title: Pyrazinamide resistance associated with pncA gene mutation in Mycobacterium tuberculosis in Japan.
abstract: Thirty Japanese clinical isolates of Mycobacterium tuberculosis were analysed by pyrazinamide susceptibility testing and pyrazinamidase assay, as well as polymerase chain reaction for single-strand conformational polymorphism and direct sequencing of the gene encoding pyrazinamidase (pncA). All sensitive isolates showed pyrazinamidase activity and a wild-type pncA gene, but three resistant isolates had pncA gene mutations and lacked pyrazinamidase activity. The latter isolates showed a minimum inhibitory concentration of at least 100 mg/l by the 7H10 agar proportion method and 400 mg/l by the 7H9 liquid medium method. Isolate 28 showed T-to-C change at position 11, leading to Leu4 --> Ser substitution; isolate 29 had an 8-bp deletion from position 382; and isolate 30 had A-to-C change at position 29, leading to Gln10 --> Pro substitution. The deletion has not been described previously. This is the first demonstration of pncA gene mutations in PZA-resistant M. tuberculosis strains isolated from Japanese patients.
authors: Division of Laboratory Diagnosis, Sapporo Medical University School of Medicine, Japan.
authors: T
authors: T
authors: Endoh
authors: A
authors: A
authors: Yagihashi
authors: N
authors: N
authors: Uehara
authors: D
authors: D
authors: Kobayashi
authors: N
authors: N
authors: Tsuji
authors: M
authors: M
authors: Nakamura
authors: S
authors: S
authors: Hayashi
authors: N
authors: N
authors: Fujii
authors: N
authors: N
authors: Watanabe
mesh_terms: D000581:Amidohydrolases / Q000235:genetics*; D000995:Antitubercular Agents / Q000494:pharmacology*; D004252:DNA Mutational Analysis; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance / Q000235:genetics; D006801:Humans; D007564:Japan; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011718:Pyrazinamide / Q000494:pharmacology*
chemical_list: D000995:Antitubercular Agents; D017931:DNA Primers; D004269:DNA, Bacterial; D011718:Pyrazinamide; D000581:Amidohydrolases; C022490:pyrazinamide deamidase