PncA mutations in pyrazinamide-resistant Mycobacterium tuberculosis isolates / 中华检验医学杂志

ABSTRACT

Objective To evaluate the frequency of pncA gene mutations in pyrazinamide-resistant (PZA-resistant)Mycobacterium tuberculosis(M.TB)isolates.Methods The isolates were tested for PZA susceptibility with absolute concentration method.The pncA gene was amplified and the products were cloned into T-vector,followed with sequencing.Results In all the 36 M.TB isolates,there were 25 PZA-resistant strains and 11 PZA-susceptible strains.Mutations of the pncA gene were found in 10 PZA-resistant isolates,four of which belonging to high PZA-resistant strains.The wild type pncA sequence was present in 3 PZA-susceptible strains, synonymous mutations of pncA gene were detected in two PZA-susceptible strains.Additionally,11 PZA-resistant strains and 2 PZA-susceptible ones showed putative regulatory mutations in the upsteam of pncA gene.Condusions The mutation of the pncA gene can cause the PZA resistance.However.there ale other drug resistance mechanism except this mutation.