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

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.