An early window of opportunity for A/E microcolony induction in wild-type mice.

<p>(<b>A</b>) Colonic luminal colonization trajectories of the pre-infection strain (red open symbols: circles, 10⁴ CFU Wild type <i>C</i>. <i>rodentium</i> [WT]; squares, 10¹⁰ CFU WT; inverted triangles; 10¹⁰ CFU Δ<i>ler</i> mutant), the super-infection strain (blue filled symbols: circles, 10⁴ CFU WT; squares, 10¹⁰ CFU WT), and total bacteria (pre-infection + super-infection strain; black triangles). Connecting lines connect means; error bars indicate standard deviations. Horizontal dotted lines indicate the lower detection limit. (<b>B</b>) Microcolony formation of superinfection strain after 7 days. N = 6–7 per group, pooled from 3 independent experiments. (<b>C-G</b>) Representative confocal fluorescent microscopy images of distal colon of mice shown in panel B. Grey, F-actin/phalloidin; green, anti-O-antigen Antibody (<i>C</i>. <i>rodentium</i> total); red, mCherry-expressing <i>C</i>. <i>rodentium</i> (pre-infection strain only); Scale bars: 200 μm and 100 μm as indicated; White squares indicate origin of higher-magnification image; *, p < 0.05; **, p < 0.01; ***, P < 0.001; ns, not significant (p ≥ 0.05); statistical test: one-way ANOVA.