title: LuxS/autoinducer-2 quorum sensing molecule regulates transcriptional virulence gene expression in Clostridium difficile.
abstract: Toxigenic Clostridium difficile CCUG19126 produces the autoinducer-2 (AI-2) quorum sensing molecule that induces bioluminescence in Vibrio harveyi BB170 reporter strain. AI-2-containing cell-free supernatants from mid-log phase C. difficile and Escherichia coli DH5alpha expressing recombinant luxS(cd) upregulated the transcript levels of tcdA (7-10-fold), tcdB (4-6-fold), and tcdE (2-3-fold) in early-log C. difficile. In contrast, no induction occurred when cells were exposed to sterile medium or to cell-free supernatant from E. coli DH5alpha. AI-2 did not significantly increase the level of toxin A in early-log C. difficile. These results suggest that LuxS(cd)-dependent signaling regulates virulence gene expression at the transcriptional level in C. difficile.
authors.affiliation: Microbial Pathogenesis Laboratory, Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Alex Sek Yew
authors.initials: AS
authors.lastname: Lee
authors.forename: Keang Peng
authors.initials: KP
authors.lastname: Song
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology*; D001483:Base Sequence; D013437:Carbon-Sulfur Lyases; D003001:Cloning, Molecular; D016360:Clostridioides difficile / Q000235:genetics / Q000472:pathogenicity*; D017931:DNA Primers; D004269:DNA, Bacterial; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D014158:Transcription, Genetic / Q000502:physiology*; D014774:Virulence / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria