【摘要】 目的　了解结核分枝杆菌耐乙胺丁醇 (EMB)分离株embB基因突变情况 ,研究其应用价值。方法　通过聚合酶链反应 单链构象多态性 (PCR SSCP)、PCR 限制性片段长度多态性 (RFLP)和PCR 直接测序技术分析 10 2株结核分枝杆菌临床分离株embB基因。结果　以H3 7Rv标准株为对照 ,10 2株结核分枝杆菌临床分离株的 16SrDNASSCP电泳图谱均与结核分枝杆菌标准株相同。 41株药物敏感株的embB基因SSCP均泳动正常 ,RFLP和测序分析与对照株相同。 6 1株耐EMB分离株中 ,2 3株 (37.7% )embB基因SSCP泳动异常 ;8株RFLP分析异常 ;测序分析 2 3株均为 30 6位密码子突变 ,其EMBMICs均≥ 2 0 μg/ml,其中 8株为ATG→ATA或ATT突变 ,13株为ATG→GTG或CTG突变 ,后者EMBMICs均≥ 30 μg/ml。 结论　部分结核分枝杆菌耐EMB是由于其embB基因突变所致 ,PCR SSCP技术可能成为测定部分结核分枝杆菌EMB耐药基因型 ,简便、快速的方法更多还原

【Abstract】 Objectives To understand the mutations of embB genes in M. tuberculosis isolates, and to evaluate their clinical value. Method 102 clinical isolates were identified for their mycobacterial species, and then analyzed their embB genes with PCR SSCP, PCR RFLP, and PCR direct sequencing. Results Mycobacterium tuberculosis strain H 37 R v was used as a control. 102 clinical isolates all had the same 16S rDNA SSCP profiles as M. tuberculosis . Forty one drug sensitive isolates had normal embB SSCP and RFLP profiles. Of 61 ethambutol resistant isolates, 23 (37.7%) displayed abnormal embB SSCP profiles. Eight isolates had abnormal RFLP profiles. All embB mutations situated at codon 306, whose EMB MICs were more than 20 μg/ml. Eight isolates had ATG to ATA or ATT mutations at codon 306. Thirty isolates had ATG to GTG or CTG mutations at codon 306, whose EMB MICs were more than 30 μg/ml. Conclusions Ethabutol resistances in some M. tuberculosis isolates were due to mutations on embB genes. PCR SSCP and PCR RFLP method might become a simple and rapid diagnostic test for genotypes of M. tuberculosis ethabutol resistance.更多还原