结核分枝杆菌耐链霉素和乙胺丁醇分子机制的研究

目的:研究结核分枝杆菌耐链霉素和乙胺丁醇的rpsL和emb B基因突变情况,探讨耐药基因突变与耐药性的关系。方法:通过传统药敏实验和聚合酶链反应(PCR)--单链构象多态性(SSCP)技术初步鉴定62株临床分离株的药敏和rps L、emb B基因。结果:与结核菌标准株H37Rv对照,分析30例TB菌耐链霉素(SM)的rps L基因,发现其突变率为70.0%(21/30),分析29例耐乙胺丁醇(EMB)的emb B基因,该基因的突变率为65.5%(19/29)。结论:部分结核分枝杆菌耐SM和EMB是由于其rps L、emb B基因突变所致,PCR-SSCP银染技术可能成为测定部分结核分枝杆菌耐药的简便、快速的方法。

Studies on molecular mechanism of streptomycin and ethambutol resistance in mycobacterium tuberculosis

Objective:To study the mutation ofrps L and emb B genes in mycobacterium tuberculosis isolates,and investigate the relationship between drug-resistance gene mutations and drug-resistance in mycobacterium tuberculosis.Methods:The drug-sensitivity of 62 clinical isolates of mycobacterium species were identified by the traditional method,and then the mutation of their emb B and rps L genes were analyzed with PCR-SSCP.Mycobacterium tuberculosis strain H37RV was used as a control.Results:The mutational frequen- cy of rps L gene in 30 SM-resistant mycobacterium tuberculosis was 70.0%(21/30).The mutational frequency of emb B gene in 29 EMB-resistant isolates was 65.5%(19/29).Conclusion:SM and EMB resistances were due to mutations of rps L and emb B genes in some mycobacterium tuberculosis isolates.PCR-SSCP method might become a simple and rapid diagnostic test for genotypes of SM and EMB resistant mycobacterium tuberculosis.