Table 1

Quorum-sensing systems utilized by selected bacteria and associated phenotypes

OrganismSignalSynthase(s)Receptor(s)Selected phenotypesReference(s)
P. aeruginosaC4HSLRhlIRhlRExoenzymes, virulence, biofilm formation, motility, iron acquisition, pyocyanin6, 7
3OC12HSLLasILasR, QscR
HHQ, PQSPqsA to -D, PqsHPqsR
P. syringae3OC6HSLAhlIAhlREPS, plant colonization8
E. carotovora3OC6HSLCarICarR, ExpR, VirRCarbapenem, exoenzymes, virulence9
P. stewartii3OC6-HSLEsaIEsaRAdhesion, EPS, plant colonization8
B. glumaeC8HSLTofITofRMotility, toxoflavin, lipase, virulence10
A. tumefaciens3OC8HSLTraITraRTi plasmid conjugation, virulence8
C. violaceumC6HSLCviICviRExoenzymes, antibiotics, violacein11
S. liquefaciensC4HSLSwrISwrRSwarming motility, biofilm formation12
V. harveyi3OHC4HSLLuxMLuxNBioluminescence, siderophores, protease and EPS production, virulence13, 14
AI-2LuxSLuxP
CAI-1CqsACqsS
V. choleraeAI-2LuxSLuxPVirulence, biofilm formation, EPS13, 14
CAI-1CqsACqsS
V. fischeri3OC6HSLLuxILuxRBioluminescence, host colonization, motility13
C8HSLAinSAinR
AI-2LuxSLuxP
E. coli/S.Typhimurium3OC8HSLaNAdSdiAMotility, acid resistance15
AI-2LuxSLsrBlsr operon expression (AI-2 uptake)16
AI-3UnknownQseCVirulence, motility, biofilm formation17
S. aureusAIPagrDbAgrCVirulence, exotoxins, biofilm dispersal18
E. faecalisGBAPfsrDbFsrCGelatinase, protease19
cCF10ccfAbPrgXAdhesion, conjugation20
S. pneumoniaeCSPcomCbComDCompetence, virulence, autolysis21, 22, 23
B. thuringiensisPapRpapRbPlcRExoenzymes20
NprXnprRBb, cNprRToxins, sporulation, necrotrophism24, 25
X. campestrisDSFRpfB, RpfFRpfCVirulence, biofilm dispersal, EPS26
  • a SdiA can also bind C4HSL, C6HSL, 3OC6HSL, and 3OC12HSL but does so with less affinity than 3OC8HSL.

  • b The peptide signal is genetically encoded by the indicated gene.

  • c The gene encoding NprX-containing propeptide is also referred to in the literature as nprX.

  • d NA, not applicable.