FIG 4.

Histological analysis of infected C57BL/6J mouse colons. (A to C) Mice were infected with either the wild-type (A), ΔcpxRA (B), or ΔcpxRA::cpxRA (C) C. rodentium strain and sacrificed at 12 days postinfection. Hematoxylin- and eosin-stained tissue sections for all mice were observed and photographed by using 2.5× (left) and 10× (right) objectives. Typical results are shown. Bar, 200 μm. (D) Crypt heights in mice infected with the indicated C. rodentium strains (n = 7) were measured. Data shown are the means ± standard errors of the means. Asterisks indicate statistical significance (***, P < 0.001), as determined by a Kruskal-Wallis test followed by Dunn's post hoc analysis. (E) A pathology score was determined for mice infected with the indicated C. rodentium strains (n = 7). Asterisks indicate statistical significance (*, P < 0.05), as determined by analysis of variance followed by Bonferroni's multiple-comparison post hoc analysis.