FIG. 8.

Chronic infection in models for typhoid fever and colitis. 129Sv/Ev mice were H₂O pretreated (five mice) or streptomycin pretreated (six mice) and then infected intragastrically with 5 × 10⁷ CFU serovar Typhimurium for 20 days. Two mice were streptomycin pretreated and analyzed 20 days post-streptomycin treatment. (A to D) Bacterial loads in the cecal contents (A), mLN (B), liver (C), and spleen (D). Dotted line, limit of detection. (E) Histopathological analysis. HE-stained sections of cecal tissue were scored with respect to edema in the submucosa (black), PMN infiltration (medium gray), reduction in the number of goblet cells (dark gray), and desquamation/erosion/ulceration of the epithelial layer (light gray) (see Materials and Methods). The incidence of cholangitis (expressed as the number of animals with cholangitis/total number of animals per group) is indicated. Scores were plotted as stacked vertical bars.