Browsing by Author "Gilleard, John S."
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Item Open Access Metabarcoding in two isolated populations of wild roe deer (Capreolus capreolus) reveals variation in gastrointestinal nematode community composition between regions and among age classes(2021-12-04) Beaumelle, Camille; Redman, Elizabeth M.; de Rijke, Jill; Wit, Janneke; Benabed, Slimania; Debias, François; Duhayer, Jeanne; Pardonnet, Sylvia; Poirel, Marie-Thérèse; Capron, Gilles; Chabot, Stéphane; Rey, Benjamin; Yannic, Glenn; Gilleard, John S.; Bourgoin, GillesAbstract Background Gastrointestinal nematodes are ubiquitous for both domestic and wild ungulates and have varying consequences for health and fitness. They exist as complex communities of multiple co-infecting species, and we have a limited understanding of how these communities vary in different hosts, regions and circumstances or of how this affects their impacts. Methods We have undertaken ITS2 rDNA nemabiome metabarcoding with next-generation sequencing on populations of nematode larvae isolated from 149 fecal samples of roe deer of different sex and age classes in the two isolated populations of Chizé and Trois Fontaines in France not co-grazing with any domestic ungulate species. Results We identified 100 amplified sequence variants (ASVs) that were assigned to 14 gastrointestinal nematode taxa overall at either genus (29%) or species (71%) level. These taxa were dominated by parasites classically found in cervids—e.g. Ostertagia leptospicularis, Spiculopteragia spp. Higher parasite species diversity was present in the Trois Fontaines population than in the Chizé population including the presence of species more typically seen in domestic livestock (Haemonchus contortus, Bunostomum sp., Cooperia punctata, Teladorsagia circumcincta). No differences in parasite species diversity or community composition were seen in the samples collected from three zones of differing habitat quality within the Chizé study area. Young roe deer hosted the highest diversity of gastrointestinal nematodes, with more pronounced effects of age apparent in Trois Fontaines. The effect of host age differed between gastrointestinal nematode species, e.g. there was little effect on O. leptospicularis but a large effect on Trichostrongylus spp. No effect of host sex was detected in either site. Conclusions The presence of some livestock parasite species in the Trois Fontaines roe deer population was unexpected given the isolation of this population away from grazing domestic livestock since decades. Overall, our results illustrate the influence of host traits and the local environment on roe deer nemabiome and demonstrate the power of the nemabiome metabarcoding approach to elucidate the composition of gastrointestinal nematode communities in wildlife. Graphical AbstractItem Open Access Parasite Control Strategies on Cow-Calf Operations: A Systematic Review of Pharmaceutical Interventions against Gastrointestinal Nematodes in Pre-weaned Beef Calves and Qualitative Exploration of Producers' Perspectives(2023-07) Agbese, Samuel Peter; Windeyer, Claire M.K.; Gilleard, John S.; Ritter, Caroline Manuela Nancy; Uehlinger, Fabienne D.Parasitism poses a significant threat to the health and productivity of grazing livestock globally and is a primary contributor to diseases in these animals. To ensure the long-term viability of cow-calf operations, it is imperative to adopt and implement strategies for controlling parasites. In Alberta, Canada, one of the most common parasite control strategies is the use of pharmaceutical interventions (i.e., anthelmintics). However, the summarized information on the existing evidence on the effectiveness of pharmaceutical interventions in controlling gastrointestinal nematodes (GIN) in pre-weaned beef calves, as well as how parasite control strategies are perceived by cow-calf producers in Alberta, are unknown. The objective of the first study was to assess the current scientific literature on the effectiveness of pharmaceutical interventions on cow-calf operations to treat or control GIN in pre-weaned beef calves as measured by a reduction in fecal egg count. The review found that, of the 29 included articles, only 5 used the fecal egg count reduction test (FECRT) to evaluate the effectiveness of pharmaceutical interventions for treating GIN. The drugs assessed in the 5 articles included albendazole, fenbendazole, doramectin, eprinomectin, and ivermectin. Studies focusing on benzimidazole drugs consistently reported FECRT values above 96% with evidence of greater effectiveness than the macrocyclic lactone drugs, which reported a range of FECRT from 15% to 93%. This was the first study to assess and compile