Fig. (5).

Hydrogen peroxide susceptibility of wild type and mutant S. Typhimurium ATCC14028 strains lacking the kat genes.. Results are expressed as percent survival after 30 minutes incubation with 17.4 mM hydrogen peroxide at room temperature. The different strains [wt; PF139 (katE::cat katN::kan); PF141 (katE::cat katG::scar); PF132 (katG::cat katN::kan)] were grown in both LSMMG (solid bars) and NG (open bars) conditions. The percent survival was calculated for each strain by dividing the number of CFU/ml obtained after incubation with hydrogen peroxide by the number of CFU/ml obtained after incubation in PBS alone. The results are the average of three experiments and represent mean ± standard errors.