-Hemolytic Streptococci-Hemolytic Streptococci

Ali Somily Ali Somily MD,FRCPC,D(ABMM)MD,FRCPC,D(ABMM)

IntroductionIntroduction

Grouped either by :Grouped either by :• A.phenotypicA.phenotypic

1.1. Hemolysis(Hemolysis(,ß or ,ß or ))

2.2. Lancefield antigenLancefield antigen– Cell wall CHOCell wall CHO

– A,B,C,D,Fand G ectA,B,C,D,Fand G ect

Or B.GenotypicOr B.Genotypic

&ß Hemolysis&ß Hemolysis

Lancefield AgglutinationLancefield Agglutination

-Hemolytic Streptococci-Hemolytic Streptococci

Partial hemolysis of bloodPartial hemolysis of blood Green zoon around the colonyGreen zoon around the colony Examples:Examples:

• S.PneumoniaeS.Pneumoniae• S.ViridansS.Viridans• EnterococcusEnterococcus• S.BovisS.Bovis

STREPTOCOCCUS PNEUMONIAESTREPTOCOCCUS PNEUMONIAE

Aerobic extracellular Aerobic extracellular Feature :Feature :

• Gram Positive cocci in pairs or short chains(Lancet Gram Positive cocci in pairs or short chains(Lancet shape)shape)

• Colony :Gray –white variable on BAPColony :Gray –white variable on BAP Non motile Non motile Capsule : Polysaccharidemore than 80 types Capsule : Polysaccharidemore than 80 types Note : No Glycocalyx , No ExotoxinNote : No Glycocalyx , No Exotoxin

Virulence FactorsVirulence Factors

Capsule: Polysaccharide (resist phagocytosisCapsule: Polysaccharide (resist phagocytosis IgA Protease:Prevent Opsonization by IgA at IgA Protease:Prevent Opsonization by IgA at

Mucous MembraneMucous Membrane Adhesion: Mediates attachement of Adhesion: Mediates attachement of

S.pneumoniae to Epithelial CellS.pneumoniae to Epithelial Cell Autolysin/PneumolysinAutolysin/Pneumolysin

Quellung TestQuellung Test

(AB’s(AB’s swelling of capsule swelling of capsule

CULTURECULTURE

BAP; 5-10%CO2BAP; 5-10%CO2 -hemolytic Mucoid -hemolytic Mucoid

(capsule) S(capsule) SRR Concave (punched Concave (punched

out/collapse)out/collapse)

Laboratory TestsLaboratory Tests

Catalase : -veCatalase : -ve Hemolysis : AlphaHemolysis : Alpha 6.5% Nacl : No growth6.5% Nacl : No growth CAMP Test : -veCAMP Test : -ve Bile Esculin: -veBile Esculin: -ve Bile Solubility : +veBile Solubility : +ve Optochin :SensitiveOptochin :Sensitive Lancefiield : None (CHO C)Lancefiield : None (CHO C)

IDENTIFICATIONIDENTIFICATION

Bile solubility (NaDC)Bile solubility (NaDC)

Optochin S (disk Optochin S (disk 55g&6mmg&6mmzoon>=14 zoon>=14 mm)mm)

Source and TransmissionSource and Transmission

Normal Flora of Upper Respiratory Tract in Normal Flora of Upper Respiratory Tract in 20-40% of people 20-40% of people

Horizontal Transmission via Droplet and Horizontal Transmission via Droplet and InhalationInhalation

Pulmonary infection due failure of Pulmonary infection due failure of Muccocilliary action Muccocilliary action AlveoliAlveoliLobeLobe

Meningitis after Sinusitis , Otitis Media or Meningitis after Sinusitis , Otitis Media or Bacteremia through Choroid PlexusBacteremia through Choroid Plexus

ClinicalClinical

Primary infectionPrimary infection• Community Acquired Community Acquired

PneumoniaPneumonia

• BacteremiaBacteremia

• EndocarditisEndocarditis

• MeningitisMeningitis

• LocalizedLocalized SinusitisSinusitis O.MO.M

Secondary InfectionSecondary Infection• Non-capsulatedNon-capsulated

• Opportunistic infectionOpportunistic infection

• Lungs onlyLungs only

• Impair or poor ciliary Impair or poor ciliary activityactivity

Viral, Smoking, dustViral, Smoking, dust

Lober PneumoniaLober Pneumonia

Adult and Sickle Cell Adult and Sickle Cell DiseaseDisease

Fever , cough(sputum), Fever , cough(sputum), Dull on PercussionDull on Percussion

