Table 1.

Elucidated mechanisms and targets of QSI in AHL-mediated QS systems.

QS inhibitor	Mode of action	Inhibition target: protein, AHL or bacteria	Reference
Sinefungin, butyryl-SAM and MTA	AHL synthesis inhibition	RhlI protein of P. aeruginosa.	[75]
Compound J8-C8	AHL synthesis inhibition	TofI protein of B. glumae.	[76]
Tannic acid; trans-cinnamaldehyde	AHL synthesis inhibition	RhlI protein of P. aeruginosa.	[77]
Triclosan	AHL synthesis inhibition	Enoyl-ACP reductase (FabI) of P. aeruginosa.	[74]
Antibiotic amikacin	AHL synthesis inhibition	CviI of C. violaceum.	[78]
Thioether compound JKR-1	AHL synthesis inhibition	CepI of B. cenocepecia.	[73]
Lactonase AiiA from Bacillus sp. Strain 240B1	QQ enzyme/AHL inactivation	AHLs from Erwinia carotovora.	[84]
Lactonase AhlS from Solibacillus silvestris	QQ enzyme/AHL inactivation	C10-HSL.	[97]
Lactonase PPH from Mycobacterium tuberculosis	QQ enzyme/AHL inactivation	AHLs secreted by E. amylovora (C6-oxo-HSL).	[85]
Enzyme moLRP (marine-originated lactonase-related protein)	QQ enzyme/AHL inactivation	Low- to medium-chain AHLs, like C4-HSL and C6-oxo-HSL.	[82]
Penicillin acylase from Streptomyces lavendulae	QQ enzyme/AHL degradation	Long-chain AHLs, mainly C10-HSL, C12-HSL and C14-HSL.	[98]
Acylase from Actinoplanes utahensis	QQ enzyme/AHL degradation	Long-chain AHLs, mainly C8-HSL, C10-HSL, and C12-HSL.	[98]
Acylase APTM01 from Pseudoalteromonas tetraodonis	QQ enzyme/AHL degradation	Long-chain AHLs, mainly C10-HSL, C12-HSL and 3-oxo-C12-HSL.	[86]
Antibodies RS2-1G9	AHL sequestration	Inhibition of 3-oxo-C12-HSL of P. aeruginosa.	[87]
Analogs of 3-oxo-C12-HSL	Inhibition of response regulator	TraR protein of Agrobacterium tumefaciens.	[88]
Halogenated furanones	Inhibition of response regulator	Destabilization of LuxR.	[91,99]
Furanones	Inhibition of response regulator	Destabilizing LasR of P. aeruginosa, promoting its degradation.	[95]
Chlorolactone compound	Inhibition of response regulator	Competition with C6-HSL for binding site of CviR from C. violaceum.	[96]