Kipp Kaylee R, Redman Elizabeth M, Luksovsky Joe L, Claussen Dani, Jones Lee C, Buttke Danielle E, Budke Christine M, Cook Walter E, Gilleard John S, Verocai Guilherme G
Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA.
Host Parasite Interactions Program, Faculty of Veterinary Medicine, 3330, Hospital Drive, University of Calgary, Calgary, Alberta, Canada.
Int J Parasitol Parasites Wildl. 2025 Sep 5;28:101134. doi: 10.1016/j.ijppaw.2025.101134. eCollection 2025 Dec.
Gastrointestinal nematodes (GIN) live in complex communities within American plains bison (), a keystone ungulate species of North American prairie ecosystems. These trichostrongylid nematode species vary in their level of pathogenicity and can cause disease ranging from subclinical to clinical. However, the GIN species diversity and distribution of North American bison are understudied, especially in conservation herds in the United States. Fecal samples from conservation bison were collected from six herds in 2022, with five of those herds resampled in 2023 across six states (Colorado, Iowa, Nebraska, North Dakota, South Dakota, Oklahoma). Fecal samples from a herd of longhorn cattle that co-graze with a bison herd from Oklahoma were also collected in both years. Following fecal egg counts and coproculture, third-stage larvae were processed using ITS2 rDNA metabarcoding to determine the trichostrongylid species composition and screened for the 200Y (TTC > TAC) polymorphisms of the isotype-1 β-tubulin gene to assess possible benzimidazole resistance. Alpha diversity was determined for each herd using the Shannon and the inverse Simpson diversity Index. The Beta diversity was assessed between herds using the Bray-Curtis dissimilarity index. The three most common species found were , , and . The herds with the highest parasite species diversity were in Oklahoma, Iowa, and North Dakota. The herd in Colorado showed the least diverse parasite communities. Over the course of the two-year study, moderate to high GIN species diversity was observed across several of the conservation bison herds. Additionally, different parasite species proportions were determined between co-grazing bison and cattle herds. Lastly, low frequencies of the 200Y (TTC > TAC) polymorphisms, associated with benzimidazole resistance, were detected. Our study reveals differences in species diversity and richness among conservation bison herds across the United States and provides the first evidence of benzimidazole resistance markers in wild bison in North America.
胃肠道线虫（GIN）生活在北美草原生态系统的关键有蹄类物种——美洲平原野牛的复杂群落中。这些毛圆科线虫物种的致病性程度各不相同，可引发从亚临床到临床的各种疾病。然而，北美野牛的胃肠道线虫物种多样性和分布情况尚未得到充分研究，尤其是在美国的保护畜群中。2022年从六个畜群采集了保护野牛的粪便样本，其中五个畜群在2023年于六个州（科罗拉多州、爱荷华州、内布拉斯加州、北达科他州、南达科他州、俄克拉荷马州）再次采样。在这两年中还采集了与俄克拉荷马州一群野牛共同放牧的一群长角牛的粪便样本。在进行粪便虫卵计数和粪便培养后，使用ITS2 rDNA元条形码对第三期幼虫进行处理，以确定毛圆科物种组成，并筛选同型-1β-微管蛋白基因的200Y（TTC>TAC）多态性，以评估可能的苯并咪唑抗性。使用香农多样性指数和辛普森倒数多样性指数确定每个畜群的α多样性。使用布雷-柯蒂斯相异指数评估畜群之间的β多样性。发现的三种最常见物种是[此处原文缺失物种名称]、[此处原文缺失物种名称]和[此处原文缺失物种名称]。寄生虫物种多样性最高的畜群位于俄克拉荷马州、爱荷华州和北达科他州。科罗拉多州的畜群寄生虫群落多样性最低。在为期两年的研究过程中，在几个保护野牛畜群中观察到了中度到高度的胃肠道线虫物种多样性。此外，还确定了共同放牧的野牛和牛群之间不同的寄生虫物种比例。最后，检测到与苯并咪唑抗性相关的200Y（TTC>TAC）多态性的低频出现。我们的研究揭示了美国各地保护野牛畜群之间物种多样性和丰富度的差异，并提供了北美野生野牛中苯并咪唑抗性标记的首个证据。
