Pyrazinamide resistance among multidrug-resistant tuberculosis clinical isolates in a national referral center of China and its correlations with pncA , rpsA , and panD gene mutations

Abstract Our study was aimed to identify the phenotypic and genotypic pyrazinamide (PZA) resistance features among multidrug-resistant (MDR) isolates in a national tuberculosis (TB) referral center of China. PZA susceptibility test was performed for a total of 142 MDR-TB clinical isolates using the MGIT 960 PZA kits, and the pncA , rpsA , and panD genes were sequenced. Extensively drug-resistant (XDR) and pre-XDR strains had higher PZA resistance rate than that of MDR strains which were still sensitive to fluoroquinolone and aminoglycoside (42.9%, 24/56) (χ2 = 8.922, P = 0.012). No panD mutation was detected among the PZA resistant strains with wild-type pncA and rpsA genes. Our study indicates that PZA-resistant frequency increases with TB drug resistance level; pncA , rpsA , and panD mutations had strong, low, and no correlation with PZA resistance, and rapid molecular assay will facilitate the timely identification of the PZA-sensitive MDR-TB.