The genus Mycobacterium includes a wide range of species of both slow and rapid growth under major pathogens, opportunists, and saprophytes. The number and combination of sigma factors are extremely diversified among various species of Mycobacterium. The comparative genome analysis illustrates that SigC, SigD, SigG, SigH, SigK and SigI are dominant among the pathogens. Evolutionary analysis using Bayesian inference on 16S rRNA and MLST-based phylogeny using 14 housekeeping genes distinctly differentiate the slow-growing Mycobacterium from fast growers and segregate pathogens from opportunists and saprophytes. Based on the similarity coefficient upon the allotment of sigma factors in mycobacterial species through UPGMA dendrogram analysis, it is apparent that the pathogens are grouped separately following the similar trend observed from the evolutionary approach. Predominance of a set of sigma factors particularly the pathogenic Mycobacterium co-exists with the distribution of six well-known virulence factors of Mycobacterium (PhoP, PcaA, FbpA, Mce1B, KatG and PE_PGRS30). The pathogenicity responsible sigma factors elicit close resemblance with few notable characters of the known virulence factors. Thus the analysis renders that the distribution of sigma factors of different species of Mycobacterium can be a potential tool to predict their pathogenicity index.

中文翻译：

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西格玛因子的分布描绘了有毒和无毒分枝杆菌的分离

分枝杆菌属包括多种在主要病原体、机会主义和腐生菌下生长缓慢和快速的物种。西格玛因子的数量和组合在各种分枝杆菌中极为多样化。比较基因组分析表明，SigC、SigD、SigG、SigH、SigK 和 SigI 在病原体中占优势。使用贝叶斯推断对 16S rRNA 和基于 MLST 的系统发育进行的进化分析使用 14 个看家基因明显区分生长缓慢的分枝杆菌和快速生长的分枝杆菌，并将病原体与机会主义者和腐生植物分开。基于通过 UPGMA 树状图分析分枝杆菌物种中西格玛因子分配的相似系数，很明显，按照从进化方法观察到的类似趋势，病原体被分开分组。一组西格玛因子的优势，特别是致病性分枝杆菌与六种众所周知的分枝杆菌毒力因子（PhoP、PcaA、FbpA、Mce1B、KatG 和 PE_PGRS30）的分布共存。引起致病性的 sigma 因子与已知毒力因子的几个显着特征非常相似。因此，该分析表明，不同分枝杆菌种的 sigma 因子的分布可以成为预测其致病性指数的潜在工具。引起致病性的 sigma 因子与已知毒力因子的几个显着特征非常相似。因此，该分析表明，不同分枝杆菌种的 sigma 因子的分布可以成为预测其致病性指数的潜在工具。引起致病性的 sigma 因子与已知毒力因子的几个显着特征非常相似。因此，该分析表明，不同分枝杆菌种的 sigma 因子的分布可以成为预测其致病性指数的潜在工具。