[Studies on pncA gene mutations in M. tuberculosis isolates].
OBJECTIVE
To understand the mutations of pncA gene in M. tuberculosis isolates, and to evaluate their clinical value.


METHODS
Analyzing the pncA genes in 74 M. tuberculosis clinical isolates with PCR-SSCP and PCR-AS. M. tuberculosis strain H37Rv was used as control.


RESULTS
32 drug-sensitive isolates all displayed normal pncA SSCP profile. Of 20 non-pyrazinamide-resistant isolates, 4 had abnormal pncA SSCP profile, in which 2 isolates were sequenced, one was TTC-->TTA mutation at codon 58, another was TGG-->CGG mutation at codon 68. Of 22 pyrazinamide-resistant isolates, 10 displayed abnormal pncA SSCP profile, in which 2 isolates sequenced had TTC-->TTA mutation at codon 58.


CONCLUSIONS
The mutation of pncA gene is a pyrazinamide-resistant molecular mechanism in M. tuberculosis. Detecting the mutations of pncA genes might diagnose pyrazinamide resistance rapidly in some M. tuberculosis isolates.
Wu
X
X
Tuberculosis Research Laboratory, 309th Hospital, Beijing 100091, China.
Zhang
J
J
Zhong
M
M
D000581:Amidohydrolases / Q000235:genetics*; D000995:Antitubercular Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics*; D018807:Polymorphism, Single-Stranded Conformational; D011718:Pyrazinamide / Q000494:pharmacology*
D000995:Antitubercular Agents; D011718:Pyrazinamide; D000581:Amidohydrolases; C022490:pyrazinamide deamidase