Fig. 5: McpC contributes to invasion in the gastrointestinal tract.

a Streptomycin pretreated C57BL/6 mice were infected orally with a 1:1 mixture of 10⁶ CFU (oral) or 500 CFU (i.v.) each of either WT and ΔmcpC or WT carrying an empty plasmid (pnull) and ΔmcpC carrying a complementing plasmid (pmcpC). For oral infections, the indicated organ CFU loads of either n = 10 mice (WT pnull:ΔmcpC pmcpC) or n = 20 mice (WT:ΔmcpC), were assessed at 2 d pi. For intravenous infection, the spleen CFU loads of n = 10 mice (WT:ΔmcpC) were assessed at 4 d pi. Each dot represents the CI from a single mouse with the mean shown. Statistical significances were determined by two-way Anova followed by Sudak’s multiple comparisons on log-transformed CFU values for analyzing multiple tissue types in the gastrointestinal tract (WT vs. ΔmcpC in the cecum: p = 0.0001, in the feces: p = 0.0002, in the terminal ileum: p = 0.005; WT pnull:ΔmcpC pmcpC in the cecum: p = 0.5, in the feces: p = 0.3, in the terminal ileum: p = 0.5). For analyzing statistical significance in the spleen, a two-tailed Wilcoxon test was performed on log-transformed CFU values (WT vs. ΔmcpC: p = 0.13). b Ligated jejunal (n = 6 loops from 3 calves) or ileal loops (n = 4 loops from 2 calves) were injected with a 1:1 mixture of 10⁷ CFU total of WT and ΔmcpC, one of which expressed mCherry as indicated. Each dot represents the CI from an individual loop with the mean shown. Tissue samples (gentamicin-treated biopsies), mucus, or luminal fluid were assessed at 2 h pi. Statistical significance was determined by two-way Anova followed by Sudak’s multiple comparisons on log-transformed CFU values (WT vs. ΔmcpC in the jejunal tissue: p = 0.007, in the ileal tissue: p = 0.02, in the jejunal fluid: 0.9, in the ileal fluid: p = 0.9, in the jejunal mucus: p = 0.8, in the ileal mucus: p = 0.9). ns = not significant, *p < 0.05. Source data are provided as a Source Data file.