FIG 1.

The inhibition effect of BZA on M. tuberculosis growth in vitro and in vivo. (A and B) Bacteria were diluted with liquid 7H9 culture medium to an OD of 0.01 and transferred to a 96-well microtiter plate. Bacteria were grown in the presence of 10-fold serially diluted concentrations of BZA. DMSO was added as a negative control. The growth rate of M. smegmatis (A) and M. tuberculosis H37Ra (B) was calculated. (C and D) CFU of H37Ra (C) and H37Rv (D) (MOI = 10:1) treated with BZA (5 μM) is shown. THP-1 macrophages were differentiated by PMA and infected with H37Ra (MOI = 10:1) for 6 h. After washing three times with prewarmed sterile phosphate-buffered saline (PBS) to remove extracellular bacteria, the infected THP-1 cells were treated with or without BZA (5 μM) for another 72 h. Cells were lysed in 0.1% SDS and plated on 7H10 plates. The bactericidal activity of macrophages was assessed by determining CFU of intracellular H37Ra and H37Rv. The data represent means ± standard deviations (SD) for three independent experiments. Values that are significantly different by one-way ANOVA and two-tailed Student’s t test are indicated by asterisks as follows: *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001 (ns, not significant).