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Updated: Aug 16, 2026

Synthesis and Assay of Vibrio Quorum Sensing Inhibitors
Published on: May 31, 2024
LuxS/autoinducer-2 quorum sensing molecule regulates transcriptional virulence gene expression in Clostridium
Alex Sek Yew Lee1, Keang Peng Song
1Microbial Pathogenesis Laboratory, Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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.
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