Fig 7. HilE is required for the intestinal colonization of mice by S. Typhimurium.

Groups of eight streptomycin-pretreated mice were orally inoculated with a mixed bacterial suspension containing an equal amount of CFUs (0.5 x 10⁶) of the WT S. Typhimurium strain and the respective mutant (WT + ΔhilE, WT + ΔhilD or WT + ΔhilE ΔhilD). At 3 days post-infection, CFUs from feces and cecum were counted for each strain and a Competitive Index (CI; CFUs mutant / CFUs WT) was obtained. A CI was also determined for the respective inoculum. Data for each mouse or inoculum were log-transformed and plotted. CIs are indicated as follows: WT/ΔhilE, blue circles; WT/ΔhilD, pink squares; and WT/ΔhilE ΔhilD, green triangles. Bars denote the standard error of the mean for each experimental group. CI of 1.0, represented by a horizontal dotted line, indicates that the two strains (WT and mutant) were present in equivalent numbers.