Abstract：
The aim of this study was to assess the diversity of minisatellite VNTR loci in Mycobacterium bovis/M. caprae isolates in Bulgaria and view their position within global M. bovis diversity. Forty-three M. bovis/M. caprae isolates from cattle in different farms in Bulgaria were collected in 2015-2021 and typed in 13 VNTR loci. The M. bovis and M. caprae branches were clearly separated on the VNTR phylogenetic tree. The larger and more geographically dispersed M. caprae group was more diverse than M. bovis group was (HGI 0.67 vs. 0.60). Overall, six clusters were identified (from 2 to 19 isolates) and nine orphans (all loci-based HGI 0.79). Locus QUB3232 was the most discriminatory one (HGI 0.64). MIRU4 and MIRU40 were monomorphic, and MIRU26 was almost monomorphic. Four loci (ETRA, ETRB, Mtub21, and MIRU16) discriminated only between M. bovis and M. caprae. The comparison with published VNTR datasets from 11 countries showed both overall heterogeneity between the settings and predominantly local evolution of the clonal complexes. To conclude, six loci may be recommended for primary genotyping of M. bovis/M. caprae isolates in Bulgaria: ETRC, QUB11b, QUB11a, QUB26, QUB3232, and MIRU10 (HGI 0.77). VNTR typing based on a limited number of loci appears to be useful for primary bTB surveillance.
摘要：
这项研究的目的是评估牛分枝杆菌/M中小型卫星VNTR基因座的多样性。保加利亚的caprae分离株，并查看它们在全球牛分枝杆菌多样性中的地位。43牛牛/牛在2015-2021年从保加利亚不同农场的牛中收集了caprae分离株，并在13个VNTR基因座中进行了分型。牛分枝杆菌和牛分枝杆菌在VNTR系统发育树上明显分开。与牛分枝杆菌组相比，较大且在地理上更分散的M.caprae组更为多样化（HGI0.67vs.0.60)。总的来说,确定了6个簇（从2到19个分离株）和9个孤儿（所有基于基因座的HGI0.79）。基因座QUB3232是最具歧视性的一个(HGI0.64)。MIRU4和MIRU40是单态的，MIRU26几乎是单态的。四个基因座（ETRA，ETRB,Mtub21和MIRU16）仅区分牛分枝杆菌和牛分枝杆菌。与来自11个国家/地区的已发布的VNTR数据集的比较显示了设置之间的总体异质性和克隆复合物的主要局部进化。最后，6个基因座可推荐用于牛分枝杆菌/M.保加利亚的caprae分离株：ETRC，QUB11b,QUB11a,QUB26、QUB3232和MIRU10（HGI0.77）。基于有限数量的基因座的VNTR分型似乎对原发性bTB监测有用。
