The State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
The State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The University of Agriculture, Peshawar, Department of Animal Health, Khyber Pakhtunkhwa, Pakistan.
Microb Pathog. 2017 Oct;111:108-117. doi: 10.1016/j.micpath.2017.08.029. Epub 2017 Aug 18.
This study was undertaken to determine the genotypic distribution of Chinese M. bovis strains and their similarity to isolates from other countries. Two multilocus sequence typing (MLST) schemes (MLST-1 and MLST-2) and pulsed field gel electrophoresis (PFGE) were used to compare 44 Chinese strains and the M. bovis type strain PG45. The results showed a high genetic homogeneity of Chinese isolates; 43 of 44 (97.7%) Chinese isolates were identified as ST-10 and as ST-34 by MLST-1, while for MLST-2 42 of 44 (95.5%) were identified as ST-10 with the two remaining isolates of ST-32 and ST43. PFGE clustered 42 of 44 (95.5%) of the Chinese isolates into PT-I. The overall agreement rate between the three typing methods was 97.8% (95% CI:86.8-99.9%). The type strain PG45 was identified as a unique type by all three methods. When the MLST-2 scheme was further used to analyze 16 isolates of Australian and Israeli origin ST-10 was more dominant among Australian isolates (7/8), compared with those from Israel (3/8). The evolutionary relationship of the 60 isolates typed in this study assessed together with 206 additional isolates retrieved from pubmlst/mbovis database analyzed by geoBURST Minimum spanning tree (MST) confirmed that the Chinese, Israeli and Australian M. bovis isolates typed in this study that were predominantly ST-10, were clustered in CC3 with isolates originating from the USA. Our results suggest that ST-10 is an emerging clone of M. bovis population. We hypothesized that the widespread distribution of this type is a result of global livestock movements. These findings will help further the understanding of the global evolution of M. bovis and development of novel vaccines against M. bovis.
本研究旨在确定中国牛分枝杆菌菌株的基因型分布及其与其他国家分离株的相似性。我们使用两种多位点序列分型（MLST）方案（MLST-1 和 MLST-2）和脉冲场凝胶电泳（PFGE）比较了 44 株中国分离株和牛分枝杆菌标准株 PG45。结果表明，中国分离株具有高度的遗传同质性；44 株中国分离株中，43 株（97.7%）通过 MLST-1 鉴定为 ST-10，34 株（81.8%）通过 MLST-2 鉴定为 ST-10，其余 2 株为 ST-32 和 ST43。PFGE 将 44 株中国分离株中的 42 株（95.5%）聚类为 PT-I。三种分型方法的总符合率为 97.8%（95%可信区间：86.8-99.9%）。标准株 PG45 被三种方法均鉴定为独特类型。当进一步使用 MLST-2 方案分析 16 株来自澳大利亚和以色列的 ST-10 分离株时，发现澳大利亚分离株中 ST-10 更为优势（8 株中的 7 株），而以色列分离株中 ST-10 为 3 株。对本研究中 60 株分离株进行的进化关系分析以及从 pubmlst/mbovis 数据库中检索的 206 株额外分离株进行的 geoBURST 最小生成树（MST）分析均证实，本研究中主要为 ST-10 的中国、以色列和澳大利亚牛分枝杆菌分离株聚类在 CC3 中，与源自美国的分离株聚类在一起。我们的结果表明，ST-10 是牛分枝杆菌种群中的一个新兴克隆。我们假设这种类型的广泛分布是全球牲畜流动的结果。这些发现将有助于进一步了解牛分枝杆菌的全球进化以及针对牛分枝杆菌的新型疫苗的开发。