the existing literature on the effectiveness of pharmaceutical interventions in controlling GIN in pre-weaned beef calves. In the second study, the objective was to explore cow-calf producers’ perceptions about on-farm parasite control strategies and to describe the on-farm parasite control practices implemented by these respondents. Cow-calf producers in Alberta, Canada were sent a questionnaire to recruit interview participants and to identify their current parasite control strategies. Fifteen respondents were interviewed via telephone to explore their perceptions of parasite control strategies and rationale for the acceptance or rejection of parasite control practices. The study revealed that the majority of cow-calf producers rely on pharmaceutical parasite control products, and price was not the main factor in product selection. A lack of familiarity with some parasite control strategies was noted, such as pasture management, where producers often viewed parasite control as secondary or not at all when it came to pasture management, with the management of the grass being the main factor they emphasized. Additionally, veterinarians had influence over parasite control decisions but were not a major source of information on fecal sampling procedures, suggesting a need for improved communication.Item Open Access Regional heterogeneity and unexpectedly high abundance of Cooperia punctata in beef cattle at a northern latitude revealed by ITS-2 rDNA nemabiome metabarcoding(2022-01-06) De Seram, Eranga L.; Redman, Elizabeth M.; Wills, Felicity K.; de Queiroz, Camila; Campbell, John R.; Waldner, Cheryl L.; Parker, Sarah E.; Avramenko, Russell W.; Gilleard, John S.; Uehlinger, Fabienne D.Abstract Background The species composition of cattle gastrointestinal nematode (GIN) communities can vary greatly between regions. Despite this, there is remarkably little large-scale surveillance data for cattle GIN species which is due, at least in part, to a lack of scalable diagnostic tools. This lack of regional GIN species-level data represents a major knowledge gap for evidence-based parasite management and assessing the status and impact of factors such as climate change and anthelmintic drug resistance. Methods This paper presents a large-scale survey of GIN in beef herds across western Canada using ITS-2 rDNA nemabiome metabarcoding. Individual fecal samples were collected from 6 to 20 randomly selected heifers (n = 1665) from each of 85 herds between September 2016 and February 2017 and 10–25 first season calves (n = 824) from each of 42 herds between November 2016 and February 2017. Results Gastrointestinal nematode communities in heifers and calves were similar in Alberta and Saskatchewan, with Ostertagia ostertagi and Cooperia oncophora being the predominant GIN species in all herds consistent with previous studies. However, in Manitoba, Cooperia punctata was the predominant species overall and the most abundant GIN species in calves from 4/8 beef herds. Conclusions This study revealed a marked regional heterogeneity of GIN species in grazing beef herds in western Canada. The predominance of C. punctata in Manitoba is unexpected, as although this parasite is often the predominant cattle GIN species in more southerly latitudes, it is generally only a minor component of cattle GIN communities in northern temperate regions. We hypothesize that the unexpected predominance of C. punctata at such a northerly latitude represents a range expansion, likely associated with changes in climate, anthelmintic use, management, and/or animal movement. Whatever the cause, these results are of practical concern since C. punctata is more pathogenic than C. oncophora, the Cooperia species that typically predominates in cooler temperate regions. Finally, this study illustrates the value of ITS-2 rDNA nemabiome metabarcoding as a surveillance tool for ruminant GIN parasites. Graphical AbstractItem Open Access Seasonal epidemiology of gastrointestinal nematodes of cattle in the northern continental climate zone of western Canada as revealed by internal transcribed spacer-2 ribosomal DNA nemabiome barcoding(2021-12-11) Wang, Tong; Redman, Elizabeth M.; Morosetti, Arianna; Chen, Rebecca; Kulle, Sarah; Morden, Natasha; McFarland, Christopher; Vineer, Hannah R.; Colwell, Douglas D.; Morgan, Eric R.; Gilleard, John S.Abstract Background Gastrointestinal nematode (GIN) epidemiology is changing in many regions of the world due to factors such as global warming and emerging anthelmintic resistance. However, the dynamics of these changes in northern continental climate zones are poorly understood due to a lack of empirical data. Methods We studied the accumulation on pasture of free-living infective third-stage