Table 1.

Some bacterial virulence determinants, which are regulated by AI-2/LuxS.

Organism	Signaling molecules	Receptors	Phenotype
E. coli	AI-2	LsrB, LsrR	Motility [33], biofilm formation [34]
S. typhimurium	AI-2	LsrB, LsrR	InvF [35]
S. aeurus	AI-2, AIP	AgrC, AgrA	Biofilm formation [36]
S. anginosus	AI-2	unknown	Susceptibility to antibiotics [37]
M. catarrhalis	AI-2	unknown	Biofilm formation and antibiotic resistance [38]
H. pylori	AI-2	TlpB	Motility [39]
V. cholerae	CAI-1, AI-2	CqsS, LuxP	Biofilm formation, virulence factor production and protease [19,40]
V. harveyi	HAI-1, CAI-1, AI-2	LuxN, CqsS, LuxP	Bioluminescence, biofilm formation, colony morphology, siderophore production, type III secretion and metalloprotease production [12,41,42]
V. fischeri	3-oxo-C6-HSL, C8-HSL, AI-2	AinR, LuxP, LuxR	Bioluminescence [43]
Y. pestis	3-oxo-C8-HSL, 3-oxo-C6-HSL, AI-2	LuxR homologue	Virulence factor expression [44]
A. actinomycetemcomitans	AI-2	RbsB, LsrB	Optimal growth under iron starvation and biofilm development [45]