Fig 7. T6SS contributes to EHEC virulence in mouse model.

(A) ΔT6SS has lower virulence in mice model compared with the WT. The streptomycin pre-treated BALB/c mice were intragastrically infected with the WT or its derived mutants at the inoculation of 10¹⁰ CFU. The percentage of surviving animals (8 mice per group) on each day was calculated. ***, P<0.001, Log-rank analysis. (B) Body weight changes of BALB/c mice infected by the WT, ΔT6SS or ΔkatN. The average body weight change percentage of surviving animals (8 mice per group) on each day was calculated. Error bars represented SD from at least three independent experiments. ***, P<0.001; ns, Not significant, ANOVA analysis. (C) The colonization of the WT, ΔT6SS or ΔkatN in mice gut. At the indicated times, fecal samples were collected, homogenized, diluted and plated on SMAC agar plates to determine the numbers of the WT or its derived mutants. The log₁₀ means of CFU per gram of feces for each group of 8 mice are presented for each time point. Error bars represented SD from at least three independent experiments. ***, P<0.001; ns, Not significant, ANOVA analysis.