Inactivation of the haemophilus ducreyi luxS gene affects the virulence of this pathogen in human subjects

Maria Labandeira-Rey, Diane M. Janowicz, Robert J. Blick, Kate R. Fortney, Beth Zwickl, Barry P. Katz, Stanley M. Spinola, Eric J. Hansen

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12 Scopus citations

Abstract

Haemophilus ducreyi 35000HP contains a homologue of the luxS gene, which encodes an enzyme that synthesizes autoinducer 2 (AI-2) in other gram-negative bacteria. H. ducreyi 35000HP produced AI-2 that functioned in a Vibrio harveyi-based reporter system. A H. ducreyi luxS mutant was constructed by insertional inactivation of the luxS gene and lost the ability to produce AI-2. Provision of the H. ducreyi luxS gene in trans partially restored AI-2 production by the mutant. The luxS mutant was compared with its parent for virulence in the human challenge model of experimental chancroid. The pustule-formation rate in 5 volunteers was 93.3% (95% confidence interval, 81.7%-99.9%) at 15 parent sites and 60.0% (95% confidence interval, 48.3%-71.7%) at 15 mutant sites (1-tailed P<.001). Thus, the luxS mutant was partially attenuated for virulence. This is the first report of AI-2 production contributing to the pathogenesis of a genital ulcer disease.

Original languageEnglish (US)
Pages (from-to)409-416
Number of pages8
JournalJournal of Infectious Diseases
Volume200
Issue number3
DOIs
Publication statusPublished - Aug 1 2009

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ASJC Scopus subject areas

  • Infectious Diseases
  • Immunology and Allergy

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