title: Colonic mucosa-associated diffusely adherent afaC+ Escherichia coli expressing lpfA and pks are increased in inflammatory bowel disease and colon cancer.
abstract: OBJECTIVE
  Colonic mucosa-associated Escherichia coli are increased in Crohn's disease (CD) and colorectal cancer (CRC). They variously haemagglutinate, invade epithelial cell lines, replicate within macrophages, translocate across M (microfold) cells and damage DNA. We investigated genes responsible for these effects and their co-association in colonic mucosal isolates.
  
  
  METHODS
  A fosmid library yielding 968 clones was prepared in E coli EPI300-T1 using DNA from a haemagglutinating CRC isolate, and resulting haemagglutinating clones were 454-pyrosequenced. PCR screening was performed on 281 colonic E coli isolates from inflammatory bowel disease (IBD) (35 patients), CRC (21) and controls (24; sporadic polyps or irritable bowel syndrome).
  
  
  RESULTS
  454-Pyrosequencing of fosmids from the haemagglutinating clones (n=8) identified the afimbrial adhesin afa-1 operon. Transfection of afa-1 into E coli K-12 predictably conferred diffuse adherence plus invasion of HEp-2 and I-407 epithelial cells, and upregulation of vascular endothelial growth factor. E coli expressing afaC were common in CRC (14/21, p=0.0009) and CD (9/14, p=0.005) but not ulcerative colitis (UC; 8/21) compared with controls (4/24). E coli expressing both afaC and lpfA (relevant to M-cell translocation) were common in CD (8/14, p=0.0019) and CRC (14/21, p=0.0001), but not UC (6/21) compared with controls (2/24). E coli expressing both afaC and pks (genotoxic) were common in CRC (11/21, p=0.0015) and UC (8/21, p=0.022), but not CD (4/14) compared with controls (2/24). All isolates expressed dsbA and htrA relevant to intra-macrophage replication, and 242/281 expressed fimH encoding type-1 fimbrial adhesin.
  
  
  CONCLUSIONS
  IBD and CRC commonly have colonic mucosal E coli that express genes that confer properties relevant to pathogenesis including M-cell translocation, angiogenesis and genotoxicity.
authors.affiliation: Department of Gastroenterology, Institute of Translational Medicine, , Liverpool, UK.
authors.forename: Maelle
authors.initials: M
authors.lastname: Prorok-Hamon
authors.forename: Melissa K
authors.initials: MK
authors.lastname: Friswell
authors.forename: Abdullah
authors.initials: A
authors.lastname: Alswied
authors.forename: Carol L
authors.initials: CL
authors.lastname: Roberts
authors.forename: Fei
authors.initials: F
authors.lastname: Song
authors.forename: Paul K
authors.initials: PK
authors.lastname: Flanagan
authors.forename: Paul
authors.initials: P
authors.lastname: Knight
authors.forename: Caroline
authors.initials: C
authors.lastname: Codling
authors.forename: Julian R
authors.initials: JR
authors.lastname: Marchesi
authors.forename: Craig
authors.initials: C
authors.lastname: Winstanley
authors.forename: Neil
authors.initials: N
authors.lastname: Hall
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Rhodes
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Campbell
mesh_terms: D018830:Adhesins, Escherichia coli / Q000378:metabolism; D001483:Base Sequence; D015415:Biomarkers / Q000378:metabolism; D018938:Caco-2 Cells; D016022:Case-Control Studies; D002460:Cell Line; D003106:Colon / Q000382:microbiology*; D003110:Colonic Neoplasms / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000472:pathogenicity; D029968:Escherichia coli Proteins / Q000378:metabolism*; D036781:Fimbriae Proteins / Q000378:metabolism*; D006388:Hemagglutinins / Q000378:metabolism; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000382:microbiology*; D007413:Intestinal Mucosa / Q000382:microbiology*; D008969:Molecular Sequence Data; D048630:Polyketide Synthases / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D018830:Adhesins, Escherichia coli; D015415:Biomarkers; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D006388:Hemagglutinins; C000588669:LpfA protein, E coli; D036781:Fimbriae Proteins; D048630:Polyketide Synthases
keywords: BACTERIAL ADHERENCE; BACTERIAL INTERACTIONS; BACTERIAL PATHOGENESIS; E. COLI; GUT INFLAMMATION