Pyrazinamide resistance determined by liquid culture at low pH better correlates with genetic mutations in MDR tuberculosis isolates

We detected the pyrazinamide (PZA) susceptibility of Mycobacterium tuberculosis strains in the Bactec MGIT 960 liquid medium with different pH values. Our results demonstrated that PZA resistance determined by liquid culture at pH 5.7 (94.9%) showed better correlation with genetic changes among multidrug-resistant M. tuberculosis isolates (P = 0.001).