95例耐多药结核菌株rpoB基因突变的分子特征

Molecular characteristics of rpoB gene of 95 multidrug-resistant Mycobacterium tuberculosis isolates

目的:探讨广东地区MDR-TB菌株rpoB基因突变的分子特征。方法:对95例MDR-TB菌株rpoB基因453-564位密码子片段进行PCR-直接测序。结果:95例MDR-TB菌株rpoB基因突变率91.58%。86例为点突变,1例插入突变,未发现缺失。常见位点为531(63.22%)、526(20.69%)、516(9.20%)。其中:单位点突变69例(80.23%),双位点突变16例(18.60%),三位点突变1例(1.17%)。511位点突变常同时伴有其他位点突变(57.14%)。结论:主要突变位点与国内外报道基本相同,但各位点所占比例具有地域差异;联合突变率较高,占19.54%。512位点插入(AGGAGC)突变可能为新突变类型。

Objective To explore the molecular characteristics of rpoB gene of multidrug-resistant Mycobacterium tuberculosis（MDR-TB） isolates in Guangdong.Methods The codon from 453 to 564 in rpoB gene of 95 MDR-TB isolates was sequenced by PCR.Results The mutation rate of rpoB gene of 95 MDR-TB isolates was 91.58%,86 strains were point mutations,one strain was insertion mutation,there wasn＇t deletion mutation found.The most frequent mutations were in codon 531（63.22%）,526（20.69%）,and 516（9.20%）.Among the mutation strains,69 were single-site mutation（80.23%）,16 were double-site mutations（18.60%）,1 was tri-site mutation（1.17%）.About 57.14% of 511 site mutations were accompanied by other site mutations.Conclusions The major mutation sites of MDR-TB in Guangdong were similar to the results of domestic and international reports,but the proportions of each mutation form had regional differences.High combinative mutation rate（19.54%） and a new insertion form（512,AGGAGC） were found in this study.