【摘要】 目的阐明结核分枝杆菌耐利福平菌株rpoB基因的突变特征。方法对包含81bp的利福平抗药性决定区(rifampicin-resistance determining region,RRDR)的30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。结果18株耐利福平菌株中,除一株发生了513,514位密码子的缺失突变外,其他菌株均发生了单核甘酸替换(单点突变),并且这些突变均发生在rpoB基因的RRDR区内。其中531,526,516位密码子的突变率分别为44.4%,27.8%,16.7%,它们之和为88.9%;12株利福平敏感株中有3株检出了与耐药性有关的基因突变。结论西安地区结核分枝杆菌耐利福平菌株rpoB基因突变以点突变为主,缺失突变则比较少见。最为常见的突变分别位于531位、526位和516位密码子,其中531位密码子的突变率同其他位相比占有明显优势,且531位TCG→TTG突变在rpoB基因所有突变类型中具有最高的突变频率。更多还原

【Abstract】 Aim To clarify the mutation characteristic of rpoB gene of rifampin-resistant clinical Mycobacterium tuberculosis isolated from the patients of Xi′an.Methods PCR products of rpoB gene including 81 bp rifampin-resistance determining region(RRDR) were analyzed by DNA sequencing.Results Amomg 18 rifampin-resistant strains,only one strain was detected deletion mutation in codons 513 and 514 of rpoB gene,others had single nuleotide substitution(point mutation).All mutations occured in the 81 bp RRDR.The summation of mutation rates which occured in codon 531(44.4%),codon 526(27.8%) and codon 516(16.7%) were 88.9%.Among 12 rifampin-susceptible strains,3 strains are gene mutations directly related to rifampin resistance.Conclusion Point mutation is most common in the mutations of rpoB gene,and deletion mutation is rare.Most frequently, the point mutations which occured in codons of 531,526 and 516 of rpoB gene,and the mutation which occured in codons 531 with TCG→TTG were found with the highest frequency in all types of rpoB mutations.更多还原