Gene regulated by luxS in Staphylococcus aureus (CBX75). unidentified

Autoinducer 2 (AI-2) is synthesized by LuxS enzyme and has been suggested as a universal language for interspecies communication shared by Gram-negative and Gram-positive bacteria. The signaling functions of LuxS/AI-2 in Staphylococcus aureus, a ubiquitous and opportunistic pathogen causing nosocomial infections worldwide, remain obscure. Here we show that LuxS regulates a number of genes according to the transcriptional profiling in S. aureus strain NCTC8325 and that inactivation of luxS gene resulted in decreased susceptibility to cell-wall-synthesis inhibitor antibiotics, enhanced biofilm formation, decreased autolysis and up-regulated vancomycin-resistance associated VraSR two-component regulatory system. These alterations were restored by either genetic complementation or addition of exogenous AI-2, suggesting that the LuxS/AI-2 system in S. aureus is associated with these physiological functions mainly by quorum sensing. Our findings add new understanding to AI-2 quorum sensing regulation in S. aureus and provide novel clues for antimicrobial chemotherapy of Staphylococal infection.