Ex vivo intestinal adhesion of Escherichia coli LF82 in Crohn's disease.

Adherent-invasive Escherichia coli (AIEC) are reported to inhabit the gut mucosa in Crohn's disease (CD), however, little is known about the importance of host factors for the interplay between AIEC and the human gut. To examine if differences in bacterial adhesion patterns are disease associated, the AIEC-prototype strain LF82 was evaluated for its ability to adhere to ileal and colonic biopsies from CD and healthy controls (HC). Moreover, the efficacy of the non-pathogenic E. coli Nissle 1917 (ECN) in averting LF82 adhesion to ileal mucosa was assessed. Similar numbers of LF82 adhered to biopsies from CD and HC. A significantly greater LF82 attachment to ileal versus colonic mucosa was found in HC (P < 0.01), however, not in CD. ECN did not reduce the adhesion of LF82 to ileal specimens in CD or HC. These results show that enhanced bacterial adhesion ability is unlikely to play any significant role in CD, thus implying that other host protective factors may be impaired in CD. Further, exclusion of LF82 attachment by ECN co-incubation does not appear to represent a relevant treatment regimen.