山东省耐利福平结核分枝杆菌rpoB基因突变的研究

RpoB gene mutations of rifampin?resistant Mycobacterium tuberculosis in Shandong Province

目的分析山东省利福平耐药结核菌株rpoB基因突变特点。方法本研究为回顾性调查,135株样本分别取自1997、2000及2003年的流行病学调查和医院的临床样本。采用PCR直接基因测序法分析rpoB基因突变。结果135株结核菌中,60株为利福平耐药菌株,其中55株(91.7%)rpoB基因的利福平耐药决定区(RRDR)有突变。突变频率依次为密码子531(60.0%),526(29.1%)和516(7.3%)。1株耐药菌同时发生了少见的3个密码子(511,515,518)的多核苷酸突变。75株敏感菌株中,仅3株(4.0%)有突变,均发生在密码子533,包括一个新发现的突变基因型CTG(Leu)→ATG(Met)。结论来自山东省结核菌中,利福平耐药表型与rpoB基因突变的符合率为94.1%,并提示密码子533突变与利福平耐药表型相关性较低。

Objective To investigate gene mutations in the rifampin （RIF） resistance determining region （RRDR） of rpoB gene in Mycobacterium tuberculosis （MTB） isolates from Shandong Province, China. Method60 RIF-resistant and 75 RIF-susceptible MTB isolates collected from over 30 counties of Shandong Province in 1997, 2000, and 2003 were analyzed by direct DNA sequencing. Results Fifty five （91.7%） of 60 RIF - resistant isolates were found missense mutations in RRDR of rpoB gene. The most common mutations occurred at codon 531 （60.0%）, 526 （29.1%） and 516 （7.3%） respectively. One isolate presented multiple mutations at codons 511, 515, 518 simultaneously. Only 3 （4.0%） of 75 RIF- susceptible isolates showed mutations at codon 533 with one novel mutation type （CTG→ATG）. Conclusion The agreement rate between RRDR mutations of rpoB gene and RIF resistance among 135 MTB isolates from Shandong Province is 94.1% （127/135）. Mutations at codon 533 were not associated with RIF resistance.