title: PapG-dependent adherence breaks mucosal inertia and triggers the innate host response.
abstract: Mucosal pathogens differ from normal flora constituents in that they provoke a host response that upsets mucosal integrity. We investigated whether the elaboration of discrete adherence factors is sufficient to break the inertia of the mucosal barrier. PapG-mediated adherence was selected as an example, because P fimbrial expression characterizes uropathogenic Escherichia coli and because adherence starts the attack on the mucosal barrier. Patients were inoculated intravesically with transformed nonvirulent E. coli strains expressing functional P fimbriae (E. coli pap(+)) or mutant fimbriae lacking the adhesin (E. coli Delta papG). E. coli pap(+) was shown to activate the innate host response, and adherent gfp(+) bacteria were observed on excreted uroepithelial cells. E. coli Delta papG failed to trigger a response and was nonadhesive. We conclude that PapG-mediated adherence breaks mucosal inertia in the human urinary tract by triggering innate immunity and propose that this activation step differentiates asymptomatic carriage from infection.
authors.affiliation: Department of Microbiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: Goran
authors.initials: G
authors.lastname: Bergsten
authors.forename: Martin
authors.initials: M
authors.lastname: Samuelsson
authors.forename: Bjorn
authors.initials: B
authors.lastname: Wullt
authors.forename: Irene
authors.initials: I
authors.lastname: Leijonhufvud
authors.forename: Hans
authors.initials: H
authors.lastname: Fischer
authors.forename: Catharina
authors.initials: C
authors.lastname: Svanborg
mesh_terms: D018830:Adhesins, Escherichia coli / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D000328:Adult; D000368:Aged; D001422:Bacterial Adhesion; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D004927:Escherichia coli Infections / Q000276:immunology / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000378:metabolism; D005260:Female; D036781:Fimbriae Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000378:metabolism; D006801:Humans; D007113:Immunity, Innate; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000276:immunology*; D014551:Urinary Tract / Q000382:microbiology; D014552:Urinary Tract Infections / Q000276:immunology / Q000382:microbiology
chemical_list: D018830:Adhesins, Escherichia coli; D029968:Escherichia coli Proteins; C092426:PapG protein, E coli; D036781:Fimbriae Proteins