Can be fatal, Abscesses Can be fatal, Abscesses Diagnosis: Sputum GS Diagnosis: Sputum GS

and Cultureand Culture

Risk factorRisk factor• HyposplenismHyposplenism

SplenectomySplenectomy AspleniaAsplenia Sickle Cell DiseasesSickle Cell Diseases

• Liver diseaseLiver disease• HypogammaglobinaemiaHypogammaglobinaemia• AlcoholismAlcoholism• Cigarette smokingCigarette smoking• Viral InfectionViral Infection• MalnutritionMalnutrition

MeningitisMeningitis

Adult and ElderlyAdult and Elderly Symptoms: fever, neck Symptoms: fever, neck

Pain,Neck rigidity Pain,Neck rigidity Medical EmergencyMedical Emergency Lumbar Puncture Lumbar Puncture PMNs , Protein,PMNs , Protein, Glucose and Cloudy Glucose and Cloudy Direct Extension : Direct Extension :

Sinises,OM or Through Sinises,OM or Through BloodBlood

Sinusitis and O.MSinusitis and O.M

Sinusitis : S.pneumoniae most common cause, Sinusitis : S.pneumoniae most common cause, follow allergy or viral infectionfollow allergy or viral infection

O.M : S.pneumoniae most common cause, O.M : S.pneumoniae most common cause, follow allergy or viral infection which prevent follow allergy or viral infection which prevent eustachian tube drainage. eustachian tube drainage.

Host Defense and ImmunityHost Defense and Immunity

IgG AntibodiesIgG Antibodies : : Type specific immunityType specific immunity

Classical Pathway ImmunityClassical Pathway Immunity: : C1 activated by capsule: Antibody -dependent C1 activated by capsule: Antibody -dependent OpsonizationOpsonization

Alternative Pathway ComplementAlternative Pathway Complement Antibody Antibody -independent Opsonization-independent Opsonization

C5a complementC5a complement : chemotaxis attract PMNs : chemotaxis attract PMNs VaccineVaccine :Immunity for few years :Immunity for few years

Treatment and PreventionTreatment and Prevention TreatmentTreatment

• PenicillinG PenicillinG ↑ resistant↑ resistant recently due to PBP alternation recently due to PBP alternation• Ceftriaxone for meningitisCeftriaxone for meningitis• Ceftriaxone +/-Vancomycin and or Rifampicin Ceftriaxone +/-Vancomycin and or Rifampicin

VaccinationVaccination• Polsaccharide capsulePolsaccharide capsule• Conjugate vaccineConjugate vaccine• IndicationIndication

ChildrenChildren SCDSCD Splenectomised patientSplenectomised patient HIVHIV ElderlyElderly Cardiopulmonary and renal diseasesCardiopulmonary and renal diseases

VIRIDANS STREPTOCOCCIVIRIDANS STREPTOCOCCI

Streptococcus Viridans GroupStreptococcus Viridans Group1.1. MitisMitis2.2. MutansMutans3.3. SalvariusSalvarius4.4. AngionosisAngionosis

Extracellular aerobic Gram positive cocci in Extracellular aerobic Gram positive cocci in chains and pairschains and pairs

Gray-white variable colony on BAPGray-white variable colony on BAP No exotoxinNo exotoxin

Virulence FactorsVirulence Factors

Dextran exopolysaccharide glycocalx:Dextran exopolysaccharide glycocalx:• Provides means of adherence to defective hearts valvesProvides means of adherence to defective hearts valves• May block the action of antibioticsMay block the action of antibiotics

Lipoteichoic Acid (LTA): mediates adhesion to Lipoteichoic Acid (LTA): mediates adhesion to fibronectin in clots on defective heart valvesfibronectin in clots on defective heart valves

Glucan: Polysaccharides made by Glucan: Polysaccharides made by S.mutans S.mutans from from sucrosesucrose in the mouth , they provide a mean of in the mouth , they provide a mean of attachement to teeth enamel.attachement to teeth enamel.

