Sharma Rajnish, Thompson Peter, Elkin Brett, Mulders Robert, Branigan Marsha, Pongracz Jodie, Wagner Brent, Scandrett Brad, Hoberg Eric, Rosenthal Benjamin, Jenkins Emily
Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada.
USDA-Agricultural Research Service, Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, 10300 Baltimore Avenue, Beltsville, MD, 20705, USA.
Int J Parasitol Parasites Wildl. 2019 Jun 13;9:274-280. doi: 10.1016/j.ijppaw.2019.06.005. eCollection 2019 Aug.
Species of are a globally distributed assemblage of nematodes, often with distinct host ranges, which include people, domestic, and wild animals. spp. are important in northern Canada, where dietary habits of people and methods of meat preparation (drying, smoking, fermenting as well as raw) increase the risk posed by these foodborne zoonotic parasites. Outbreaks in the arctic and subarctic regions of Canada and the United States are generally attributed to (T2) or the T6 genotype, when genetic characterization is performed. We report the discovery of (T4), a non-encapsulated species, in a wolverine () from the Northwest Territories of Canada. This parasite has been previously reported elsewhere from both mammals and carnivorous birds, but our findings represent new host and geographic records for . Multiplex PCR and sequencing of fragments of Cytochrome Oxidase Subunit I (COI) and D3 rDNA confirmed the identification. Phylogenetically, Canadian isolates linked with each other and others derived from Palearctic or Neotropical regions, but not elsewhere in the Nearctic (continental USA). We suggest that migratory birds might have played a role in the dispersal of this pathogen 1000's of km to northwestern Canada. Wolverines are not typically consumed by humans, and thus should not pose a direct food safety risk for trichinellosis. However, the current finding suggests that they may serve as an indicator of a broader distribution for . Along with infection risk already recognized for and T6, our observations emphasize the need for further studies using molecular diagnostics and alternative methods to clarify if this is a solitary case, or if and other freeze susceptible species of (such as ) circulate more broadly in wildlife in Canada, and elsewhere.
旋毛虫属线虫是一类全球分布的线虫组合,通常具有不同的宿主范围,包括人类、家畜和野生动物。旋毛虫属线虫在加拿大北部很重要,在那里人们的饮食习惯和肉类制备方法(干燥、烟熏、发酵以及生食)增加了这些食源性人畜共患寄生虫带来的风险。在加拿大和美国的北极及亚北极地区爆发的疫情,在进行基因特征分析时,通常归因于旋毛虫(T2)或T6基因型。我们报告了在加拿大西北地区的一只狼獾(貂熊)体内发现了非包囊型的布氏旋毛虫(T4)。这种寄生虫此前在其他地方的哺乳动物和食肉鸟类中都有报道,但我们的发现代表了布氏旋毛虫新的宿主和地理记录。通过多重PCR以及细胞色素氧化酶亚基I(COI)和D3核糖体DNA片段的测序证实了这一鉴定结果。在系统发育上,加拿大的分离株彼此相连,也与源自古北区或新热带区的分离株相连,但与近北区(美国大陆)的其他地方不相连。我们认为候鸟可能在将这种病原体传播到加拿大西北部数千公里远的地方起到了作用。狼獾通常不被人类食用,因此不应构成旋毛虫病的直接食品安全风险。然而,目前的发现表明它们可能是布氏旋毛虫分布更广的一个指标。连同已经认识到的旋毛虫和T6型旋毛虫的感染风险,我们的观察结果强调需要使用分子诊断和替代方法进行进一步研究,以弄清楚这是否是一个孤立的案例,或者布氏旋毛虫和其他对冷冻敏感的旋毛虫属物种(如旋毛形线虫)是否在加拿大及其他地方的野生动物中更广泛地传播。