Fig 7. Assessment of the protective efficacy of SinH-based vaccines against ExPEC colonization in the GI tract.

(A) The vaccination scheme was used in the murine model of gastrointestinal (GI) tract colonization. BALB/c, 6 weeks old, female mice were subcutaneously immunized with SinH-based antigens (SinH-3, SinH-123, N = 18) or GST alone (N = 18) and inoculated with a gavage of 10⁹ CFU of ExPEC ST131 strains (JJ1886, JJ2547, JJ2050). Feces samples were collected and plated to determine bacteria levels. (B) Box-and-whisker plots of the bacterial levels (CFU/ml) in combining the counts from all ExPEC strains (JJ1886, JJ2547, JJ2050) (C) or the bacterial levels (CFU/ml) of each ExPEC strain in feces. (D) The vaccination scheme was used in the murine model of gastrointestinal (GI) tract colonization in immunosuppressed mice. BALB/c, 6 weeks old, female mice were subcutaneously immunized with SinH-based antigens (SinH-3, SinH-123, N = 18) or GST alone (N = 18) and inoculated with a gavage of 10⁹ CFU of ExPEC ST131 strains (JJ1886, JJ2547, JJ2050). And then, mice were treated with the chemotherapeutic agent Cytoxan (CTX) on alternate days. After three times injections, feces were harvested and plated to determine bacteria levels in immunosuppressed mice. (E) Box-and-whisker plots of the bacterial levels (CFU/ml) in combining the counts from all ExPEC strains (JJ1886, JJ2547, JJ2050) (F) or the bacterial levels (CFU/ml) of each ExPEC strain in immunosuppressed mice feces. Error bars indicate the median with 95% confidence interval (CI). Significant was determined by the Kruskal-Wallis analysis of variance (ANOVA) with Dunn’s multiple comparisons correction. Symbols represent data of individual mice. One star (*) P < 0.05, two stars (**) P < 0.01, three stars (***) P < 0.001, four stars (****) P < 0.0001. The schematic diagrams were made in BioRender. The Box-and-whisker plots were exported from Graphpad Prism 9 and annotated using BioRender.