Other Acids: Made by Other Acids: Made by S.mutans S.mutans from fermentation of from fermentation of sugars in the mouth contributed to tooth decaysugars in the mouth contributed to tooth decay

Example of A biofilmExample of A biofilm Formation of dental plaque by Formation of dental plaque by Streptococcus Streptococcus

mutansmutans• bacteria adhere to the tooth by a protein on the cell bacteria adhere to the tooth by a protein on the cell

surface, grow and synthesize a dextran capsule surface, grow and synthesize a dextran capsule • binds the bacteria to the enamel and forms a binds the bacteria to the enamel and forms a

biofilm 300-500 cells of thicknessbiofilm 300-500 cells of thickness• bacteria can cleave sucrose to glucose + fructosebacteria can cleave sucrose to glucose + fructose• glucose is polymerized into an extracellular glucose is polymerized into an extracellular

dextran polymer that cements the bacteria to tooth dextran polymer that cements the bacteria to tooth enamel and becomes the matrix of plaqueenamel and becomes the matrix of plaque

• this dextran slime can be depolymerized to glucose this dextran slime can be depolymerized to glucose for use as a carbon source, resulting in the for use as a carbon source, resulting in the production of lactic acid within the plaque that production of lactic acid within the plaque that decalcifies the enamel and leads to dental cariesdecalcifies the enamel and leads to dental caries

Laboratory testsLaboratory tests

Catalase : -veCatalase : -ve Hemolysis: AlphaHemolysis: Alpha 6.5% NaCl : No growth 6.5% NaCl : No growth Bile Esculin : -ve Bile Esculin : -ve Bile Solubility : -veBile Solubility : -ve Optochin : ResistantOptochin : Resistant CAMP Test : -veCAMP Test : -ve Lancefield ; Non (CHO C)Lancefield ; Non (CHO C)

ClinicalClinical Normal Flora in the Oropharynx ,GIT and GUT, enters blood Normal Flora in the Oropharynx ,GIT and GUT, enters blood

after dental work or due to poor oral hygiene after dental work or due to poor oral hygiene Bacteremia : Bacteremia : S.mutan .S.mutan . Sub-acute Endocarditis: most common cause , after bacteremia Sub-acute Endocarditis: most common cause , after bacteremia

due to dental work and infect maily abnormal valve or due to dental work and infect maily abnormal valve or prosthetic valve , rarely normal valves. It is fatal if not treated.prosthetic valve , rarely normal valves. It is fatal if not treated.

Dental caries: see above.Dental caries: see above. Lysis of bacteria by serum enzyme and lysosomal enzyme.Lysis of bacteria by serum enzyme and lysosomal enzyme. No vaccine availableNo vaccine available

TreatmentTreatment

Dental prophylaxis : One hour before Dental prophylaxis : One hour before procedure in case of abnormal valve with procedure in case of abnormal valve with ampicillinampicillin

Ampicillin +/- aminoglycoside in case of Ampicillin +/- aminoglycoside in case of endocarditisendocarditis

Vancomycin in penicillin allergic patientVancomycin in penicillin allergic patient

TreatmentTreatment

VGS, NVS, VGS, NVS, sreptococcussreptococcus

Native valveNative valve prosthetic valve prosthetic valve

MIC <0.1 ug/mIMIC <0.1 ug/mI PenGPenG PenG 6wk PenG 6wk +Gentamicin 2wk +Gentamicin 2wk

MIC >0.1 —0.5 ug/mIMIC >0.1 —0.5 ug/mI PenG 4wkPenG 4wk +Gentamicin +Gentamicin 2wk2wk

PenG 6wk + PenG 6wk + Gentamicin 4wk Gentamicin 4wk

EnterococcusEnterococcus

Fecal strepFecal strep separated genus/by molecular separated genus/by molecular Enterococcus FaecalisEnterococcus Faecalis and and E.Faecium E.Faecium Extracellular Aerobic Gram positive cocci single in Extracellular Aerobic Gram positive cocci single in

chains or pairs chains or pairs Gray –white or variable colony on BAPGray –white or variable colony on BAP Non Motile, Not capsulated, no Glycocalx and No Non Motile, Not capsulated, no Glycocalx and No

ExotoxinExotoxin Adhesion to defective heart valves and urinary tractAdhesion to defective heart valves and urinary tract Antibiotics resistantAntibiotics resistant

Laboratory TestsLaboratory Tests

Catalase : -veCatalase : -ve Hemolysis: Alpha, Beta or GammaHemolysis: Alpha, Beta or Gamma 6.5% NaCl : Growth 6.5% NaCl : Growth PYR : + ve and LAP : +ve PYR : + ve and LAP : +ve Growth at 45 Growth at 45 ooCC 40% Bile Salt: +ve 40% Bile Salt: +ve Bile Esculin : +ve Bile Esculin : +ve CAMP Test : -veCAMP Test : -ve Lancefield ; group D (CHO C)Lancefield ; group D (CHO C)

