Fig. 5: ETEC disrupts in vivo formation of small intestinal microvilli.
Timeline at the top depicts the challenge with ETEC or control nontoxigenic isolate or sham (PBS) challenge. a Quantitative PCR results for genes involved in brush border development in small intestinal samples obtained from infant mice (n = 9/group) 7 days after challenge with toxigenic ETEC (jf876), nontoxigenic ETEC (jf4763, LT−/ST−) PBS controls. Comparisons between data represent ANOVA, Kruskal–Wallis testing where ***p ≤ 0.001, **p ≤ 0.01, and *p ≤ 0.05. b Immunofluorescence images of small intestinal sections showing villin expression (blue), and nuclei (white). c Mean villin fluorescence intensity normalized per enterocyte (n = 4 mice/group) ****p ≤ 0.0001 by Mann–Whitney (two-tailed) nonparametric comparisons. d Representative transmission electron microscopy (TEM) images of the small intestinal brush border from mice challenged with toxin-negative (∆, left) and toxigenic ETEC (wt, right). e Microvillus length ****p ≤ 0.0001 by Mann–Whitney (two-tailed) nonparametric comparisons. Data represent geometric mean length from n = 5 mice per group in three independent experiments. f TEM images from mice challenged with jf570 (eltA::KmR), sham PBS controls, or mice challenged with wild-type ETEC. g Length of microvilli (dashed horizontal lines represent geometric means). ****p < 0.0001 by Kruskal–Wallis.
