317 research outputs found
Studies on feline calicivirus with particular reference to persistence.
The molecular evolution of feline calicivirus (FCV) was studied in cell culture and in persistently infected cats. Sequence analysis of the 5' hypervariable region of the FCV capsid (5'HVR; located at the 5' end of variable region E), a region known to contain linear neutralising B cell epitopes, showed FCV existed as a quasispecies which evolved at the nucleotide and amino acid level during persistent infection. Quasispecies heterogeneity tended to decrease the course of persistence. Sequential isolates from a cat showed marked antigenic variation during the course of persistent infection. Sequential passage of FCV in cell culture was also associated with sequence evolution of the 5'HVR. However, these isolates showed no change in antigenicity suggesting that individual substitutions observed in viruses from cats, but not in viruses from cell culture, may be responsible for changes in antigenicity. Alternatively, the observed antigenic changes may be associated with mutations elsewhere in the genome. In order to identify regions of the FCV capsid protein containing liner B-cell epitopes, two approaches were used. Firstly, an expression library containing random, short (100-300bp) fragments of an FCV capsid gene was constructed. This library was screened using polyclonal antisera from a cat that had been challenged experimentally with FCV to identify immunoreactive clones containing B-cell epitopes. Initial screening identified five clones that reacted positively to feline antisera in immunoblots. FCV derived sequence from these clones all mapped to the 5'HVR, suggesting this region contains the immunodominant linear epitopes of the capsid. The second approach used to identify B-cell epitopes was to map more accurately the epitope of a neutralising monoclonal antibody (IG9) which had already been shown to lie in a 37 amino acid region of the 5'HVR (Milton et al. (1992), Journal of General Virology 73, 2435-2439). Replication of plaque purified IG9-sensitive parent virus in sub-neutralising concentrations of IG9 led to the generation of a neutralisation resistant escape mutant. Sequence analysis of this mutant and the parent virus revealed a single non-synonymous nucleotide substitution within the 5'HVR, suggesting this residue is critical to the correct formation of the IG9 epitope
Using open-access taxonomic and spatial information to create a comprehensive database for the study of Mammalian and avian livestock and pet infections
AbstractWhat are all the species of pathogen that affect our livestock? As 6 out of every 10 human pathogens came from animals, with a good number from livestock and pets, it seems likely that the majority that emerge in the future, and which could threaten or devastate human health, will come from animals. Only 10 years ago, the first comprehensive pathogen list was compiled for humans; we still have no equivalent for animals. Here we describe the creation of a novel pathogen database, and present outputs from the database that demonstrate its value.The ENHanCEd Infectious Diseases database (EID2) is open-access and evidence-based, and it describes the pathogens of humans and animals, their host and vector species, and also their global occurrence. The EID2 systematically collates information on pathogens into a single resource using evidence from the NCBI Taxonomy database, the NCBI Nucleotide database, the NCBI MeSH (Medical Subject Headings) library and PubMed. Information about pathogens is assigned using data-mining of meta-data and semi-automated literature searches.Here we focus on 47 mammalian and avian hosts, including humans and animals commonly used in Europe as food or kept as pets. Currently, the EID2 evidence suggests that:•Within these host species, 793 (30.5%) pathogens were bacteria species, 395 (15.2%) fungi, 705 (27.1%) helminths, 372 (14.3%) protozoa and 332 (12.8%) viruses.•The odds of pathogens being emerging compared to not emerging differed by taxonomic division, and increased when pathogens had greater numbers of host species associated with them, and were zoonotic rather than non-zoonotic.•The odds of pathogens being zoonotic compared to non-zoonotic differed by taxonomic division and also increased when associated with greater host numbers.•The pathogens affecting the greatest number of hosts included: Escherichia coli, Giardia intestinalis, Toxoplasma gondii, Anaplasma phagocytophilum, Cryptosporidium parvum, Rabies virus, Staphylococcus aureus, Neospora caninum and Echinococcus granulosus.•The pathogens of humans and domestic animal hosts are characterised by 4223 interactions between pathogen and host species, with the greatest number found in: humans, sheep/goats, cattle, small mammals, pigs, dogs and equids.•The number of pathogen species varied by European country. The odds of a pathogen being found in Europe compared to the rest of the world differed by taxonomic division, and increased if they were emerging compared to not emerging, or had a larger number of host species associated with them
Surveillance of heat-related illness in small animals presenting to veterinary practices in the UK between 2013-2018
Background: Heat-related illness (HRI) can affect all companion animals and is likely to become more common as global temperatures rise. The misconception that HRI is primarily a result of dogs being trapped in hot cars, highlights a lack of awareness of HRI risk factors within the UK companion animal population.
