Small Talk

Cell-to-Cell Communicationin Bacteria

Prokaryotic (Bacterial) Cells

V. fischeri Quorum Sensing

LuxI

Luciferase Genes

LuxR

LuxR

Quorum Sensing In Bacteria

LuxI

Target genes

LuxR

LuxR

Acyl-Homoserine Lactone Autoinducers

LuxI-LuxR Quorum Sensing Systems

V. fischeri

P. aeruginosa

A. tumefaciens

E. carotovora

Bioluminescence

Virulence Factors, Biofilms

Mating, Transfer of Mobile DNA

Virulence Factors, Antibiotic Synthesis

LuxN

LuxQ

AI-1

AI-2

Luciferase Genes

Light

Quorum Sensing in V. harveyi

LuxNAI-1

AI-2

V. harveyi Reporter Strain AI-1

Luciferase Genes

Light

LuxQ

AI-1

AI-2

Luciferase Genes

Light

V. harveyi Reporter Strain AI-2

Quorum Sensing in E. coli and Salmonella

Actinobacillus actinomycetemcomitansActinobacillus pleuropneumoniaeActinobacillus suisBacillus anthracisBacillus haloduransBacillus subtilisBorrelia burgdorferiCampylobacter jejuniClostridium acetobutylicumClostridium difficileClostridium perfringensDeinococcus radioduransEscherichia coli MG1655Escherichia coli O157:H7Enterococcus faecalisHaemophilus influenzaeHelicobacter pyloriKlebsiella pneumoniaeLactococcus lactisLeuconostoc oenosListeria monocytogenesMannheimia haemolytica

Neisseria gonorrhoeae Neisseria meningitidisPasteurella multocidaPasteurella trehalosiPorphyromonas gingivalisProteus mirabilisSalmonella paratyphiSalmonella typhiSalmonella typhimuriumShewanella putrefaciensShigella flexneriStaphylococcus aureusStaphylococcus epidermidisStreptococcus gordoniiStreptococcus mutansStreptococcus pneumoniaeStreptococcus pyogenesVibrio choleraeVibrio harveyi Vibrio parahaemolyticusVibrio anguillarumVibrio vulnificusYersinia pestis

Bacteria That Contain luxS(A sample of 534 genomes sequenced)

Targets of AI-2Actinobacillus actinomycetemcomitans Periodontal virulence, Mixed-species biofilmsBacillus anthracis GrowthBacillus cereus BiofilmsBacillus subtilis DevelopmentBorrelia burgdorferi VirulenceCampylobacter jejuni Motility, ToxinsClostridium difficile Virulence, ToxinsClostridium perfringens Virulence, ToxinsEscherichia coli K12 AI-2 transport, Biofilms, Cell division, DNA processing, Iron uptakeEscherichia coli EHEC O157:H7 Virulence, Type III Secretion , MotilityEscherichia coli EPEC Motility, Type III SecretionHaemophilus influenzae Virulence, Cell invasionHelicobacter pylori Motility, BiofilmsKlebsiella pneumoniae BiofilmsLactobacillus reuteri Biofilms in miceListeria monocytogenes BiofilmsMannheimia haemolytica Virulence, Encapsulation, AdhesionNeisseria meningitidis Virulence, BacteremiaPhotorhabdus luminescens Antibiotic productionPorphyromonas gingivalis Virulence, Proteases Hemin acquisition, Stress responseSalmonella typhi BiofilmsSalmonella typhimurium AI-2 transport, BiofilmsSerratia marcescens Virulence in C. elegans, Hemolysin, Antibiotic productionShigella flexneri VirB (virulence factor)Staphylococcus epidermis Virulence, BiofilmsStreptococcus gordonii Mixed-species biofilmsStreptococcus mutans Virulence, Biofilms, Competence, Stress responseStreptococcus pneumoniae Virulence, Persistence, CompetenceStreptococcus pyogenes Virulence factors, Protease, HemolysinVibrio anguillarum ProteaseVibrio cholerae Virulence, Toxins, BiofilmsVibrio fischeri Bioluminescence, ColonizationVibrio harveyi Bioluminescence, Biofilms, Siderophore, Virulence, Type III Secretion, Protease

LuxN

LuxQ

AI-1

AI-2

Quorum Sensing in V. harveyi

Luciferase Genes

Light

4,5-Dihydroxy-2,3-Pentanedione

Inter-Species CommunicationThe Structure of AI-2

LuxN

LuxQ

AI-1

AI-2

Luciferase Genes

Light

LuxS

Making Antibiotics Based on AI-2

AI-2 AI-2Analog

CHEMISTRY

Making Antibiotics Based on AI-2

LuxQAI-2

Luciferase Genes

No Light

AI-2 Quorum Sensing in V. harveyi

LuxNAI-1

Luciferase Genes

Light

AI-1 Quorum Sensing in V. harveyi

Virulent Bacteria

Test Substance

Inject

Making Antibiotics Based on AI-2

Deador

Alive

Quorum Sensing In Bacteria

Bacteria Talk to Each Other

Bacteria Distinguish Self from Other

Opportunities for Novel Biotechnological Applications ToImpede/Enhance Quorum Sensing Controlled Functions

Quorum Sensing Allows Bacteria To Be Multi-CellularSimilar to Higher Organisms

Many More Molecules Remain To Be Discoveredi.e., molecules that tell “who” the other is

Natural Anti-Quorum Sensing Strategies Already Exist

Multiple Languagesi.e., intra- and inter-species communication