结核分枝杆菌链霉素耐药临床分离株rrs基因突变与其耐药水平相关性研究

Mycobacteria tuberculosis streptomycin resistant isolatesrrs gene mutation and its drug resistance level correlation studies

研究武汉地区耐链霉素(SM)结核分枝杆菌的耐药分子机制,进一步研究阐明rrs基因突变与结核分枝杆菌耐链霉素的关系;同时探究武汉地区结核分枝杆菌"北京基因型"菌株的流行趋势,为进一步研究武汉地区耐链霉素菌株rrs基因突变与"北京基因型"的相关性奠定基础。84株结核分枝杆菌中,44株对链霉素耐药,20株耐其它药物,20株对链霉素敏感,采用PCR直接测序法分析链霉素菌株rrs基因突变情况;采用RD105缺失法鉴定84株临床分离菌株中"北京基因型"菌株。结果显示44株SM耐药菌株中,16(36.4%)株检测到rrs基因突变,其中9株1401位点A→G,6株514位点A→C突变,1株1487位点G→A突变;20株耐其它药菌株中1401位点A→G和514位点A→C突变各1株,20株敏感菌株中发现1株1029位点C→T点突变;84株临床分离菌株中有77(91.8%)株"北京基因型"菌株,7株非"北京基因型"菌株。研究表明链霉素耐药菌株rrs基因主要突变位点在514和1401位点,武汉地区"北京基因型"菌株为当地流行的结核分枝杆菌,且SM耐药菌株中突变菌株93.8%(15/16)为"北京基因型","北京基因型"菌株研究及其鉴定是有其科学价值的,值得我们重视。

The research aims to explore the molecular mechanism of drug-resistant mycobacterium tuberculosis resistance to SM in Wuhan area,and elucidate the relationship between rrs gene mutation and mycobacterium tuberculosis resistance to streptomycin; at the same time to reveal the transmission of Beijing genotype strains of mycobacterium tuberculosis in Wuhan,and lay foundation for futher study in the correlation between rrs gene mutation and Beijing genotype in SM-resistant clinical isolates. 84 strains of mycobacterium tuberculosis were obtained,of which 44 were resistant to SM,20 were resistant to other drugs,20 were SM susceptible. Direct sequencing analysis was used to detect rrs genes,RD105 gene deletion was used to identify the Beijing genotype in the 84 clinical isolates. Among 44 SM-resistant isolates,rrs gene mutation was detected in 16（ 36. 4%） isolates,9 took mutation A1401 G,6 took mutation A514C; C1029 T mutation was found in one of 20 sensitive strains; A1401 G and A514 C mutation were found in 20 strains resistant to other drugs; among 84 clinical isolates： 77（ 91. 7%） Beijing genotype strains,7 Beijing genotype strains were found. Our study showed that rrs gene mutation in streptomycin resistant strains mainly happened in 514 and 1401 locus. Beijing genotype was epidemic in Wuhan area and accounted for93. 8%（ 15 /16） in the SM-resistant clinical isolates,suggesting that research and identification of Beijing genotype strains has its scientific value.