Fig. 5. SpvB promotes the pathogenicity of Salmonella and induces colon cell death in vivo.

A, B C57BL/6 mice were treated with streptomycin 24 h prior to oral infection with the WT or ΔspvB S. Typhimurium strain (1 × 10⁷ CFUs). A Survival curves, n = 10 mice per group. B Body weight changes, n = 10 mice per group. C, D C57BL/6 mice were treated with streptomycin 24 h prior to oral infection with the WT or ΔspvB S. Typhimurium strain (1 × 10⁸ CFUs) and analyzed at 48 h. C Colon length and representative photographs of colons, n = 5 mice per group. D Immunofluorescence staining of colon sections from mice and representative images of TUNEL-positive cells were denoted by arrows, counted ten high-power fields (TUNEL, green; DAPI, blue). Scale bars: 50 μm. Survival curves were analyzed with the log-rank test. Data were analyzed with IBM SPSS Statistics 19 and presented as the mean ± SEM using Student’s t-test. *P < 0.05, **P < 0.005, ***P < 0.001; ns not significant.