Browsing by Author "Liccioli, Stefano"

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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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    Insights into food web structure through knowing the helminth parasites
    (2013-11) Chan, S.K. Florence; Lejeune, Manigandan; Carlsson, Anja; Liccioli, Stefano; Behrens, Stephanie; Kutz, Susan J.
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    The transmission ecology of Echinococcus multilocularis in a North American urban landscape
    (2015-01-28) Liccioli, Stefano; Ruckstuhl, Kathreen; Massolo, Alessandro
    The cestode Echinococcus multilocularis is a trophically-transmitted parasite that is typically maintained in a sylvatic cycle involving wild canid definitive hosts and small mammal intermediate hosts. As etiological agent of Alveolar Echinococcosis in humans, the cestode is currently the third most impacting food-borne parasite globally. Understanding E. multilocularis transmission ecology, combined with reliable diagnostic and surveillance of parasite infection in wild hosts, is crucial for disease prevention and risk management. In Calgary, Canada, E. multilocularis was found to infect 29.5% (n = 61) of road-killed urban coyotes (Canis latrans) collected in 2009-2010. For the detection of E. multilocularis eggs in coyote feces, sugar fecal flotation showed lower sensitivity than the ZnCl2 centrifugation and sedimentation protocol (0.46 vs. 0.75). The latter technique is therefore recommended for screening of canid hosts. This study provided the first evidence of an urban sylvatic cycle of E. multilocularis in North America. Parasite prevalence in coyote feces was shown to vary temporally (10.5-43.5%) and spatially (5.3-61.5%) across five city parks, and infection of small mammal intermediate hosts was documented in three competent species (prevalence ranging between 0.7 and 1.4%). Genotyping coyote feces (n = 142) at 4-6 microsatellite loci allowed to correct for repeated sampling of individuals, and to estimate an overall parasite prevalence of 25.0%. Importantly, individual patterns of infection (i.e., parasite egg intensity in feces) allowed to observe temporal variations in parasite transmission that were not detected when examining fecal samples of unknown identity. By looking at the recovery of parasite eggs in genotyped feces over time, a re-infection rate of 57% (n =7) was estimated for coyotes in an area of parasite hyper-endemicity. Winter was a crucial period for E. multilocularis transmission, as the encounter rate of coyote with the parasite (number of infected hosts ingested) was higher than any other season (95% CI: 1.0-22.4). Voles (Microtus pennsylvanicus and Myodes gapperi) were consumed by coyotes proportionally more than their availability, and likely played a key role for the maintenance of the urban sylvatic life-cycle of E. multilocularis in this urban landscape.