Canadian Food Inspection Agency, Ottawa Laboratory (Fallowfield), 3851 Fallowfield Rd., Ottawa, Ontario K2H 8P9, Canada.
Canadian Food Inspection Agency, Ottawa Laboratory (Fallowfield), 3851 Fallowfield Rd., Ottawa, Ontario K2H 8P9, Canada.
Vet Microbiol. 2018 Feb;214:44-50. doi: 10.1016/j.vetmic.2017.12.005. Epub 2017 Dec 8.
Two internationally recognised and standardised genotyping methods, mycobacterial interspersed repetitive unit and variable number tandem repeat analysis (MIRU-VNTR) and spoligotyping, were applied to characterise genetic variations among 137 Mycobacterium bovis isolates recovered from Canadian domestic and wild animals during 1985-2015. Spoligotyping generated seven types that were discriminated further into12 MIRU-VNTR types. The discriminatory power indexes were estimated as 0.71 and 0.77 for spoligotyping and MIRU-VNTR typing approaches, respectively. In total, 6 prominent clusters of isolates were observed by the genotyping schemes. Four genotype clusters were exclusively observed in farmed animals. Three of these four clusters were affiliated with localised tuberculosis outbreaks, and each cluster corresponded to a single specific spoligotype (SB0140, SB0673, and SB1069) and a MIRU-VNTR profile. The fourth genotype cluster, with spoligotype SB0265 which segregated into two MIRU-VNTR types, was associated with bovine tuberculosis outbreaks in several farms across Canada during 1990-2002. Two genotype clusters of M. bovis stains were associated with wildlife reservoirs: a spoligotype SB0130 with 3 unique MIRU-VNTR profiles were observed in wood bison in Wood Buffalo National Park, and unique spoligotypes SB1070 and 1071 represented by four MIRU-VNTR profiles were recovered from cervidae species in and around the Riding Mountain National Park of Manitoba. Genotyping data confirmed M. bovis transmission between wildlife and livestock in Manitoba in 1990-2008. Overall, notwithstanding the low level of genetic diversity of Canadian M. bovis strains, the spoligotyping and MIRU-VNTR typing were useful tools in monitoring transmission of endemic strains and defining new introductions to Canada. The majority of genotypes were most likely introduced into domestic animals through live animal trade, and subsequently eliminated as a result of bovine tuberculosis outbreak investigation and eradication activities.
两种国际认可和标准化的基因分型方法，即分枝杆菌插入重复单元和可变数串联重复分析（MIRU-VNTR）和 spoligotyping，应用于 1985 年至 2015 年期间从加拿大国内和野生动物中分离的 137 株牛分枝杆菌分离株的遗传变异特征分析。 spoligotyping 产生了 7 种类型，进一步分为 12 种 MIRU-VNTR 类型。 spoligotyping 和 MIRU-VNTR 分型方法的区分指数分别估计为 0.71 和 0.77。总共观察到 6 个主要的分离株基因型聚类。 4 个基因型聚类仅在养殖动物中观察到。 这 4 个聚类中的 3 个与局部结核爆发有关，每个聚类对应于一个特定的 spoligotype（SB0140、SB0673 和 SB1069）和 MIRU-VNTR 图谱。第四个基因型聚类， spoligotype SB0265 分为两种 MIRU-VNTR 类型，与 1990 年至 2002 年期间加拿大多个农场的牛结核爆发有关。与野生动物宿主相关的 M. bovis 菌株的两个基因型聚类：在伍德布法罗国家公园的木野牛中观察到带有 3 个独特 MIRU-VNTR 图谱的 spoligotype SB0130，以及从马尼托巴省的里丁山国家公园及其周围的鹿科物种中回收的带有 4 个 MIRU-VNTR 图谱的独特 spoligotypes SB1070 和 1071。基因分型数据证实了 1990 年至 2008 年期间曼尼托巴省野生动物和牲畜之间的 M. bovis 传播。总的来说，尽管加拿大 M. bovis 菌株的遗传多样性水平较低，但 spoligotyping 和 MIRU-VNTR 分型是监测地方性菌株传播和确定新传入加拿大的有用工具。大多数基因型很可能通过活体动物贸易引入到家养动物中，随后由于牛结核爆发调查和根除活动而被淘汰。
