Bacterial PolysaccharidesBacterial PolysaccharidesAnimal PathogensAnimal Pathogens••Salmonella Salmonella enteriditisenteriditis••E. coliE. coli••NeisseriaNeisseriameningitidismeningitidis••HaemophilusHaemophilusinfluenzaeinfluenzae••Proteus mirabilisProteus mirabilis••Proteus Proteus vulgarisvulgaris••MycobacteriaMycobacteria(many others)(many others)Soil BacteriaSoil Bacteria••RhizobiaceaeRhizobiaceae••Pseudomonas Pseudomonas solanacearumsolanacearum••ErwiniaErwiniaamylovoraamylovora(many others)(many others)PolysaccharidesPolysaccharides••ExtracellularExtracellularpolysaccharides (polysaccharides (EPSsEPSs))••Excreted Excreted heteropolysaccharidesheteropolysaccharides••Most often acidicMost often acidic••Frequently form solutions of high viscosityFrequently form solutions of high viscosity••GramGram--positive and Grampositive and Gram--negative productsnegative products••Capsular Polysaccharides (Capsular Polysaccharides (CPSsCPSs))••CellCell--associated associated heteropolysaccharidesheteropolysaccharides••Most often acidic, but some are neutralMost often acidic, but some are neutral••Solutions can be highly viscousSolutions can be highly viscous••GramGram--positive and Grampositive and Gram--negative productsnegative products••LipopolysaccharidesLipopolysaccharides((LPSsLPSs))••Component of the outer membraneComponent of the outer membrane••AmphiphilicAmphiphilic••GramGram--negative bacterial componentnegative bacterial component••TeichoicTeichoicacidacid••GramGram--PositivePositive••Mycobacterium cell wall componentsMycobacterium cell wall components••MycolylMycolylarabinogalactanarabinogalactan••LipooligosaccharidesLipooligosaccharides((LOSsLOSs))••GlycopeptidolipidsGlycopeptidolipids((GPLsGPLs))••PhenolicPhenolicglycolipidsglycolipids((PGLsPGLs))Polysaccharide FunctionsPolysaccharide Functions••Prevention of desiccationPrevention of desiccation••SurvivalSurvival••AdherenceAdherence••Colonization of oral surfacesColonization of oral surfaces••Colonization of cathetersColonization of catheters••BacteriaBacteria--plant interactionsplant interactions••Resistance to nonResistance to non--specific host immunityspecific host immunity••ComplementComplement--mediated mediated phagocytosisphagocytosis••ComplementComplement--mediated killingmediated killing••Resistance to specific host immunityResistance to specific host immunity••Poor antibody responsePoor antibody response••CellCell--cell recognition signalingcell recognition signaling••BacteriaBacteria--plant interactionsplant interactionsGramGram--Negative Bacterial Cell WallNegative Bacterial Cell WallCPSEPSLipopolysaccharidesLipopolysaccharides: Structure, Synthesis, : Structure, Synthesis, FunctionFunctionREAD: Raetz, and Whitfield. 2002. READ: Raetz, and Whitfield. 2002. LipopolysaccharideLipopolysaccharideEndotoxinsEndotoxins. Ann. Rev. . Ann. Rev. BiochemBiochem. 71:635. 71:635--700.700.Schematic Diagram of a Schematic Diagram of a LipopolysaccharideLipopolysaccharideLipid ACoreLipid ACoreO-ChainLipid ACoreO-ChainLPS IILPS ILPS III, IV, VExamples of Capsular Polysaccharides fromExamples of Capsular Polysaccharides fromEnteric BacteriaEnteric Bacteria44--ββ--DD--GlcAGlcA--1 41 4--αα--DD--GlcNAcGlcNAc--1 61 6--αα--DD--GlcNAcGlcNAc--11nnLL--SerineSerine--6 6 (amide)(amide)E. coliE. coliK40 CPSK40 CPS22--αα--DD--ManMan--1 31 3--ββ--DD--GalGal--11nnββ--DD--GlcAGlcA--1 31 3--αα--DD--GlcGlc--33E. coliE. coliK30 CPSK30 CPSGroup IGroup IGroup IIGroup II88--αα--Neu5AcNeu5Ac--2 92 9--αα--Neu5AcNeu5Ac--22nnE. coliE. coliK92 CPSK92 CPS33--ββ--DD--RibRib--1 71 7--ββ--KdoKdo--22nnE. coliE. coliK23 CPSK23 CPS(Whitfield and Valvano. 1993. Biosynthesis and expression(Whitfield and Valvano. 1993. Biosynthesis and expressionof cellof cell--surface polysaccharides in gramsurface polysaccharides in gram--negative bacteria. negative bacteria. Adv. Microbial. Adv. Microbial. PhysiolPhysiol..35:13535:135--246).246).E. coliE. coliCapsular PolysaccharideCapsular PolysaccharideE. coli K30 wtE. coli K30CPS minusE. coli K30CPS/LPS minusFrom"Current Topics in Microbiology and Immunology", 1990, Ed. by K. Jann and B. JannVirulence Functions of Virulence Functions of Bacterial Capsular and Bacterial Capsular and LipopolysaccharidesLipopolysaccharidesPseudomonas Pseudomonas aeroginosaaeroginosa((RocchettaRocchetta, Burrows, and Lam. 1999. Genetics of O, Burrows, and Lam. 1999. Genetics of O--antigen biosynthesis in antigen biosynthesis in PseudomonasPseudomonasaeruginosaaeruginosa. . MicrobiolMicrobiol. . andandMolecular Biol. RevMolecular Biol. Rev. 63:523. 63:523--553. READ pages 523553. READ pages 523--528)528)OOOHOHHHOOCHHHOHOHHOHHHHOHOHOOCOOHOHHHOOCHHHOHR2OOHHOHHHHOHHOOCR2OHNHAcHHOHHOOHCH3OHOHHCH3HOHNHAcHR2OOHHHHHOHOHOHR2OOHOHHHHOHOHCH3OHOHHHHHOOHCH3OOHOHHHHHOHOHR2R2AlginicAlginicAcidAcid--44--ββ--DD--ManAManA--11--44--αα--LL--GulAGulA--11--AA--Band LPS OBand LPS O--PolysaccharidePolysaccharide--33--αα--DD--RhaRha--11--22--αα--DD--RhaRha--11--33--αα--DD--RhaRha--11--O11 BO11 B--Band LPS OBand LPS O--PolysaccharidePolysaccharide--33--αα--LL--FucNAcFucNAc--11--33--ββ--DD--FucNAcFucNAc--11--22--ββ--DD--GlcGlc--11--Contributions ofContributions ofPseudomonasPseudomonasaeroginosaaeroginosaPolysaccharides to Polysaccharides to PathogenicityPathogenicityMutant strains which can not produce an LPS OMutant strains which can not produce an LPS O--chain polysaccharidechain polysaccharideare much less infective, and much more sensitive to serum killinare much less infective, and much more sensitive to serum killinggthan are wildthan are wild--type strains that have polysaccharide.type strains that have polysaccharide.OO--chain defective mutants are bound more efficiently by a receptorchain defective mutants are bound more efficiently by a receptoron theon thesurface of epithelial cells, presumably, resulting in greatersurface of epithelial cells, presumably, resulting in greateringestion and destruction of ingestion and destruction of P. P. aeroginosaaeroginosaby these cells.by these cells.BB--band polysaccharide is both immunogenic and able to confer serumband polysaccharide is both immunogenic and able to confer serumresistance, while Aresistance, while A--band polysaccharide is