High prevalence of Escherichia coli belonging to the B2+D phylogenetic group in inflammatory bowel disease

• Published in: Gut Vol. 56; no. 5; pp. 669 - 675
• Main Authors: Kotlowski, Roman, Bernstein, Charles N, Sepehri, Shadi, Krause, Denis O
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd and British Society of Gastroenterology 01-05-2007; BMJ Publishing Group LTD; BMJ Group
• Subjects: Bacteria; Biopsy; Case-Control Studies; Colitis, Ulcerative - metabolism; Colitis, Ulcerative - microbiology; Colon; Colonoscopy; Crohn Disease - metabolism; Crohn Disease - microbiology; Crohns disease; Crohn’s disease; Deoxyribonucleic acid; DNA; DNA, Bacterial - analysis; E coli; Endoscopy; Enterobacteriaceae; Escherichia coli; Escherichia coli - classification; Escherichia coli - pathogenicity; Escherichia coli Infections - complications; Escherichia coli Infections - microbiology; Humans; IBD; Immune system; Inflammation; Inflammatory Bowel Disease; Inflammatory Bowel Diseases - metabolism; Inflammatory Bowel Diseases - microbiology; Multiculturalism & pluralism; PAI; pathogenicity island; Phylogenetics; Phylogeny; Population; restriction fragment length polymorphism; RFLP; ribosomal intergenic spacer analysis; RISA; serine protease autotransporters; SPATE; ulcerative colitis; Virulence; Virulence Factors - analysis
• ISSN: 0017-5749; 1468-3288
• DOI: 10.1136/gut.2006.099796

Background: It is not clear which species of bacteria may be involved in inflammatory bowel disease (IBD). One way of determining which bacteria might be likely candidates is to use culture-independent methods to identify microorganisms that are present in diseased tissues but not in controls. Aims: (1) To assess the diversity of microbial communities of biopsy tissue using culture-independent methods; (2) to culture the bacteria found in the tissues of patients with IBD but not in the controls; (3) to identify potential virulence factors associated with cultured bacteria. Methods: 84 biopsy specimens were collected from 15 controls, 13 patients with Crohn’s disease (CD) and 19 patients with ulcerative colitis (UC) from a population-based case–control study. Ribosomal intergenic spacer analysis (RISA) was conducted to identify unique DNA bands in tissues from patients with CD and UC that did not appear in controls. Results: RISA followed by DNA sequencing identified unique bands in biopsy specimens from patients with IBD that were classified as Escherichia coli. Targeted culture showed a significantly (p<0.05) higher number of Enterobacteriaceae in specimens from patients with IBD. The B2+D phylogenetic group, serine protease autotransporters (SPATE) and adherence factors were more likely to be associated with tissues from patients with UC and CD than with controls. Conclusions: The abundance of Enterobacteriaceae is 3–4 logs higher in tissues of patients with IBD and the B2+D phylogenetic groups are more prevalent in patients with UC and CD. The B2+D phylogenetic groups are associated with SPATE and adherence factors and may have a significant role in disease aetiology.