FIG 7.

Mycobacteria lacking cytochrome bd have increased sensitivity to 4-amino-thieno[2,3-d]pyrimidines. (A to C) Either WT M. tuberculosis (Mtb) or M. tuberculosis ΔcydA was incubated in the presence of increasing concentrations of CWHM-728 (A), CWHM-1023 (B), or Q203 (C), and respiration and metabolism were measured using the MABA (n = 3 replicates). (D) WT M. smegmatis (Msm) or M. smegmatis ΔcydA complemented with the empty vector (EV) or with a plasmid harboring cydAB was incubated in the presence of increasing concentrations of CWHM-1023, and respiration and metabolism were measured using the MABA (n = 3 replicates). (A to D) Best-fit curves and IC₅₀ values ± standard deviation (S.D.) were generated using GraphPad Prism software. P values were determined by Student's t test (A to C) or one-way analysis of variance with Tukey’s posttest (D). *, P < 0.05; ****, P < 0.0001; ns, not significant.