[Study on the mutations of ahpC genes in M. tuberculosis isoniazid-resistant isolates].
OBJECTIVE
To investigate the mutations of ahpC genes in M. tuberculosis isoniazid-resistant isolates, and to study the correlation between ahpC alterations and isoniazid resistance.


METHODS
Analyzing the ahpC coding sequences and ahpC promoters in 62 M. tuberculosis clinical isolates with PCR-SSCP method. M. tuberculosis strain H37RV was used as control.


RESULTS
The ahpC coding sequences showed normal SSCP profiles in 62 clinical isolates. AhpC promoter mutations were identified in 5 of 12 high isoniazid-resistant strains, and were not altered in 18 low isoniazid-resistant and 32 drug-sensitive isolates.


CONCLUSIONS
The mutation of ahpC coding gene was not correlated with isoniazid-resistant M. tuberculosis isolates. AhpC promoter mutation was a compensatory change in katG-defective and catalase-negative isolates, may be used as a indirect marker for high resistance to isoniazid.
Wu
X
X
Tuberculosis Research Laboratory, 309th Hospital, PLA, Beijing 100091.
Zhang
J
J
Hu
Z
Z
D000995:Antitubercular Agents / Q000494:pharmacology; D004352:Drug Resistance, Microbial / Q000235:genetics*; D005798:Genes, Bacterial; D007538:Isoniazid / Q000494:pharmacology*; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics*; D010544:Peroxidases / Q000235:genetics*; D054464:Peroxiredoxins; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D011401:Promoter Regions, Genetic
D000995:Antitubercular Agents; D010544:Peroxidases; D054464:Peroxiredoxins; D007538:Isoniazid