title: Alterations of the Ileal and Colonic Mucosal Microbiota in Canine Chronic Enteropathies.
abstract: BACKGROUND
  The intestinal microbiota is increasingly linked to the pathogenesis of chronic enteropathies (CE) in dogs. While imbalances in duodenal and fecal microbial communities have been associated with mucosal inflammation, relatively little is known about alterations in mucosal bacteria seen with CE involving the ileum and colon.
  
  
  OBJECTIVE
  To investigate the composition and spatial organization of mucosal microbiota in dogs with CE and controls.
  
  
  METHODS
  Tissue sections from endoscopic biopsies of the ileum and colon from 19 dogs with inflammatory bowel disease (IBD), 6 dogs with granulomatous colitis (GC), 12 dogs with intestinal neoplasia, and 15 controls were studied by fluorescence in situ hybridization (FISH) on a quantifiable basis.
  
  
  RESULTS
  The ileal and colonic mucosa of healthy dogs and dogs with CE is predominantly colonized by bacteria localized to free and adherent mucus compartments. CE dogs harbored more (P < 0.05) mucosal bacteria belonging to the Clostridium-coccoides/Eubacterium rectale group, Bacteroides, Enterobacteriaceae, and Escherichia coli versus controls. Within the CE group, IBD dogs had increased (P < 0.05) Enterobacteriaceae and E. coli bacteria attached onto surface epithelia or invading within the intestinal mucosa. Bacterial invasion with E. coli was observed in the ileal and colonic mucosa of dogs with GC (P < 0.05). Dogs with intestinal neoplasia had increased (P < 0.05) adherent (total bacteria, Enterobacteriaceae, E. coli) and invasive (Enterobacteriaceae, E. coli, and Bacteroides) bacteria in biopsy specimens. Increased numbers of total bacteria adherent to the colonic mucosa were associated with clinical disease severity in IBD dogs (P < 0.05).
  
  
  CONCLUSIONS
  Pathogenic events in canine CE are associated with different populations of the ileal and colonic mucosal microbiota.
authors: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors: Eric
authors: E
authors: Cassmann
authors: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors: Robin
authors: R
authors: White
authors: USDA-ARS, Ames, Iowa, United States of America.
authors: Todd
authors: T
authors: Atherly
authors: Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors: Chong
authors: C
authors: Wang
authors: Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors: Yaxuan
authors: Y
authors: Sun
authors: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors: Samir
authors: S
authors: Khoda
authors: Department of Genetics, Development & Cell Biology, College of Liberal Arts and Sciences, Iowa State University, Ames, Iowa, United States of America.
authors: Curtis
authors: C
authors: Mosher
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors: Mark
authors: M
authors: Ackermann
authors: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
authors: Albert
authors: A
authors: Jergens
mesh_terms: D000818:Animals; D058491:Bacterial Load; D001706:Biopsy; D016022:Case-Control Studies; D002908:Chronic Disease; D003106:Colon / Q000382:microbiology* / Q000473:pathology; D004283:Dog Diseases / Q000175:diagnosis / Q000382:microbiology* / Q000473:pathology; D004285:Dogs; D020776:Endoscopes, Gastrointestinal; D000069196:Gastrointestinal Microbiome; D007082:Ileum / Q000382:microbiology* / Q000473:pathology; D017404:In Situ Hybridization, Fluorescence; D007410:Intestinal Diseases / Q000662:veterinary*; D007413:Intestinal Mucosa / Q000382:microbiology* / Q000473:pathology; D012720:Severity of Illness Index