【摘要】 目的 :探讨结核分支杆菌对乙胺丁醇 (EMB)产生耐药性的分子机制 ,建立直接快速检测结核分支杆菌EMB药物敏感性的实验方法。方法 :采用PCR扩增技术对 1 0株耐乙胺丁醇结核分支杆菌进行PCR扩增 ,扩增产物经纯化后 ,直接在ABI377型全自动测序仪上进行DNA测序分析。结果 :1 0株EMB耐药株的embB基因测序有 7株(70 % )发现点突变 ,其中Met(ATG)→Lle(ATA) 2例 ,Met(ATG)→Lle(ATC) 1例 ,Met(ATG)→Lle(ATT) 2例 ,Met(ATG)→Val(GTG) 2例 ,另外 3株EMB耐药株的embB基因测序未发现突变位点。结论 :embB30 6位氨基酸Met被置换是结核分支杆菌对乙胺丁醇产生耐药性的重要机制 ,测序分析可确认耐药基因的突变位点 ,是快速检测耐乙胺丁醇结核菌的有效方法更多还原

【Abstract】 Aim:To research the molecular mechanism of M.tuberculosis resistance to ethambutol, and to set up a met hod for direct, rapid detection of ethambutol-resistance gene mutations in M.tuberculosis. Methods: The piece of embB gene of 10 M.tuberculosis isolates were produced by polymerase chain reation, and then were purified .The purified products were analyzed by DNA sequencing directly. Results: Seven out of 10(70%) ethambutol-resistance embB genes showed apparent differences from genes of standard strain and the mutation site was at codon 306 of embB. That was 2 Met(ATG)→Lle(ATA),1 Met(ATG)→Lle(ATC),2 Met(ATG)→Lle(ATT), and 2 Met(ATG)→Val(GTG). The other 3 ethambutol-resistance embB genes did not show abnormity. Conclusions: The codon 306 of embB gene mutation might be an important mechanism of M.tuberculosis resistance to ethambutol. DNA squencing could be used as a simple, rapid and reliable diagnostic method for ethambutol-resistant M.tuberculosis.更多还原