Aim: This project aimed to review all species of small animal presentations of HRI to UK veterinary practices participating in the Small Animal Veterinary Surveillance Network (SAVSNET), describe the inciting triggers and seasonality of HRI events, and review the clinical grade of canine patients presenting with HRI.
Methods: Electronic consultation records were submitted by volunteer veterinary practices across Great Britain to SAVSNET. Cases were defined as animals presented for consultation with strong evidence of current, or recent heat induced illness during the study period (2013-2018).
Results: The HRI cases included 146 dogs, 16 cats, eight guinea pigs, three rabbits and one ferret. Of the 118 HRI cases with a recorded trigger, exercise was the primary trigger for dogs presenting (73.5%); seven (6.9%) canine HRI events followed vehicular confinement. Environmental HRI was recorded as a trigger for the remaining dogs (19.6%), and for all cats, guinea pigs, rabbits and the ferret. Brachycephalic breeds comprised 21.2% of canine HRI cases, and all rabbits were brachycephalic breeds. Dogs presented for HRI between April and October, with 42.5% during July, typically the UK’s hottest month of the year. Cats with HRI were presented between May and September, with 75.0% during June and July. The smaller companion species - ferrets, rabbits and guinea pigs – were presented during the UK’s summer months June to August.
Conclusion: This study highlights the risk of HRI to all pet animals during the UK’s warmer summer months (June to August). The findings support previous claims that exercise is the most common trigger of HRI in dogs, whilst environmental HRI (a hot ambient temperature) accounted for all HRI events in cats, rabbits, guinea pigs and ferrets. Both brachycephalic dogs and rabbits were overrepresented, adding further evidence that owners of these animals should be particularly vigilant for HRI during hot weather
Tick parasitism classification from noisy medical records
Much of the health information in the medical domain comes in the form of clinical narratives. The rich semantic information contained in these notes can be modeled to make inferences that assist the decision making process for medical practitioners, which is particularly important under time and resource constraints. However, the creation of such assistive tools is made difficult given the ubiquity of misspellings, unsegmented words and morphologically complex or rare medical terms. This reduces the coverage of vocabulary terms present in commonly used pretrained distributed word representations that are passed as input to parametric models that makes such predictions. This paper presents an ensemble architecture that combines indomain and general word embeddings to overcome these challenges, showing best performance on a binary classification task when compared to various other baselines. We demonstrate our approach in the context of the veterinary domain for the task of identifying tick parasitism from small animals. The best model shows 84.29% test accuracy, showing some improvement over models, which only use pretrained embeddings that are not specifically trained for the medical sub-domain of interest
Novel Host-Related Virulence Factors Are Encoded by Squirrelpox Virus, the Main Causative Agent of Epidemic Disease in Red Squirrels in the UK
Squirrelpox virus (SQPV) shows little evidence for morbidity or mortality in North American grey squirrels (Sciurus carolinensis), in which the virus is endemic. However, more recently the virus has emerged to cause epidemics with high mortality in Eurasian red squirrels (S. vulgaris) in Great Britain, which are now threatened. Here we report the genome sequence of SQPV. Comparison with other Poxviridae revealed a core set of poxvirus genes, the phylogeny of which showed SQPV to be in a new Chordopoxvirus subfamily between the Molluscipoxviruses and Parapoxviruses. A number of SQPV genes were related to virulence, including three major histocomaptibility class I homologs, and one CD47 homolog. In addition, a novel potential virulence factor showing homology to mammalian oligoadenylate synthetase (OAS) was identified. This family of proteins normally causes activation of an endoribonuclease (RNaseL) within infected cells. The putative function of this novel SQPV protein was predicted in silico
"Just old age" - a qualitative investigation of owner and veterinary professional experiences of and attitudes to ageing in dogs in the UK.
