Fig. 6.

Partial inhibition of biotin synthesis increases susceptibility of Mtb to rifampicin in mice. (A) Susceptibilities of the Mtb H37Rv strain and the Mtb mutant bioA TetON-1 strain to rifampicin in biotin-free medium with and without atc. (B) Number of CFU isolated from the lungs of mice infected with the bioA TetON-1 Mtb strain. Mice were fed either doxycycline-containing (blue and purple) or doxycycline-free (gray and red) chow throughout the experiment. Rifampicin was administered 3 weeks after initial infection to one group of mice that received doxycycline (purple) and one group that had not received doxycycline (red). All samples were collected at 4 or 8 weeks after treatment with rifampicin was initiated. (C) Number of CFU isolated from the spleens of mice described in (B). Data in (B) and (C) are for n = 8 mice for each time point. Data are means ± SEM (*P < 0.05, Mann-Whitney test).