FIG. 5.

Streptomycin administration prior to infection with Salmonella enhances the extent and degree of ileal inflammation in mice. Hematoxylin- and eosin-stained ileum was obtained from mice pretreated with streptomycin and infected with Salmonella. (A) Necrosis of ileal villi accompanied by focally extensive infiltration of lamina propria by large numbers of polymorphonuclear neutrophils extending along the base of intestinal crypts. Magnification, ×12. (B) Infiltration of villous lamina propria by large numbers of polymorphonuclear neutrophils with segmental sloughing of intestinal epithelial cells. Magnification, ×20. (C) Infiltration of ileal Peyer's patch subepithelial dome area by large numbers of polymorphonuclear neutrophils (asterisk) together with focal disruption of the follicle-associated epithelium (arrowhead) and transepithelial migration of neutrophils. Magnification, ×20.