title: Adherent and invasive Escherichia coli is associated with granulomatous colitis in boxer dogs.
abstract: The mucosa-associated microflora is increasingly considered to play a pivotal role in the pathogenesis of inflammatory bowel disease. This study explored the possibility that an abnormal mucosal flora is involved in the etiopathogenesis of granulomatous colitis of Boxer dogs (GCB). Colonic biopsy samples from affected dogs (n = 13) and controls (n = 38) were examined by fluorescent in situ hybridization (FISH) with a eubacterial 16S rRNA probe. Culture, 16S ribosomal DNA sequencing, and histochemistry were used to guide subsequent FISH. GCB-associated Escherichia coli isolates were evaluated for their ability to invade and persist in cultured epithelial cells and macrophages as well as for serotype, phylogenetic group, genome size, overall genotype, and presence of virulence genes. Intramucosal gram-negative coccobacilli were present in 100% of GCB samples but not controls. Invasive bacteria hybridized with FISH probes to E. coli. Three of four GCB-associated E. coli isolates adhered to, invaded, and replicated within cultured epithelial cells. Invasion triggered a "splash"-type response, was decreased by cytochalasin D, genistein, colchicine, and wortmannin, and paralleled the behavior of the Crohn's disease-associated strain E. coli LF 82. GCB E. coli and LF 82 were diverse in serotype and overall genotype but similar in phylogeny (B2 and D), in virulence gene profiles (fyuA, irp1, irp2, chuA, fepC, ibeA, kpsMII, iss), in having a larger genome size than commensal E. coli, and in the presence of novel multilocus sequence types. We conclude that GCB is associated with selective intramucosal colonization by E. coli. E. coli strains associated with GCB and Crohn's disease have an adherent and invasive phenotype and novel multilocus sequence types and resemble E. coli associated with extraintestinal disease in phylogeny and virulence gene profile.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, VMC2001, Cornell University, Ithaca, New York 14853, USA. kws5@cornell.edu
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Simpson
authors.forename: Belgin
authors.initials: B
authors.lastname: Dogan
authors.forename: Mark
authors.initials: M
authors.lastname: Rishniw
authors.forename: Richard E
authors.initials: RE
authors.lastname: Goldstein
authors.forename: Suzanne
authors.initials: S
authors.lastname: Klaessig
authors.forename: Patrick L
authors.initials: PL
authors.lastname: McDonough
authors.forename: Alex J
authors.initials: AJ
authors.lastname: German
authors.forename: Robin M
authors.initials: RM
authors.lastname: Yates
authors.forename: David G
authors.initials: DG
authors.lastname: Russell
authors.forename: Susan E
authors.initials: SE
authors.lastname: Johnson
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Berg
authors.forename: Josee
authors.initials: J
authors.lastname: Harel
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bruant
authors.forename: Sean P
authors.initials: SP
authors.lastname: McDonough
authors.forename: Ynte H
authors.initials: YH
authors.lastname: Schukken
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001706:Biopsy; D003092:Colitis / Q000382:microbiology / Q000662:veterinary*; D003106:Colon / Q000382:microbiology; D004283:Dog Diseases / Q000382:microbiology*; D004285:Dogs; D004847:Epithelial Cells / Q000382:microbiology; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity* / Q000502:physiology; D005260:Female; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008264:Macrophages / Q000382:microbiology; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014774:Virulence
chemical_list: D012336:RNA, Ribosomal, 16S