Fig. 1

M. tuberculosis napM is induced by various antibiotics and affects mycobacterial growth. a napM was induced by various anti-TB antibiotics in M. tuberculosis. qRT-PCR assays were used to determine the relative expression level of napM in M. tuberculosis upon induction by various anti-TB antibiotics. M. tuberculosis was exposed to rifampicin, kanamycin, ethambutol, and isoniazid. napM expression was normalized by invariant transcript sigA gene. Bars indicate the means ± standard errors calculated from three independent biological experiments. The P values of the results (<0.05, <0.01, and <0.001) are indicated by asterisks (*), double asterisks (**), and triple asterisks (***), respectively. Two-tailed P values are RFP 0.0279, KAN 0.0024, EMB 0.0001, and INH 0.0062 when compared to the no-drug control. b Both napM deletion and napM overexpression inhibited the growth of M. tuberculosis H37Ra. Bacterial counts were determined at two representative time points, 7 and 14 days. Symbols represent each biological replicate and bars indicate means ± standard errors calculated from three independent biological experiments. The P values of the results (<0.05, <0.01, and <0.001) are indicated by asterisks (*), double asterisks (**), and triple asterisks (***), respectively. Two-tailed P values are 0.0022 for dnaA overexpression, 0.0043 for napM overexpression, and 0.0041 for napM-deleted at 7 days, and P values are 0.0003 for dnaA overexpression, 0.0028 for napM overexpression, and 0.0007 for napM-deleted at 14 days when compared to the control empty vector. qRT-PCR, quantitative real-time PCR