ObjectivesMany UK dogs live into old age, but owners may not recognise or report age-associated signs of disease which lead to negative welfare. This study investigated dog owner and veterinary professional experiences and attitudes towards ageing in dogs, how health care is offered, barriers to its delivery, and some best-practice solutions.Materials and methodsIn-depth semi-structured interviews were conducted with 15 owners of 21 dogs (aged 8 to 17 years mean: 13) and 11 veterinary professional (eight veterinary surgeons, two nurses and one physiotherapist). Open-text responses from 61 dog owner were collected using an online survey. Transcripts and survey responses were inductively coded into themes.ResultsFour themes were constructed: "just old age", barriers to care, trust in veterinary surgeons, and tools to improve health care. Age-related changes were mostly perceived as "just old age" by dog owner. Many dogs were no longer vaccinated and did not attend check-ups unless owners identified a problem. The greatest barriers to health care were finances (dog owner), owner awareness, willingness to act and consultation time (veterinary professional). Trust in veterinary professional was more likely when dog owner experienced continuity, prioritisation of care, clear communication and an accessible, knowledgeable and empathic veterinary professional. Participants suggested that senior health care and communication between dog owner and veterinary professional could be improved through questionnaires, and evidence-based online information.Clinical significanceOpportunities to educate owners on which clinical signs represent healthy or pathological ageing are being missed. Resources should be developed to guide on best-practice discussions in consultations, encourage more owners to recognise clinical signs and to seek and trust veterinary advice
Prescribing practices of primary-care veterinary practitioners in dogs diagnosed with bacterial pyoderma
Concern has been raised regarding the potential contributions of veterinary antimicrobial use to increasing levels of resistance in bacteria critically important to human health. Canine pyoderma is a frequent, often recurrent diagnosis in pet dogs, usually attributable to secondary bacterial infection of the skin. Lesions can range in severity based on the location, total area and depth of tissue affected and antimicrobial therapy is recommended for resolution. This study aimed to describe patient signalment, disease characteristics and treatment prescribed in a large number of UK, primary-care canine pyoderma cases and to estimate pyoderma prevalence in the UK vet-visiting canine population
Analysis of gene expression from the Wolbachia genome of a filarial nematode supports both metabolic and defensive roles within the symbiosis
The α-proteobacterium Wolbachia is probably the most prevalent, vertically transmitted symbiont on Earth. In contrast with its wide distribution in arthropods, Wolbachia is restricted to one family of animal-parasitic nematodes, the Onchocercidae. This includes filarial pathogens such as Onchocerca volvulus, the cause of human onchocerciasis, or river blindness. The symbiosis between filariae and Wolbachia is obligate, although the basis of this dependency is not fully understood. Previous studies suggested that Wolbachia may provision metabolites (e.g., haem, riboflavin, and nucleotides) and/or contribute to immune defense. Importantly, Wolbachia is restricted to somatic tissues in adult male worms, whereas females also harbor bacteria in the germline. We sought to characterize the nature of the symbiosis between Wolbachia and O. ochengi, a bovine parasite representing the closest relative of O. volvulus. First, we sequenced the complete genome of Wolbachia strain wOo, which revealed an inability to synthesize riboflavin de novo. Using RNA-seq, we also generated endobacterial transcriptomes from male soma and female germline. In the soma, transcripts for membrane transport and respiration were up-regulated, while the gonad exhibited enrichment for DNA replication and translation. The most abundant Wolbachia proteins, as determined by geLC-MS, included ligands for mammalian Toll-like receptors. Enzymes involved in nucleotide synthesis were dominant among metabolism-related proteins, whereas the haem biosynthetic pathway was poorly represented. We conclude that Wolbachia may have a mitochondrion-like function in the soma, generating ATP for its host. Moreover, the abundance of immunogenic proteins in wOo suggests a role in diverting the immune system toward an ineffective antibacterial response
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