FimH-mediated autoaggregation of Escherichia coli

Citation
Ma. Schembri et al., FimH-mediated autoaggregation of Escherichia coli, MOL MICROB, 41(6), 2001, pp. 1419-1430
Citations number
58
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
MOLECULAR MICROBIOLOGY
ISSN journal
0950-382X → ACNP
Volume
41
Issue
6
Year of publication
2001
Pages
1419 - 1430
Database
ISI
SICI code
0950-382X(200109)41:6<1419:FAOEC>2.0.ZU;2-2
Abstract
Autoaggregation is a phenomenon thought to contribute to colonization of ma mmalian hosts by pathogenic bacteria. Type 1 fimbriae are surface organelle s of Escherichia coli that mediate D-mannose-sensitive binding to various h ost surfaces. This binding is conferred by the minor fimbrial component Fim H. In this study, we have used random mutagenesis to identify variants of t he FimH adhesin that confer the ability of E. coli to autoaggregate and set tle from liquid cultures. Three separate autoaggregating clones were identi fied, all of which contained multiple amino acid changes located within the N-terminal receptor-binding domain of FimH. Autoaggregation could not be i nhibited by mannose, but was inhibited by growth at temperatures at or belo w 30 degreesC. Using green fluorescent protein (GFP) as a reporter, we show that the autoaggregating clones do not mix with wild-type fimbriated cells . Electron microscopy shows that autoaggregating cells produce fimbriae wit h a twisted and entangled appearance. We present evidence that autoaggregat ing versions of FimH also occur in nature. Our results stress the highly ad aptive nature of the ubiquitous FimH adhesin.