Comprehension of epidemiologic information and genomics of Mycobacterium tuberculosis clinical strains causing putative nationwide proliferation

结核分枝杆菌临床分离株的基因分型已用于估计其可能的传播途径。在这项研究中，我们重点研究了在日本广泛地区偶尔检测到的两种基因型结核分枝杆菌，pECT04和pECT07。对临床分离的12株基因型进行基因组测序进行比较分析。结果表明，pECT07分离株的系统发育关系与它们的地理来源无关，表明它们在日本周围的传播途径复杂。与pECT04相反，鉴定出了两个分离株pECT04的许多snp特征。这些结果意味着临床分离株的比较基因组学可以提供结核分枝杆菌传播的深度可追溯性，这是目前的基因分型方法从未实现的。

Genotyping of clinical isolates of Mycobacterium tuberculosis has been used to estimate their putative transmission routes. In this study, we focused on two genotypes of M. tuberculosis, pECT04 and pECT07, detected occasionally from broad areas in Japan. Totally twelve clinical isolates of the genotypes were genomically sequenced for comparative analysis. Results show that phylogenetic relation among pECT07 isolates was not associated with their geographic origins, which suggests their complicated transmission routes around Japan. Contrary to pECT04, many SNPs characteristic to two isolates of pECT04 were identified. These results mean that comparative genomics of clinical isolates can provide deep traceability of transmission of M. tuberculosis that has never achieved with present genotyping methods.