结核分枝杆菌临床分离RFP耐药株rpoB基因突变研究

目的：研究淮南地区结核病患者临床分离RFP耐药株rpoB基因突变的特点.方法：从110例肺结核患者临床分离株中选取44例利福平耐药株和7例敏感株作rpoB基因的PCR扩增及DNA自动测序.结果：44株RFP耐药株,有43株发现rpoB基因突变,均为点突变,发生率为97.73%;其中531位点24株、526位点13株,两者占rpoB突变率的84.09%;516位突变3株,535位突变1株;另外还发现2株联合突变;耐药株中有1株未发现rpoB基因突变;7株RFP敏感株均未发现突变.结论：rpoB基因核心突变区发生突变是结核分支杆菌对利福平耐药的主要原因,其中531位丝氨酸和526位组氨酸是最常见的突变位点.

Study on mutations in rpoB gene of rifampin-resistant clinically isolated Mycobacterium tuberculosis

Objective：To elucidate the characterization of rpoB mutations in rifampin-resistant clinical Mycobacterium tuberculosis isolates in Huainan district. Methods：The rpoB genes of 44 rifampin- resistant strains and 7 susceptible strains seleceted from 110 clinically isolated Mycobacterium tuberculosis strains of pulmonary tuberculosis patients were amplify by PCR and sequenced. Results：The mutations of rpoB are detected in 43 （97.67 %） of 44 rifampin-resistant strains, which all are point mutations, about 84.09 % ropB gene had mutations in codon 531 or 526, including 24 strains in 531 and 13 strians in 526 ;while 3 mutations were occurred in 516 and 1 mutation was occurred in 535 ;in addition,2 union mutations were detected;there were no mutations in 1 rifampin-resistant strains,neither in 7 susceptible strains. Conclusions： Mutations in the hypervariable region of rpoB are the main reason of Mycobaeterium tuberculosis resistant to rifampin. 531 and 526 are the most common positions of mutations.