Pathogenic Escherichia coli in inflammatory bowel diseases

Several different groups have recently reported the presence of pathogenic E. coli associated with ileal and/or colonic mucosa of patients with inflammatory bowel diseases. Given the important role of the gut microflora and enteropathogens in the initiation and perpetuation of intestinal inflammation, important issues now arise. Are these IBD associated E. coli pathogenic? Have they evolved from commensal bacteria? What is their reservoir? Are these bacteria sufficient to drive IBD pathogenesis? Which immunological defects may predispose to colonization by such bacteria? In June 2007, clinicians and basic scientists met in Lille, France with the goal of exchanging ideas and materials on this emerging topic. State-of-the-art lectures given by widely recognized international experts were associated with debates, case discussions and expert opinions. This paper summarizes most data that were exchanged during this day and represents an update on the potential role of pathogenic E. coli in inflammatory bowel diseases.