaccinated twice or more (17/568 [3.0 %], P < 0.01). Horse anti-sera raised against an isolate in 2014 neutralized both the homologous strain and a 2015 isolate at almost the same titers (256 to 512), suggesting that these viruses were antigenically similar. Among horses entering the training center from private surrounding farms in 2015, the seropositivity rate to Getah virus increased gradually (11.8% in August, 21.7% in September, and 34.9% in October). Thus, increased virus exposure due to the regional epizootic probably allowed the virus to spread in the center, similarly to the outbreak in 2014. CONCLUSIONS: The 2015 outbreak was caused by a virus which was antigenically close to the 2014 isolate, affecting mostly 2-year-old susceptible horses under epizootiological circumstances similar to those in 2014. The existence of 2-year-olds introduced from regions free from Getah virus could continue to pose a potential risk of additional outbreaks in upcoming years. Vaccination on private farms and breeding farms would help to minimize the risk of outbreaks.
A 25-year retrospective study of Chlamydia psittaci in association with equine reproductive loss in Australia
(MICROBIOLOGY SOC, 2021-01-01)
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 individuals 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 samples 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 samples.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.
A case-control study to identify risk factors for adult-onset idiopathic megaoesophagus in Australian dogs, 2017-2018
BACKGROUND: Epidemiological investigations were carried out following detection of an outbreak of megaoesophagus in Victorian Police working dogs in early 2018 and an increase in the number of canine megaoesophagus cases reported by companion animal veterinarians in Eastern Australia starting in late 2017. VetCompass Australia data were used to quantify the incidence of canine megaoesophagus for the period January 2012 to February 2018 and a matched case-control study carried out to identify individual animal risk factors for canine megaoesophagus in 2017-2018. RESULTS: There was a 7-fold increase in the incidence rate of canine megaoesophagus from 2014 (0.11 [95% CI 0.02 to 0.58] cases per 100,000 dogs per day) to 2018 (0.82 [95% CI 0.19 to 4.2] cases per 100,000 dogs per day). Since 2013, the incidence of megaoesophagus in Australia has shown a seasonal pattern, with greater numbers of cases diagnosed during the warmer months of the year. In the case-control study, use of Mars Petcare Advance Dermocare as a source of food was 325 (95% CI 64 to 1644) times greater for cases, compared with controls. CONCLUSIONS: Our analyses provide evidence that the feeding of Advance Dermocare was responsible for the majority of cases in the outbreak of megaoesophagus in Eastern Australia in 2017-2018. The increase in the incidence rate of megaoesophagus in Australia since 2014-2015 warrants further investigation.
A chromosome-scale reference genome for Giardia intestinalis WB
(NATURE PUBLISHING GROUP, 2020-02-04)
Giardia intestinalis is a protist causing diarrhea in humans. The first G. intestinalis genome, from the WB isolate, was published more than ten years ago, and has been widely used as the reference genome for Giardia research. However, the genome is fragmented, thus hindering research at the chromosomal level. We re-sequenced the Giardia genome with Pacbio long-read sequencing technology and obtained a new reference genome, which was assembled into near-complete chromosomes with only four internal gaps at long repeats. This new genome is not only more complete but also better annotated at both structural and functional levels, providing more details about gene families, gene organizations and chromosomal structure. This near-complete reference genome will be a valuable resource for the Giardia community and protist research. It also showcases how a fragmented genome can be improved with long-read sequencing technology completed with optical maps.
A cluster-randomised controlled trial comparing school and community-based deworming for soil transmitted helminth control in school-age children: the CoDe-STH trial protocol
BACKGROUND: Current guidelines and targets for soil-transmitted helminth (STH) control focus on school-based deworming for school-age children, given the high risk of associated morbidity in this age group. However, expanding deworming to all age groups may achieve improved STH control among both the community in general and school-age children, by reducing their risk of reinfection. This trial aims to compare school-based targeted deworming with community-wide mass deworming in terms of impact on STH infections among school-age children. METHODS: The CoDe-STH (Community Deworming against STH) trial is a cluster-randomised controlled trial (RCT) in 64 primary schools in Dak Lak province, Vietnam. The control arm will receive one round of school-based targeted deworming with albendazole, while in the intervention arm, community-wide mass deworming with albendazole will be implemented alongside school-based deworming. Prevalence of STH infections will be measured in school-age children at baseline and 12 months following deworming. The primary outcome is hookworm prevalence in school-age children at 12 months, by quantitative PCR. Analysis will be intention-to-treat, with outcomes compared between study arms using generalised linear and non-linear mixed models. Additionally, cost-effectiveness of mass and targeted deworming will be calculated and compared, and focus group discussions and interviews will be used to assess acceptability and feasibility of deworming approaches. Individual based stochastic models will be used to predict the impact of mass and targeted deworming strategies beyond the RCT timeframe to assess the likelihood of parasite population 'bounce-back' if deworming is ceased due to low STH prevalence. DISCUSSION: The first large-scale trial comparing mass and targeted deworming for STH control in South East Asia will provide key information for policy makers regarding the optimal design of STH control programs. TRIAL REGISTRATION: ACTRN12619000309189 .