Fig. 2.

Mechanism of QS system for S. aureus biofilm regulation. In the Agr system, RNAII consists of agrB/D/C/A genes, encoding the AgrB/D/C/A proteins required for the biosynthesis, transport, and target gene regulation of AIP. RNAIII, as an essential effector, upregulate genes encoding exoproteins and downregulate genes encoding surface adhesins. In the LuxS/AI-2 system, LuxS catalyzes the synthesis of AI-2, inhibits Rbf and promotes icaR expression to repress IcaA/D/B/C, ultimately reducing the formation of PIA-dependent biofilms. QS, Quorum sensing; Agr, accessory gene regulator protein locus; AIP, auto-inducing peptide; PSM, phenol-soluble modulin; LuxS, S-ribosylhomocysteine lyase; AI-2, interspecies autoinducer. Key molecules of potential antibiofilm targets are underlined.