Browsing by Author "Shury, Todd"

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    High species diversity of trichostrongyle parasite communities within and between Western Canadian commercial and conservation bison herds revealed by nemabiome metabarcoding
    (2018-05-15) Avramenko, Russell W; Bras, Ana; Redman, Elizabeth M; Woodbury, Murray R; Wagner, Brent; Shury, Todd; Liccioli, Stefano; Windeyer, M. C; Gilleard, John S
    Abstract Background Many trichostrongylid nematode species are reported to infect bison, some of which are major causes of disase and production loss in North American bison herds. However, there is little information on the species distribution and relative abundance of these parasites in either commercial or conservation herds. This is largely because trichostrongylid nematode species cannot be distinguished by visual microscopic examination of eggs present in feces. Consequently, we have applied ITS2 rDNA nemabiome metabarcoding to describe the trichostrongyle parasite species diversity in 58 bison production groups derived from 38 commercial North American plains bison (Bison bison bison) herds from across western Canada, and two bison conservation herds located in Elk Island National Park (EINP) [plains bison and wood bison (Bison bison athabascae)] and one in Grasslands National Park (GNP) (plains bison). Results We report much higher infection intensities and parasite species diversity in commercial bison herds than previously reported in beef cattle herds grazing similar latitudes. Predominant trichostrongyle parasite species in western Canadian commercial bison herds are those commonly associated with Canadian cattle, with Ostertagia ostertagi being the most abundant followed by Cooperia oncophora. Combined with high fecal egg counts in many herds, this is consistent with significant clinical and production-limiting gastrointestinal parasitism in western Canadian bison herds. However, Haemonchus placei was the most abundant species in five of the production groups. This is both surprising and important, as this highly pathogenic blood-feeding parasite has not been reported at such abundance, in any livestock species, at such northerly latitudes. The presence of Trichostrongylus axei as the most abundant parasite in four herds is also unusual, relative to cattle. There were striking differences in parasite communities between the EINP and commercial bison herds. Most notably, Orloffia bisonis was the predominant species in the wood bison herd despite being found at only low levels in all other herds surveyed. Conclusions This study represents the most comprehensive description of parasite communities in North American bison to date and illustrates the power of deep amplicon sequencing as a tool to study species diversity in gastrointestinal nematode communities.
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    Mycobacterium avium subsp. paratuberculosis in a captive wood bison herd: diagnostics and disease dynamics overtime
    (2024-01-23) Hernandez Reyes, Ana Laura; Orsel, Karsina; Kutz, Susan; De Buck, Jeroen; Shury, Todd
    Mycobacterium avium subsp. paratuberculosis (Map) has been identified in a wide range of domestic and wild ruminants. Captive wildlife can experience JD-related epidemiological scenarios similar to those in cattle. In wood bison (Bison bison athabascae), an iconic and keystone species in Canada, Map DNA has been reported in fecal samples from clinically healthy animals. However, there is apparently no published information regarding clinical presentation of JD and its significance in wood bison. The objective of this study was to determine to what extent Map can affects a captive bison herd located in northeastern Alberta, Canada. The first part of the study was the detection and isolation of Map in clinical cases. Necropsies were performed on six wood bison and 24 samples were collected from each bison. The highest frequency of positive samples was observed with tissue culture 62.5% (90/144) followed by F57/IS900 qPCR 43.1% (56/130), and histopathology 29% (38/131). Distal jejunum and its associated lymph nodes were the most reliable tissue samples for detecting Map, irrespective of tissue autolysis or absence of visible lesions. Strain typing revealed a type II (cattle) strain, second clade. The second part of the study focused on Map status in the herd by obtaining within-herd prevalence, evaluating the impact of a test and cull strategy and potential risk factors associated with Map. At the outset, within-herd prevalence was 4.7% based on IS900/F57 qPCR and 6.8% with IS900 qPCR with culture confirmation. The following year, after we calculated a 56.3% of culling rate of positive animals, the within herd prevalence observed by IS900/F57 qPCR was 4.2% and 9.9% by IS900 qPCR with culture confirmation. Bison in the age group ≥ 6-9 years were more likely to be Map positive. Furthermore, the location with the higher number of animals was significantly associated with being Map positive. Information from this study can contribute to control strategies in the bison herd studied, by obtaining the appropriate tissue samples selection at the necropsy and by targeting the age group most likely to be Map positive. Additionally, based on the prevalence obtained in this study, sampling size calculations can be performed to carry out studies at a herd level. However, it is important to understand that the best strategy to reduce the prevalence of JD depends on specific objectives and characteristics of each bison herd.