Adherent-invasive Escherichia coli Biofilm Formation Assays

Abstract

Patients with Crohn’s disease are abnormally colonized by adherent-invasive Escherichia coli (AIEC) bacteria (Chassaing and Darfeuille-Michaud, 2011). These bacteria are able to adhere to and invade intestinal epithelial cells (IEC), to replicate within macrophages, and were recently described to be able to form biofilms (Martinez-Medina et al., 2009; Chassaing and Darfeuille-Michaud, 2013). The reference strain of adherent-invasive E. coli is the strain LF82, associated with ileal Crohn’s disease (Darfeuille-Michaud et al., 1998). This protocol described basic steps of a biofilm formation assay on I) non-cell-treated polystyrene microtiter plates and on II) paraformaldehyde-fixed I-407 IEC monolayers.