91株耐利福平结核分枝杆菌的rpoB基因突变分析

目的分析利福平耐药结核菌株rpoB基因突变特点,探讨DNA序列分析在药敏测定中的意义。方法对101株结核分枝杆菌临床分离株rpoB基因的PCR产物进行测序分析,观察其rpoB基因突变的规律。结果 101株临床分离株中,耐利福平91株,经DNA序列分析有85.71%(78/91)菌株存在rpoB基因突变的突变,主要集中在531位(44.87%)和526位(28.21%),未检测到发生缺失或插入碱基突变的菌株,10株敏感株均无突变。结论 rpoB基因核心突变区发生突变是结核分枝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 the characteristics of mutations on Mycobacterium tuberculosis rpoB gene in Anhui province

Objective To explore the characteristics of rpoB mutations in rifampin-resistant M.tuberculosis clinical isolates from Anhui,and to assess the significance of rpoB gene sequencing in the detection of M.tuberculosis resistance to rifampin.Methods 101 clinical isolates of M.tuberculosis including 91 rifampin-resistant strains and 10 susceptible strains were studied.The fragments(629 bp) of rpoB gene of all of the 101 isolates were amplified and sequenced,which comprised the 81 bp rifampin resistance determination region. Results Of the 101 clinical isolates,78 rifampin-resistant isolates had mutations in the 81 bp region of rpoB gene,and there were no mutations in the susceptible strains.Of them,the mutation incidences of 531-Ser and 526-His were 44.87% and 28.21%,respectively.Conclusion Mutations in the 81 bp hyper-variable region of rpoB are the main reason of M.tuberculosis resistance to rifampin.531-Ser and 526-His are commonest mutation sites.