InlA enhances, but is not required for colonization of the murine intestines.

<p>Female BALB mice were co-infected at night with a 1∶1 mixture of <i>Lm</i> InlA^m and either wild type (wt) <i>Lm</i> EGDe or <i>inlA</i> deletion mutant (Δ<i>inlA</i>) for a total inoculum of 7–9×10⁸ CFU. The total number of each <i>Listeria</i> strain found in either the ileum or colon was determined at both 16 and 60 hpi. Only the terminal third of the small intestine (approximating the ileum) was harvested because a pilot study showed that the majority of <i>L. monocytogenes</i> colonization occurred in the distal portion of the small intestine (<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003015#ppat.1003015.s003" target="_blank">Fig. S3</a>). Pooled data from three separate experiments are plotted as competitive indices (CI) to show the ratio of either wt/InlA^m or Δ<i>inlA</i>/InlA^m recovered from each individual mouse. The geometric mean for each group was compared to the theoretical value of 1.0 and the fold difference is shown in parentheses above.