青岛地区结核分支杆菌吡嗪酰胺耐药基因pncA的检测

目的 了解青岛地区结核分支杆菌耐吡嗪酰胺（PZA）分离株pncA基因突变的情况，探讨其与耐PZA之间的关系。方法 应用BACTEC-460培养系统对76例结核分支杆菌临床分离株进行结核分支杆菌常规培养和药敏检测，聚合酶链反应-单链构象多态性（PCR-SSCP）技术检测pncA基因的突变。结果 76株结核分支杆菌临床分离株均经PCR扩增出结核分支杆菌复合群保守序列IS6110基因片段，69株扩增出pncA基因的特异序列。后者包括：SSCP泳动异常者18株，其中耐药株13株，敏感株5株；SSCP泳动正常者51株，其中耐药株14株，敏感株37株。结论 青岛地区结核分支杆菌临床分离株耐PZA主要分子机制之一为pncA基因的突变；PCR—SSCP技术能快速准确地检测结核分支杆菌耐PZA基因pncA的突变，可弥补常规药敏试验的不足。

DETECTION OF PYRAZINAMIDE-RESISTANT GENE pncA OF MYCOBACTERIUM TUBERCULOSIS ISOLATES IN QINGDAO AREA

Objective To investigate the mutations of pncA gene in clinical isolates of Mycobacterium tuberculosis and the relationship between pncA gene and pyrazinamide(PZA)-resistance in Qingdao area. Methods From 76 clinical isolates of Mycobacterium tuberculosis,the routine culture and drug susceptibility detection were done by BACTEC-460 system,and the mutations of pncA gene detected by PCR-SSCP. Results Among the 76 isolates,44 strains were PZA-sensitive and 32 PZA-resistant by the BACTEC-460 system.With PCR-SSCP,18 strains displayed abnormal pncA SSCP profile,in which,13 were PZAe-resistant and five PZA-sensitive.Fifty-one strains displayed normal pncA SSCP profile,in which 14 were PZA-resistant and 37 PZA-sensitive. Conclusion Mutation of pncA gene might be one of the major molecular mechanisms in pyrazinamide-resistance of clinical isolates of Mycobacterium tuberculosis.PCR-SSCP appears to be a promising method for rapid detection of pyrazinamide-resistant Mycobacterium tuberculosis,preferable to the routine drug-susceptibility test.