<i>C. jejuni</i> colonization along the gastrointestinal tract of IL-10^−/− mice with chronic colitis.

<p>Conventionally colonized 6-months-old IL-10<i>⁻</i>^/<i>−</i> mice with chronic colitis were orally infected with <i>C. jejuni</i> strain ATCC 43431 as described in Methods. (<b>A</b>) At day 14 p.i. <i>C. jejuni</i> densities in distinct compartments of the gastrointestinal tract were determined by quantification of live <i>C. jejuni</i> in luminal samples (CFU, colony forming units; solid circles) taken from stomach, duodenum, ileum, and colon by cultural analysis and compared to wildtype controls (WT, open circles). (<b>B</b>) Furthermore, <i>E. coli</i> loads in luminal colonic samples of <i>C. jejuni</i> infected IL-10<i>⁻</i>^/<i>−</i> mice (IL-10, open circles) were compared to healthy wildtype control animals (WT, open diamonds). (<b>C</b>) A complex molecular analysis of the colonic microbiota composition was assessed in IL-10<i>⁻</i>^/<i>−</i> mice with chronic colitis (IL-10; solid circles) and compared to wildtype control animals (WT; open circles). Main gut bacterial groups were quantified by Real-Time-PCR analyses amplifying bacterial 16S rRNA variable regions and 16S rRNA gene numbers/ng DNA derived from luminal colonic samples: <i>Enterobacteriaceae</i> (EB), Enterococci (EC), Lactic acid bacteria (LB), <i>Bifidobacteria</i> (BIF), <i>Bacteroides/Prevotella</i> spp. (BP), <i>Clostridium leptum</i> group (CLEP), <i>Clostridium coccoides</i> group (CLOCC), Mouse intestinal bacteroidetes (MIB), and total eubacterial load (TL). Numbers of animals harboring <i>C. jejuni</i> or <i>E. coli</i> out of the total number of analyzed animals are given in parentheses. Medians (black bars) and significance levels (<i>P</i>-values) determined by Mann-Whitney-U test are indicated. Data shown were pooled from at least three independent experiments.