FIG. 4.

Pathological changes in ceca of 129Sv/Ev mice chronically infected with wild-type serovar Typhimurium. Thin sections (thickness, 5 μm) of cecal tissues of mice from the experiment described in the legend to Fig. 3 were HE stained as described in Materials and Methods. Streptomycin-pretreated 129Sv/Ev mice were infected for 20 days (A to C) or 43 days (D and E). e, edema; L, cecal lumen; ul, ulceration. Bars, 200 μm (A and D) and 100 μm (B, C, and E). Boxed areas are enlarged in the panels on the right.