-Hemolytic Streptococci Ali Somily MD,FRCPC,D(ABMM)

Introduction Grouped by either A.phenotypic Or B.Genotypic Hemolysis(,ß or ) Lancefield antigen Cell wall CHO A,B,C,D,Fand G ect Or B.Genotypic G+ve cocci in chains and/or pairs Colonize MM(Resp.,GIT& GUT) Catalase –ve Ferment CHOlactic acid

&ß Hemolysis

Lancefield Agglutination

-Hemolytic Streptococci Partial hemolysis of blood Green zoon around the colony Examples: S.Pneumoniae S.Viridans S.Bovis

STREPTOCOCCUS PNEUMONIAE

STREPTOCOCCUS PNEUMONIAE VIRULANCE VACTORS Capsule Autolysin Pneumolysin CLINICAL PRESENTATION NF Resp.20-40%/pharynx Inhalation/droplets

CLINICAL PRESENTATION Primary infection CAPalveoli Blood Endocarditis Meningitis Localized Sinusitis O.M Secondary Infection Non-capsulated Opportunistic infection Lungs only Impair or poor ciliary activity Viral, Smoking, dust Risk factor Hyposplenism Splenectomy Asplenia Sickle Cell Diseases Liver disease Hypogammaglobinaemia Alcoholism Cigarette smoking Malnutrition

Diagnosis Blood,CSF,Sputum& swab/aspirate DIRECT SMEAR G+ve diplococci Lancet shape Capsulated halo (antiphagocytic)/pathogenic

Diagnosis Quellung test(AB’s swelling of capsule)

STREPTOCOCCUS PNEUMONIAE CULTURE BAP; 5-10%CO2 -hemolytic Mucoid (capsule)SR Concave (punched out/collapse) IDENTIFICATION Bile solubility (NaDC) Optochin S (disk 5g&6mmzoon>=14 mm) 80 serotype(vaccine) capsular structure

Treatment &Prevention TTT Penicillin(↑R recently)PBP Ceftriaxon +/-Vancomycin or Rifampicin Vaccination Polsaccharide capsule Conjugate vaccine Indication Children SCD Splenectomised patient HIV Elderly Cardiopulmonary and renal diseases

VIRIDANS STREPTOCOCCI

Grouping of viridans streptococci Mitis Mutans Salvarius Angionosis Mitis( hem.) 6 species Endocarditis S.gordonii S.sanguis Hard, adherent & smooth (dextran) 2.Mutans ( hem mostly) Dental caries 3.Salvarius(  hem  ) 3 species Hard ,large, mucoid colony (extracellular polsaccharide) 4.Angionosis (& ß hem.co2 or anaer.) i.e milleri Abscesses body cavity Butterscotch sweet odor (diacetyl) S.angionosis S.intermedius  ,group F S.constellatus ß

VIRIDANS STREPTOCOCCI CLINCAL PRESENTATION NF (GIT,UGT&Oral cavity) Opportunistic organisms Dental caries Endocarditis

Example of a biofilm Formation of dental plaque by Streptococcus mutans bacteria adhere to the tooth by a protein on the cell surface, grow and synthesize a dextran capsule binds the bacteria to the enamel and forms a biofilm 300-500 cells of thickness bacteria can cleave sucrose to glucose + fructose glucose is polymerized into an extracellular dextran polymer that cements the bacteria to tooth enamel and becomes the matrix of plaque this dextran slime can be depolymerized to glucose for use as a carbon source, resulting in the production of lactic acid within the plaque that decalcifies the enamel and leads to dental caries

Endocarditis Damage ,prosthetic valve SBE Predisposing factor RHD CHD Mitral valve prolapse Degenerative H diseases PV Pathogenesis Dextran adhere to the damaged valve vegetation(fibrin,bacteria & platelets) Symptoms Fever Murmurs Immunological manifestations O,P,S SBE 2-5 Wks Diagnosis Blood culture ECHO

Treatment VGS, NVS, sreptococcus Native valve prosthetic valve PenG MIC <0.1 ug/mI PenG PenG 6wk +Gentamicin 2wk MIC >0.1 —0.5 ug/mI PenG 4wk +Gentamicin 2wk PenG 6wk + Gentamicin 4wk

Microbiology DIRECT SMEAR CULTURE IDENTIFICATION G+ve cocci in chains Can be  OR  rarely ß hemolytic Most lack distinct LA IDENTIFICATION Urea VP( acetoin production) Arginine hydrolysis Esculin hydrolysis CHO ferementation

Enterococcus

Introduction Fecal strep separated genus/by molecular Harsh conditionAbiquitous/soil,water,plants, GIT, GU human 15 Spp/E.faecalis80-90% of clinical isolate Colonization/infection

CLINICAL PRESENTATION NC BACTEREMIA 1/3 NC UTI 16% WOUND ENDOCARDITIS CNS PNEUMONIA (rare) ELDERLY I’C TTT Vancomycin VRE (Van A,B&C ect) Plasmid/chromosomal High/low level VDE Direct smear Short chain/pairs/coccobaccilary

CULTURE IDENTIFICATION Facultative anaerobs  OR  hemolysis Catalase weak +ve Group D IDENTIFICATION Growth B/W 10-42 Co 6.5% NaCl Esculin hydrolysis(40%)bile salt Pyrrolidonyl arylamidase(PYR)+ve Leucine arylamidase(LAP)+ve Motility ,Pigmentation,arabinose and methyl --D-glucopyranoside

Bile esculin All Group D Enterococcus S.Bovis

PYR/PYR-LAP

Endocarditis Native valve Prosthetic valve MIC >0.5 ug/ul, Enterococcus, Native valve Prosthetic valve MIC >0.5 ug/ul, PenG or Amp plus Gent for 4-6 wk total 6 wk

BOVIS GROUP New Name Streptococcus gallolyticus (Group D Streptococci)

BOVIS GROUP CLINICAL DIRECT SMEAR Human intestine and animals Endocarditic Septicemia Link to colon cancer Stool isolation Two biotypes I&II Mannitol and glucan I DIRECT SMEAR G+ve cocci in chains

Differed from viridans CULTURE  OR  on BAP IDENTIFICATION LG group D Differed from viridans Growth in 40% bile salt Hydrolyze esculin IDENTIFICATION LG group D Differed from viridans Growth in 40% bile salt Hydrolyze esculin No sorbitol fermentation Mannitol and inulin & starch ferm.

How you differentiate S. bovis from enterococcus? Unable to grow in 45 Co 6.5% salt @ 37dC PYR –ve S to penicillin and cephalosporins R to vancomycin(rare) Enterococcus Able to grow in 45 Co 6.5% salt @ 37Co PYR +ve S to ampicillin

Summary