title: F17-like fimbriae from an invasive Escherichia coli strain producing cytotoxic necrotizing factor type 2 toxin.
abstract: The F17b fimbriae encoded by the transmissible virulence plasmid Vir, also coding for cytotoxic necrotizing factor type 2, were characterized. A 5.7-kb region of Vir mediates in vitro N-acetylglucosamine-sensitive adhesion to calf intestinal villi. Sequence analysis revealed that this region codes for a structural subunit and an adhesin closely related to the F17-A and F17-G proteins encoded by the F17 fimbrial gene cluster. The F17b-A gene presents an open reading frame of 540 bp encoding a polypeptide of 180 amino acids with a putative signal peptide of 21 residues. The mature protein shows an identity of 74% with the F17-A structural subunit. This 20-kDa protein is recognized by antiserum directed against F17 fimbriae. The F17b-G gene shows an open reading frame of 1,029 bp encoding a polypeptide of 343 amino acids with a putative signal peptide of 22 residues. The F17b-G polypeptide exhibits 95% identity with the F17-G adhesin. The functional homology of the gene products was further confirmed by demonstrating that mutants in the F17-A gene can be complemented by the F17b-A gene and vice versa. These results prove that fimbriae belonging to the F17 family are also found on pathogenic Escherichia coli strains other than enterotoxigenic isolates producing heat-labile or heat-stable enterotoxin.
authors.affiliation: Laboratorium Genetische Virologie, Vrije Universiteit Brussel, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: el Mazouari
authors.forename: E
authors.initials: E
authors.lastname: Oswald
authors.forename: J P
authors.initials: JP
authors.lastname: Hernalsteens
authors.forename: P
authors.initials: P
authors.lastname: Lintermans
authors.forename: H
authors.initials: H
authors.lastname: De Greve
mesh_terms: D018830:Adhesins, Escherichia coli; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000096:biosynthesis*; D001483:Base Sequence; D003603:Cytotoxins / Q000096:biosynthesis*; D004926:Escherichia coli / Q000472:pathogenicity*; D029968:Escherichia coli Proteins; D010861:Fimbriae, Bacterial; D008969:Molecular Sequence Data; D010957:Plasmids; D037521:Virulence Factors
chemical_list: D018830:Adhesins, Escherichia coli; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003603:Cytotoxins; D029968:Escherichia coli Proteins; D037521:Virulence Factors; C060296:cytotoxic necrotizing factor type 1