Quorum sensing in Campylobacter jejuni: detection of a luxS encoded signalling molecule.
The expression of a wide variety of physiological functions in many bacterial species is modulated by quorum sensing, a population-dependent signalling mechanism that involves the production and detection of extracellular signalling molecules. The genome sequence of Campylobacter jejuni NCTC 11168 contains a gene encoding an orthologue of LuxS, which is required for autoinducer-2 (AI-2) production in other bacterial species, but does not contain genes predicted to encode any known acyl-homoserine lactone synthetase. This study demonstrates that C. jejuni produces functional AI-2 activity through the ability of cell-free extracts to specifically induce bioluminescence in Vibrio harveyi BB170, a reporter strain for quorum-sensing system 2. Production of this signalling compound was shown to be dependent upon the product of the C. jejuni luxS gene (Cj1198). While the luxS mutant showed comparable growth rate, resistance to oxidative stress and ability to invade Caco-2 cell monolayers to the parental strain, it exhibited decreased motility haloes in semisolid media, suggesting a role for quorum sensing in the regulation of motility.
Elvers
Karen T
KT
School of Biomedical and Life Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK1.
Park
Simon F
SF
School of Biomedical and Life Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK1.
D000595:Amino Acid Sequence; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018938:Caco-2 Cells; D016123:Campylobacter jejuni / Q000166:cytology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D013437:Carbon-Sulfur Lyases; D015169:Colony Count, Microbial; D006801:Humans; D008163:Luminescent Measurements; D008969:Molecular Sequence Data; D009154:Mutation; D018384:Oxidative Stress; D010641:Phenotype; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D001426:Bacterial Proteins; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria