[Studies on mutation of isoniazid resistant genes in M. tuberculosis].
OBJECTIVE
To understand mutation of isoniazid-resistant genes in M. tuberculosis clinical isolates, and to develop the method for rapid detection of drug resistance.


METHODS
Analyzing the katG genes in 30 M. tuberculosis clinical isolates with PCR-SSCP(single stranded conformation polymorphism) and PCR-DS (direct sequencing) techinques.


RESULTS
With the reference of M. tuberculosis strain H37 Rv was used as control, all isoniazid-sensitive isolates and 4 isoniazid-resistant isolates displayed ab normal PCR-SSCP and PCR-DS patterns. But of 12 isoniazid-resistant isolates, 4(33.4%) isolates displayed abnormal katG PCR-SSCP pattern, 8 (46.7%) isolates displayed abnormal katG PCR-SSCP pattern, 5(41.7%) isolates were missense mutation at codon 94, 3(25%) isolates were cosense mutation at codon 96.


CONCLUSIONS
Resistance to isoniazid in most M. tuberculosis isolates is due to the mutations on katG genes. PCR-SSCP techniques could be used as a method for rapid detection of isoniazid-resistance in M. tuberculosis.
Yao
M H
MH
Department of Microbiology, Xiangya School of Medicine, Central South University, Changsha 410078, China.
Lou
Y H
YH
D004352:Drug Resistance, Microbial / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology*; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics*; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational
D007538:Isoniazid