Quorum sensing has an unexpected role in virulence in the model pathogen Citrobacter rodentium

Sarah J. Coulthrust, Simon Clare, Terry J. Evans, Ian J. Foulds, Kevin J. Roberts, Martin Welch, Gordon Dougan, George P.C. Salmond

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26 Citations (Scopus)


The bacterial mouse pathogen Citrobacter rodentium causes attaching and effacing (AE) lesions in the same manner as pathogenic Escherichia coli, and is an important model for this mode of pathogenesis. Quorum sensing (QS) involves chemical signalling by bacteria to regulate gene expression in response to cell density. E. coli has never been reported to have N-acylhomoserine lactone (AHL) QS, but it does utilize luxSdependent signalling. We found production of AHL QS signalling molecules by an AE pathogen, C. rodentium. AHL QS is directed by the croIR locus and a croI mutant is affected in its surface attachment, although not in Type III secretion. AHL QS has an important role in virulence in the mouse as, unexpectedly, the QS mutant is hypervirulent; by contrast, we detected no impact of luxS inactivation. Further study of QS in Citrobacter should provide new insights into AE pathogenesis. As the croIR locus might have been horizontally acquired, AHL QS might exist in some strains of pathogenic E. coli.

Original languageEnglish
Pages (from-to)698-703
Number of pages6
JournalEMBO Reports
Issue number7
Publication statusPublished - 1 Jul 2007
Externally publishedYes

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