Time course of <i>C. jejuni</i> colonization in adult mice with increased <i>E. coli</i> loads.

<p>In conventionally colonized 3-months-old adult mice intestinal <i>E. coli</i> loads were raised up to 10⁸ bacteria per gram feces by adding live <i>E. coli</i> into the drinking water (+ <i>E. coli</i>) as described in Methods. Mice were orally infected with <i>C. jejuni</i> strain ATCC 43431 (<b>A</b>) or B2 (<b>B</b>). Kinetic analyses of pathogen densities were performed by quantification of live <i>C. jejuni</i> in fecal samples derived from mice with elevated (Ec; solid circles) or normal (N; open circles) <i>E. coli</i> loads by cultural analysis (CFU, colony forming units) until day 12 p.i. (<b>C</b>) <i>C. jejuni</i> B2 densities in distinct compartments of the gastrointestinal tract were determined in luminal samples taken from stomach, duodenum, ileum, and colon of mice with elevated (Ec; solid circles) or normal (N; open circles) <i>E. coli</i> loads at day 12 p.i. Numbers of animals harboring <i>C. jejuni</i> out of the total number of analyzed animals are given in parentheses. Days post infection, medians (black bars) and levels of significance (<i>P</i>-values) as compared to the respective group (determined by Mann-Whitney-U test) are indicated. Data shown are pooled from at least three independent experiments.