Molecular characterization of a fimbrial adhesin, F1845, mediating diffuse adherence of diarrhea-associated Escherichia coli to HEp-2 cells

Abstract

A fimbrial adhesin, designated F1845, was found to be responsible for the diffuse HEp-2 cell adherence of a diarrheal Escherichia coli isolate. The genetic determinant of F1845 was cloned, and the order of the genes necessary for production of F1845 was determined by maxicell analysis. Five polypeptides with apparent sizes of 10, 95, 27, 15.5, and 14.3 kilodaltons (kDa) were found to be encoded in that order by the F1845 determinant. The nucleotide sequence of the 14.3-kDa subunit gene was determined and found to share extensive homology in its signal sequence with the gene encoding the structural subunit of the AFA-1 hemagglutinin of a uropathogenic E. coli strain (A. Labigne-Roussel, M.A. Schmidt, W. Walz, and S. Falkow, J. Bacteriol. 162:1285-1292, 1985) but not in the region encoding the mature protein. Southern blot hybridizations indicated that the F1845 determinants are of chromosomal origin. Hybridization studies using a probe from the region encoding the 95-kDa polypeptide indicated that related sequences may be plasmid associated in some strains and chromosomal in others. Additional hybridization studies of E. coli isolates possessing sequence homology to the F1845 determinant suggest that the sequences in the 5' region of the F1845 structural subunit gene are more highly conserved than sequences in the 3' region.

Mecanismos de virulencia de Escherichia coli enteropatógena

“…F1845 es una adhesina fimbrial que pertenece a la cepa C1845 de tipo silvestre que tiene como receptor hDAF. Al originarse esta unión, ocurre un alargamiento de las microvellosidades 127 . La otra adhesina es AIDA-I, que pertenece a la familia de autotransportadores de membrana externa de 100 kDa y se ha encontrado en la cepa 0:126H:2 128 .…”

Purification and characterization of thin, aggregative fimbriae from Salmonella enteritidis

“…Biochemical data for approximately 50 fimbrial types were analyzed, and none of these fimbriae had the same combination of biochemical characteristics as the thin, aggregative fimbriae of S. enteritidis 27655-3b. Relatively few fimbriae have a similar low percentage of hydrophobic residues (Table 2) (2,8,14,31,59), and only Haemophilus influenzae fimbriae (22), type 3 fimbriae of S. enteritidis 1380-36/71, and coiled fimbriae of E. coli IH11033 share the characteristic of a relatively high percentage of potentially acidic residues (Table 2). Moreover, a FASTA computer search of N-terminal sequence data contained in SWISS-PROT and GENPEPT or our own fimbria resembled those of other fimbriae in that it was composed mainly of polar uncharged or hydrophobic residues.…”

“…In addition, some E. coli produce thin (2-nm), coiled fibrils named curli, which are noted for their ability to mediate bacterial adherence to fibronectin (42). Numerous other fimbriae in various E. coli strains have been described but have yet to be biochemically characterized in detail (8,10,14,24,55,58).…”

High Resolution Studies of the Afa/Dr Adhesin DraE and Its Interaction with Chloramphenicol

“…Although originally thought to be afimbrial, the Afa/Dr adhesins have been shown to form extended fimbrial structures on the surface of bacteria (5)(6)(7)(8)(9). These structures are made up of the E protein, which acts as both the adhesin and the major structural subunit (10,11), and the D protein, which caps the structure and acts as the invasin (12).…”