title: Mucosal and invading bacteria in patients with inflammatory bowel disease compared with controls.
abstract: BACKGROUND
  Endogenous intestinal bacteria and/or specific bacterial pathogens are suspected of being involved in the pathogenesis of inflammatory bowel diseases (IBD). The aim of this study was to investigate IBD tissues for different bacterial population groups harbouring the mucosal surface and/or invading the mucosa.
  
  
  METHODS
  Tissue sections from surgical resections from the terminal ileum and/or the colon from 24 IBD patients (12 active ulcerative colitis (UC), 12 active Crohn disease (CD)) and 14 non-IBD controls were studied by fluorescent in situ hybridization on a quantifiable basis.
  
  
  RESULTS
  More bacteria were detected on the mucosal surface of IBD patients than on those of non-IBD controls (P < 0.05). Bacterial invasion of the mucosa was evident in 83.3% of colonic specimens from the UC patients, in 55.6% of the ileal and in 25% of the colonic specimens from the CD patients, but no bacteria were detected in the tissues of the controls. Colonic UC specimens were colonized by a variety of organisms, such as bacteria belonging to the gamma subdivision of Proteobacteria, the Enterobacteriaceae, the Bacteroides/Prevotella cluster, the Clostridium histolyticum/Clostridium lituseburense group, the Clostridium coccoides/Eubacterium rectale group, high G + C Gram-positive bacteria, or sulphate-reducing bacteria, while CD samples harboured mainly bacteria belonging to the former three groups.
  
  
  CONCLUSIONS
  Pathogenic events in CD and UC may be associated with different alterations in the mucosal flora of the ileum and colon.
authors.affiliation: German Institute of Human Nutrition (DIFE) Potsdam-Rehbrücke, Dept of Gastrointestinal Microbiology, Bergholz-Rehbrücke. b.kleessen@gmx.de
authors.forename: B
authors.initials: B
authors.lastname: Kleessen
authors.forename: A J
authors.initials: AJ
authors.lastname: Kroesen
authors.forename: H J
authors.initials: HJ
authors.lastname: Buhr
authors.forename: M
authors.initials: M
authors.lastname: Blaut
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000382:microbiology*; D003106:Colon / Q000382:microbiology / Q000473:pathology; D015169:Colony Count, Microbial; D003424:Crohn Disease / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis; D006801:Humans; D007082:Ileum / Q000382:microbiology; D017404:In Situ Hybridization, Fluorescence; D007413:Intestinal Mucosa / Q000382:microbiology* / Q000473:pathology; D008875:Middle Aged; D015345:Oligonucleotide Probes / Q000737:chemistry
chemical_list: D004269:DNA, Bacterial; D015345:Oligonucleotide Probes