结核分枝杆菌rpoB基因突变特征的初步探讨

The study of rpoB gene mutation of Mycobacterium tuberculosis

目的了解浙江省耐利福平结核分枝杆菌rpoB基因突变特征。方法对65株临床分离菌株rpoB基因509-631位点分别进行PCR-SSCP检测和DNA序列测定,观察不同耐药株rpoB基因突变的规律。结果耐利福平分离株96.4%(27/28)存在rpoB基因突变,其中526位突变率64.3%(18/28),513位突变率21.4%(6/28),531位突变率7.1%(2/28),529位突变率3.6%(1/28);耐其他抗结核药18.5%(5/27)存在rpoB基因突变,突变位点具有随机性。所有敏感菌株均无突变。结论rpoB基因突变与利福平耐药密切相关,浙江省rpoB基因突变主要以526位突变为主,其次为513位,两者占总数的86%(24/28),而耐其他抗结核药菌株也存在rpoB基因的突变,但没有明显规律,且均对利福平敏感。

Objective To investigate the characteristics of rpoB gene mutation of Mycobacterium tuberculosis in local area. Methods 65 Mycobacterum tuberculosis strains were isolated. The rpoB genes containing codon 509 to codon 631 were detected with PCR-SSCP and gene sequencing. Results The mutation rate of rpoB gene from RFP-resistant strains was 96.4 % （27/28）, which contained 64.3 % （18/28） mutation in codon 526,21.4 % （6/28） in codon 513,7.1% （2/28）in codon 531,3.6 % （1/28）in codon 529. The mutation rate of rpoB gene from RFP-sensifive but other drugs-resistant strains was 18.5 % （5/27）and the mutation site was irregular. None mutation was found in drug-sensitive strains. Conclusion The mutation of rpoB is correlative with RFP resistance. Codon 526 and codon 513 are the most frequent in local area. RpoB mutation is also found in other drug-resistant strains.