FIGURE 6.

DksA increases fitness of Salmonella exposed to the NADPH phagocyte oxidase. A and B, C57BL/6 (A) and congenic NADPH phagocyte oxidase-deficient (phox) (B) mice were inoculated intraperitoneally with ∼400 cfu of either wild-type (WT) or dksA-deficient Salmonella. The percent of mice surviving the infection was evaluated over time. The data represent 10 mice/group from two separate experiments. C and D, the anti-Salmonella activity of periodate-elicited peritoneal macrophages isolated from C57BL/6 mice (C) or their congenic phox-deficient mice (D) was evaluated over time. The number of surviving intracellular bacteria was estimated at the indicated times after culture on LB agar plates as described under “Experimental Procedures. ” The data represent the mean percent survival ± S.E. (error bars) of 6–12 independent observations from at least two independent experiments. *, p < 0.05; **, p < 0.01 compared with WT controls.