FIG. 7.

Quantitative analysis of the intestinal microbiota after 7 days of infection with 10⁷ CFU S. enterica serovar Typhimurium. Mice were inoculated perorally with 10⁷ CFU S. enterica serovar Typhimurium and sacrificed after 7 days. The intestinal tract was removed and divided into the DSI, cecum, and LI. Bacterial genomic DNA was isolated from each segment, and qPCR analysis was performed to determine the abundance of specific commensal bacterial groups in the DSI (a), cecum (b), and LI (c). White bars represent uninfected controls. Black bars represent Salmonella-infected mice. Salmonella infection did affect bacterial counts in the cecum (P < 0.005) and the LI (P < 0.05), and the effects were not uniform across groups. Asterisks represent the post hoc t test for the designated groups (P < 0.005). Salmonella infection did not appear to affect the bacterial counts in the small intestine (P > 0.05). BT, below the detection threshold of qPCR. Erec, Eubacterium rectale/Clostridium coccoides; Lact, Lactobacillus sp.; Bact, Bacteroides sp.; MIB, mouse intestinal Bacteroides; Sfb, segmented filamentous bacteria; Ent, Enterobacteriaceae; C. perf, Clostridium perfringens; Salm, S. enterica serovar Typhimurium.