Figure 1. Intestinal colonization.
Intestinal competition tests were performed in streptomycin-pre-treated CD1 mice. Competitive indexes (CIs) are given for day 1 and day 7 post-inoculation. The CI index is a ratio of ratios, in which the ratio between resistant (TN03) and sensitive (K-12 MG1655, IAI1 or ED1a) strains at post-inoculation time points is divided by this same ratio at the initial inoculation time. Horizontal bars represent median log10 CI ratios and compared to a ratio of null effect (0, that is log10 1.0) using a Wilcoxon signed-rank test.