Fig 2.

Influence of disruption of bfrA and bfrB on the ability of M. tuberculosis to withstand oxidative stress. Shown is the range of the inhibition zones observed in the presence of various concentrations of cumene hydroperoxide (A) and plumbagin (B). H37Rv ΔbfrA exhibited a significant sensitivity toward both cumene hydroperoxide and plumbagin, although only at higher concentrations, whereas H37Rv ΔbfrB exhibited a significant sensitivity toward cumene hydroperoxide. H37Rv ΔbfrA ΔbfrB exhibited a significantly higher sensitivity to oxidative stress induced by both agents compared to that of the parental strain. The values of zones of inhibition are represented as the means (± standard errors) of three independent samples, and the experiment was repeated three times. *, P < 0.05; **, P < 0.01; ***, P < 0.001 (two-way ANOVA).