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.

Asad and Opal Critical Care 2008 12:236   doi:10.1186/cc7101