larvae (L3) of different GIN species from fecal pats deposited by naturally infected grazing cattle. The field study was conducted on three organic farms in Alberta, western Canada. Grass samples adjacent to 24 fecal pats were collected from each of three different pastures on each farm. Internal transcribed spacer-2 nemabiome metabarcoding was used to determine the GIN species composition of the harvested larvae. The rotational grazing patterns of the cattle ensured that each pasture was contaminated only once by fecal pat deposition. This design allowed us to monitor the accumulation of L3 of specific GIN species on pastures under natural climatic conditions without the confounding effects of pasture recontamination or anthelmintic treatments. Results In seven out of the nine pastures, grass L3 counts peaked approximately 9 weeks after fecal deposition and then gradually declined. However, a relatively large number of L3 remained in the fecal pats at the end of the grazing season. Nemabiome metabarcoding revealed that Cooperia oncophora and Ostertagia ostertagi were the two most abundant species on all of the pastures and that the dynamics of larval accumulation on grass were similar for both species. Daily precipitation and temperature across the whole sampling period were similar for most of the pastures, and multiple linear regression showed that accumulated rainfall 1 week prior to sample collection had a significant impact on the pasture L3 population, but accumulated rainfall 3 weeks prior to sample collection did not. Conclusions The results suggest that the pasture L3 population was altered by short-term microclimatic conditions conducive for horizontal migration onto grass. Overall, the results show the importance of the fecal pat as a refuge and reservoir for L3 of cattle GIN on western Canadian pastures, and provide an evidence base for the risk assessment of rotational grazing management in the region. Graphical AbstractItem Open Access The application of deep amplicon sequencing to the diagnostics and molecular epidemiology of anthelmintic resistance in sheep gastrointestinal nematodes(2021-01-14) de Queiroz, Camila A. A.; Gilleard, John S.; Levy, Michel; Johannes van der Meer, Franciscus; Wasmuth, James; Yeaman, Samuel J; Michael Vamosi, Steven; Brewer, MattGastrointestinal nematodes (GIN) are a major challenge for sheep producers worldwide. They cause a variety of clinical signs and large economic impact. Anthelmintics are commonly used in control, however, indiscriminate use of these drugs over many years has led to the problem of anthelmintic resistance. The lack of accurate resistance diagnostic methods increases the challenge of parasite control. This thesis investigates the problem of anthelmintic resistance in Western Canadian sheep for the first time. This region has been believed unsuitable for GIN due to suboptimal weather and low treatment selection pressure. Chapter 2 presents a large-scale survey of anthelmintic efficacy. The precision of the Fecal Egg Count Reduction Test (FECRT) diagnostic method was also investigated. Results revealed high GIN infection intensity and anthelmintic resistance against benzimidazoles and ivermectin, highlighting the urgent need for better diagnostic tools. Chapter 3 validates the recently developed nemabiome metabarcoding approach for the relative quantitation of GIN species in ovine fecal samples. Chapter 4 applies the validated approach integrated to FECRT to a large-scale study in Western Canada and revealed widespread resistance of H. contortus to benzimidazoles and ivermectin. Resistance to closantel was absent, but this drug was often ineffective due to its narrow spectrum activity.Chapter 5 applies deep amplicon sequencing to screen for benzimidazole resistance mutations in the isotype-1 b-tubulin gene of the main GIN in Western Canada and United States of America (USA). Codon F200Y(TTC>TAC) mutation was found at high frequency in H. contortus and at lower frequencies in other species. The relative frequencies of resistance mutations were similar between Western Canada and USA, although generally higher in USA, consistent with greater selection pressure. A pilot study also identified resistance mutations in the isotype-2 b-tubulin gene of H. contortus, suggesting this locus warrants further investigation regarding its role in benzimidazole resistance. Phylogenetic network analysis revealed that the most common resistance haplotypes were shared between Western Canada and USA, supporting a hypothesis of common origins of resistance. Given the more advanced resistance in the USA, a likely scenario is that anthelmintic resistant parasites were introduced to Western Canada from sheep imported from the USA.