结核分枝杆菌katG基因突变的研究

Study on mutations of katG genes in Mycobacterium tuberculosis isoniazid-resistant isolates

探讨编码过氧化氢-过氧化物酶的katG基因突变与结核分枝杆菌异烟肼(INH)耐药性的相关关系。根据结核分枝杆菌GenBank中的katG序列,自行设计特异性寡聚核苷酸引物,采用聚合酶链反应-单链构象多态性(PCR-SSCP)分析和直接测序法(DS)分析结核分枝杆菌中katG基因突变情况。以H37Rv标准株为对照。所有23株敏感菌均未有SSCP结果异常;35株耐药菌中,有2株(5.7％)katG基因扩增阴性,且发生在高度耐药菌中。进一步分析发现,SSCP法突变检出23株(65.7％),测序法突变检出24株(68.6％),符合率为95.8％(23/24)。参照测序法对耐药菌突变序列的分析结果,PCR-SSCP敏感、特异,可快速检测结核分枝杆菌katG耐药基因突变,有利于耐药结核分枝杆菌耐药性的快速检测。

To investigate the relationship between the mutation of the katG gene of the encoded hydrogen oxide peroxidase and isoniazid-resistance in Mycobacterium tuberculosis. The specific oligonucleotide primers of the katG gene was self-designed according to the EMBL:X68081,and katG gene mutations were detected by PCR-SSCP and DS. H37Rv standard isolates used as control. None of SSCP abnormity phenomenon were discovered among 23 sensitive isolates. Among 35 resistant isolates, 2(5.7%) lacked katG gene occurred in those highly INH-resistant isolates; The mutation of 23 (65.7%) isolates were detected with the PCR-SSCP technique and the mutation for 24 isolates was detected with DS technique. The coincidence rate for two techniques is 95.8% (23/24). Refer to the results of gene mutations which were detected with DS technique, PCR-SSCP is a sensitive and specific method for rapid detecting katG gene mutations of M. tuberculosis, and useful in rapid detecting the drug-resistant M. tuberculosis.