FIG 6.

Increased virulence of C. rodentium ΔuvrY strain. Susceptible mice were orally gavaged with 2 × 10⁸ to 3 × 10⁸ CFU of the C. rodentium wild-type or ΔuvrY strain. (A) Fecal bacterial burden was assessed at days 3 and 6 postinfection. The data are pooled from two experiments (day 3) and 3 experiments (day 6) with 4 to 5 mice per group per experiment. (B) Mesenteric lymph node bacterial burden was assessed at day 6 postinfection by plating on MacConkey agar and enumerating CFU. The data are pooled from two experiments with 4 mice per group per experiment. A Mann-Whitney test was used to determine statistical significance (*, P < 0.05). (C) Localization of C. rodentium wild type and ΔuvrY strains in distal colon samples of day 6 infected susceptible mice. Sections were stained with DAPI (blue) and anti-Citrobacter LPS (green). Panels on the right show a zoomed-in view of the boxed areas in the panels on the left. Scale bars, 100 μm.