title: Long polar fimbriae and tissue tropism in Escherichia coli O157:H7.
abstract: In vitro organ culture has demonstrated the human intestinal tropism of enterohaemorrhagic Escherichia coli O157:H7 for follicle associated epithelium overlying Peyer's patches of the terminal ileum. Long polar (LP) fimbriae are considered to mediate the attachment of Salmonella enterica serovar Typhimurium to Peyer's patch epithelium and, as homologous genes have been identified in O157:H7, we hypothesised that LP fimbriae in O157:H7 may perform the same function. However, mutation of LP fimbriae in O157:H7 strain 85/170 resulted in the novel phenotype of proximal and distal small intestinal colonisation with attaching/effacing lesion formation, while retaining adhesion to follicle associated epithelium. Application of whole genome DNA array technology did not identify changes in known fimbrial genes that could explain the change in tropism, but highlighted several genes that require further investigation. LP fimbrial genes are the first genes to be identified outside the locus of enterocyte effacement pathogenicity island that influence O157:H7 human intestinal tissue tropism.
authors.affiliation: Centre for Paediatric Gastroenterology, Royal Free Hospital, London, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Fitzhenry
authors.forename: Sivan
authors.initials: S
authors.lastname: Dahan
authors.forename: Alfredo G
authors.initials: AG
authors.lastname: Torres
authors.forename: Yuwen
authors.initials: Y
authors.lastname: Chong
authors.forename: Robert
authors.initials: R
authors.lastname: Heuschkel
authors.forename: Simon H
authors.initials: SH
authors.lastname: Murch
authors.forename: Mike
authors.initials: M
authors.lastname: Thomson
authors.forename: James B
authors.initials: JB
authors.lastname: Kaper
authors.forename: Gad
authors.initials: G
authors.lastname: Frankel
authors.forename: Alan D
authors.initials: AD
authors.lastname: Phillips
mesh_terms: D018830:Adhesins, Escherichia coli / Q000235:genetics / Q000502:physiology; D000293:Adolescent; D001422:Bacterial Adhesion / Q000502:physiology*; D001706:Biopsy; D002460:Cell Line; D002675:Child, Preschool; D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000235:genetics / Q000472:pathogenicity* / Q000648:ultrastructure; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D020869:Gene Expression Profiling; D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology*; D008854:Microscopy, Electron; D016254:Mutagenesis, Insertional; D009154:Mutation; D009924:Organ Culture Techniques; D012486:Salmonella typhimurium / Q000235:genetics
chemical_list: D018830:Adhesins, Escherichia coli