牛结核分枝杆菌临床分离株rpoB、KatG基因突变分析

Characterization and Rapid Detection of Mutations in rpoB,KatG Gene of Clinical Isolates Mycobacterium bovis

为了解牛结核分枝杆菌临床分离菌株对利福平(RFP)、异烟肼(INH)的分子耐药机制,本研究采用噬菌体生物扩增法对分离并鉴定的25株牛结核分枝杆菌进行药敏分析,筛选出9株耐利福平、异烟肼菌株,PCR扩增耐药株的rpoB基因片段(213bp)和KatG基因片段(458bp)并测序。通过对耐药基因的测序分析,5株利福平耐药株的rpoB基因在531位点(RNA聚合酶β-亚基编码基因起始密码子起,下同)、526位点、511位点发生突变,其中有3株rpoB基因531位点发生突变,1株rpoB基因526位点突变;1株rpoB基因在531位点和511位点发生了较为少见的联合突变;4株异烟肼耐药菌株,其中2株在315位点(KatG蛋白编码基因起始密码子起,下同)发生碱基突变,2株在463位点发生碱基突变。

To study on Mycobacterium tuberculosis clinical isolates Molecular resistance mechanism of RFP and INH, this study analysed tuberculosis drug susceptibility of 25 strains Mycobacterium bovis by phage amplified biologically assay. It selected nine-resistant RFP or INH strains, then amplified and sequenced the rpoB gene fragments （213bp） and KatG gene fragments （458bp） of the nine strains. The result showed that 5 RFP resistant strains occurred mutation in 531,526, 511 site of rpoB gene. Three of them occurred in 531 site, one of them occurred in 526 site, and one of them occurred in both 531 and 511 sites which was a relatively rare joint mutation. While two INH resistant strains occurred mutation in 315 site of KatG gene and the other two INH resistant strains occurred in 463 site of KatG gene.