Characterization of the epithelial response to EPEC infection <i>in vivo</i>.

<p><b>(A)</b> Heat map showing the intestinal epithelial gene expression in small intestinal tissue of uninfected mice (uninf.) as well as at day 8 p.i. with WT EPEC or <i>escV</i> mutant (n = 4–6 from at least 2 litters). A selection of the most significantly up-regulated genes following WT EPEC infection are shown (p-value = 0.02; q-value = 0.22). <b>(B)</b> Clusters of orthologous group (COG) analysis of the genes shown in <b>(A)</b>. <b>(C-D)</b> 1-day-old mice were orally infected with WT EPEC, <i>escV</i> mutant, <i>bfpA</i> mutant, <i>escV</i>/<i>bfpA</i> double mutant EPEC, a murine commensal <i>E</i>. <i>coli</i> strain or left untreated. IEC were isolated from the small intestinal tissue at 8 days p.i. and the expression levels of <b>(C)</b> <i>saa3</i> and <b>(D)</b> <i>cpn2</i> were determined by quantitative RT-PCR and normalized to the values obtained for the housekeeping gene <i>hprt</i> (n = 4–16 from at least 2 litters; median). Kruskal-Wallis ANOVA with Dunn’s multiple comparison post-test (C-D). ns, p>0.05; **, p<0.01; ***, p<0.001.