Figure 2. Increased load of commensals in the peripheral organs of infected Il22^−/−mice.

A, The number of total cultivable bacteria in spleen, kidney, liver, lung and feces from Il22^−/− (n=9) and WT mice (n=8) infected with 10⁸ CFU of C. difficile. Bacterial loads were determined on day 0 and 3 post-infection by plating on non-selective BHI. B and C, The concentrations of AST (B) and ALT (C) in sera from Il22^−/− (n=12) and WT mice (n=10) 3 days after C. difficile infection. Results are representative of two independent experiments. D to G Il22^−/− mice were treated with 417 mg/kg ciprofloxacin in the drinking water or left alone (−) after C. difficile infection. D, The numbers of total bacteria, enterobacteria and C. difficile in feces of ciprofloxacin-treated and non-treated control mice (n=7 per group) on day 2 post-infection were determined by quantitative RT-PCR. E, Survival of ciprofloxacin-treated (n=8) and non-treated mice (n=7) infected with C. difficile was monitored for 14 days. No additional deaths were observed beyond 5 days after infection. F, The number of total cultivable bacteria in spleen, kidney, liver and lung from ciprofloxacin-treated (n=9) and non-treated mice (n=8) on day 3 infection with C. difficile. Results are representative of two independent experiments. G, Taxonomic composition of fecal bacteria and cultivable bacterial populations in the liver of ciprofloxacin-treated and non-treated mice day 3 after C. difficile infection (n=3 or 2 per group). Bars indicate means. *, p < 0.05; **, p < 0.01; ****, p<0.0001; n.s., not significant (p > 0.05).