FIG 1.

The proliferation of S. Typhimurium in macrophages is not related to intestinal inflammation in streptomycin-pretreated mice. (A) Proliferation rates of the indicated S. Typhimurium mutant strains in RAW cells. The proliferation rate of the S. Typhimurium invA (T1) strain in RAW cells was taken as 100. (B and C) Histopathology of the murine cecum 5 days after infection with the indicated S. Typhimurium mutant strains. Representative images of hematoxylin and eosin-stained cecal sections are shown. Scale bars, 100 μm (B). Histopathology scores were determined by blinded examination of cecal sections. Each bar represents an individual mouse (C). (D) Transcript levels of Ifng, Il6, Tnfa, Kc, and Mip2 in the ceca of mice infected with the indicated S. Typhimurium strains at 5 days after infection measured by qPCR. (E) Numbers of bacteria recovered from the ceca, the mesenteric lymph nodes, and the spleens of mice 5 days after infection. A sample t test (A) and the two-tailed Mann-Whitney U test (B, D, and E) were performed for statistical analysis. Individual data are shown as a scatter plot, and bars indicate the means. Asterisks indicate differences that were statistically significant (P < 0.05). NS, not significant.