Bench-to-bedside review: Quorum sensing and the role of cell-to-cell communication during invasive bacterial infection

Table 2 Selected quorum sensing inhibitors as potential therapeutic agents

Agent	References	Target	Proposed mechanism of action	Current status
Macrolide and aminoglycoside antibiotics	[24, 66, 71]	AHL signal generation	Inhibit C₁₂-homoserine lactone by Pseudomonas aeruginosa quorum sensing system	Experimental use of existing antibiotics
S-adenosyl-homosysteine	[70]	AHL signal generation	Inhibits generation of AHL by RhlI synthesis	In vitro testing
Antibody to AHL	[80]	C₁₂-homoserine lactone of P. aeruginosa	Antibodies to AHL block cell to cell Signaling	In vitro and animal models
AiiA degrading enzymes	[70]	AHL lactone ring	Lactonolysis of AHL disrupts signaling potential	In vitro testing; might be useful as topical agent
PvdQ-type degrading enzymes	[70]	Fatty acid side chain of AHL	Aminoacylase releases fatty acid and destabilizes lactone ring	In vitro studies
Halogenated furanones, other natural or synthetic AHL analogues	[70, 72, 73, 75]	AHL receptors and LuxR homologues	Competitive inhibitors for AHL receptor binding	In vitro and animal studies
RIP and similar RNAIII-inhibiting peptides	[47, 76, 78, 79]	TRAP in agr peptide system	Inhibits phosphorylation of TRAP blocking RNAIII signaling	In vitro and animal studies
RAP inhibitors	[77]	RNAIII-activating protein of staphylococci	Bind RAP and block agr activation	In vitro and animal studies

agr, accessory gene regulator; AHL, N-acyl homoserine lactone; RAP, RNAIII-activating protein; RIP, RNAIII-inhibiting peptide; TRAP, target of RNAIII-activating protein.

ISSN: 1364-8535