Source and TransmissionSource and Transmission

Normal Flora in GIT in humanNormal Flora in GIT in human Harsh conditionHarsh condition Abiquitous / Abiquitous /

soil,water,plants, GIT, GU humansoil,water,plants, GIT, GU human 15 Spp/E.faecalis15 Spp/E.faecalis80-90% of clinical isolate80-90% of clinical isolate Bacteremia after urinary tract infection, Intra-Bacteremia after urinary tract infection, Intra-

abdominal route or via indwelling cathetersabdominal route or via indwelling catheters Exogenous acquisition in the hospital Exogenous acquisition in the hospital

(nosocomial) (nosocomial)

ClinicalClinical

Urinary tract infection (UTI)Urinary tract infection (UTI) : Nosocomial, : Nosocomial, upper and lower UTIupper and lower UTI

BacteremiaBacteremia: From UTI , Intra-abdominal : From UTI , Intra-abdominal infection or indwelling catheter ( Intravenous infection or indwelling catheter ( Intravenous or hemodialysis) , common in I’C patientsor hemodialysis) , common in I’C patients

Sub-Acute Endocarditis : Sub-Acute Endocarditis : After bacteremia, After bacteremia, affects abnormal or prosthetic valves , it is affects abnormal or prosthetic valves , it is fatal if not treatedfatal if not treated

Host defense and immunity is unknownHost defense and immunity is unknown

Treatment and preventionTreatment and prevention

AmpicillinAmpicillin in case of UTI by in case of UTI by E.faecalisE.faecalis VancomycinVancomycin in case of in case of E.faecium E.faecium Ampicillin or Vancomycin + gentamicineAmpicillin or Vancomycin + gentamicine in in

case of endocarditiscase of endocarditis Streptogramin or LinazolidStreptogramin or Linazolid in case of in case of

Vancomycin Resistant Enterococcus (VRE) Vancomycin Resistant Enterococcus (VRE) Infection control measures in case of VRE Infection control measures in case of VRE

outbreakoutbreak No vaccine availableNo vaccine available

EndocarditisEndocarditis

Enterococcus, Enterococcus, Native valveNative valve Prosthetic valve Prosthetic valve

MIC >0.5 ug/ul, MIC >0.5 ug/ul, PenG or Amp PenG or Amp plus Gent for plus Gent for 4-6 4-6 wkwk

total total 6 wk6 wk

Streptococcus Bovis Streptococcus Bovis ( ( Streptococcus gallolyticus NEW NAME)Streptococcus gallolyticus NEW NAME)

Group D streptococciGroup D streptococci Aerobic extracellular Gram positive cocci in Aerobic extracellular Gram positive cocci in

chains or pairschains or pairs Gray-white colony on BAPGray-white colony on BAP Non-Motile, Non-Capsulated and GlycocalyxNon-Motile, Non-Capsulated and Glycocalyx No Valulant factorsNo Valulant factors

Laboratory TestsLaboratory Tests Catalase : -veCatalase : -ve Hemolysis: Alpha, Beta or GammaHemolysis: Alpha, Beta or Gamma 6.5% NaCl : No growth (opposite to enterococcus)6.5% NaCl : No growth (opposite to enterococcus) PYR : -ve (opposite to enterococcus)PYR : -ve (opposite to enterococcus) No Growth at 45 No Growth at 45 ooC (opposite to enterococcus)C (opposite to enterococcus) 40% Bile Salt: +ve (opposite to viridans)40% Bile Salt: +ve (opposite to viridans) Bile Esculin : +ve (opposite to viridans)Bile Esculin : +ve (opposite to viridans) CAMP Test : -veCAMP Test : -ve Lancefield ; group D (CHO C)Lancefield ; group D (CHO C) Two biotypes I &IITwo biotypes I &II

ClinicalClinical Normal Flora in GIT Normal Flora in GIT Infection after diruption of GI epithelium in case of Infection after diruption of GI epithelium in case of

malignancymalignancy Bacteremia from GITBacteremia from GIT Endocarditis after bacteremia, fatal if not treatedEndocarditis after bacteremia, fatal if not treated Colonic cancer has strong association with Colonic cancer has strong association with S.bovis S.bovis

bacteremiabacteremia IgA, IgG and PMNsIgA, IgG and PMNs Treatment penicillin or vancomycin( rarely resistant Treatment penicillin or vancomycin( rarely resistant

to vancomycin)to vancomycin) No vaccination availableNo vaccination available

SummarySummary

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