Open AccessIha: a Novel Escherichia coli O157:H7 Adherence-Conferring Molecule Encoded on a Recently Acquired Chromosomal Island of Conserved Structure
Author(s) -
Phillip I. Tarr,
Sima S. Bilge,
James C. Vary,
Srdjan Jelačić,
Rebecca L. Habeeb,
Teresa R. Ward,
Michael Baylor,
Thomas E. Besser
Publication year - 2000
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.68.3.1400-1407.2000
Subject(s) - biology , escherichia coli , bacterial adhesin , gene , microbiology and biotechnology , genetics , cosmid
The mechanisms used by Shiga toxin (Stx)-producingEscherichia coli to adhere to epithelial cells are incompletely understood. Two cosmids from anE. coli O157:H7 DNA library contain an adherence-conferring chromosomal gene encoding a protein similar to iron-regulated gene A (IrgA) ofVibrio cholerae (M. B. Goldberg, S. A. Boyko, J. R. Butterton, J. A. Stoebner, S. M. Payne, and S. B. Calderwood, Mol. Microbiol. 6:2407–2418, 1992). We have termed the product of this gene the IrgA homologue adhesin (Iha), which is encoded byiha . Iha is 67 kDa inE. coli O157:H7 and 78 kDa in laboratoryE. coli and is structurally unlike other known adhesins. DNA adjacent toiha contains tellurite resistance loci and is conserved in structure in distantly related pathogenicE. coli , but it is absent from nontoxigenicE. coli O55:H7, sorbitol-fermenting Stx-producingE. coli O157:H−, and laboratoryE. coli . We have termed this region the tellurite resistance- and adherence-conferring island. We conclude that Iha is a novel bacterial adherence-conferring protein and is contained within anE. coli chromosomal island of conserved structure. PathogenicE. coli O157:H7 has only recently acquired this island.