<i>E</i>. <i>coli</i> AfaE-III shows improved mucosal colonization and induces CD105 expression.

<p><i>(A)</i> Wild-type or CEAtg female mice were infected with <i>E</i>. <i>coli</i> AfaE-III or <i>E</i>. <i>coli</i> ΔAfaE-III. 24 h later, bacteria were re-isolated. Each data point in the graph reflects the number of bacteria re-isolated from an individual animal (n = 10). Data were compiled from two independent experiments. The median for each experimental group of animals is indicated by a line; numbers of recovered bacteria were compared by Mann-Whitney U-test and highly significant differences (p<0.001) are indicated by ***. <i>(B</i>, <i>C)</i> Animals were infected as in (A) and genital tracts were excised, fixed and frozen. <i>(B)</i> Cryosections of genital tracts were co-stained with rabbit antibodies against <i>E</i>. <i>coli</i> (green) and a mouse monoclonal antibody against CEA. Cell nuclei were visualized by Hoechst (blue). Numerous <i>E</i>. <i>coli</i> AfaE-III can be detected in close association with the CEA-positive epithelium (arrowhead), whereas non-CEACAM binding <i>E</i>. <i>coli</i> are rarely observed. (C) Cryosections were co-stained with rabbit antibodies against <i>E</i>. <i>coli</i> (green) and a rat monoclonal antibody against murine CD105 (red). Cell nuclei were visualized by Hoechst (blue). Strong local expression of CD105 can be observed on the mucosal surface of CEAtg mice upon association with <i>E</i>. <i>coli</i> AfaE-III (arrowhead). Pictures in B) and C) are representative for three independent biological replicates.