FIG. 7.

The B. abortus ahpCD katE mutant KK9 exhibits attenuation in IFN-γ-stimulated cultured murine peritoneal macrophages, and this attenuation is not alleviated by the addition of inhibitors of the oxidative and nitrosative bursts of the host phagocytes. The intracellular survival and replication patterns of B. abortus 2308 and the isogenic ahpCD katE double mutant KK9 in IFN-γ-treated cultured resident peritoneal macrophages from BALB/c mice with or without the addition of the NADPH oxidase inhibitor apocynin and iNOS inhibitor L-NMMA are shown. The data presented are means and standard deviations obtained for each bacterial strain from three separate wells of cultured macrophages at each experimental time point in a single experiment. The data presented here are representative of multiple (≥3) experiments performed from which equivalent results and statistical trends were obtained. Statistical significance (P ≤ 0.05) as determined by the Student two-tailed t test for the comparison of 2308 versus KK9 is represented by an asterisk (*).