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STAPHYLOCCOCUSSTAPHYLOCCOCUS

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Gram positiveGram positive

GrapelikeGrapelike

Few are capsulatedFew are capsulatedAerobic/facultative anaerobicAerobic/facultative anaerobic

Grows best in 35 CGrows best in 35 C

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As a saprohrophyteAs a saprohrophyte

SkinSkin

Mucous membraneMucous membrane

NoseNoseMouthMouth

intestineintestine

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PathologyPathology

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Abscess formation: localized inflammatory reaction that undergoesAbscess formation: localized inflammatory reaction that undergoessuppurationsuppuration

Impetigo: painless ulcers in the lower extremities characterized byImpetigo: painless ulcers in the lower extremities characterized byhoney colored crusts ( less than 10% )honey colored crusts ( less than 10% )

Scalded Skin Syndrome (Ritters disease): SSS toxin destroys theScalded Skin Syndrome (Ritters disease): SSS toxin destroys the

basal lamina of the skin resulting in generalized exfoliativebasal lamina of the skin resulting in generalized exfoliativedermatitisdermatitis

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Pneumonia: in immunocompromised individualsPneumonia: in immunocompromised individuals Osteomyelitis: may lead to meningitis and endocarditisOsteomyelitis: may lead to meningitis and endocarditis Ptomaine poisoning (Staphylococcal food poisoning):Ptomaine poisoning (Staphylococcal food poisoning):

Incubation period of 1-8 hours after eating contaminated foodIncubation period of 1-8 hours after eating contaminated food S/Sx: nausea, vomiting, diarrheaS/Sx: nausea, vomiting, diarrhea Due to ingestion of preformed enterotoxin specially in pastries, eggDue to ingestion of preformed enterotoxin specially in pastries, egg

and meat-based foodstuffand meat-based foodstuff

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Toxic Shock SyndromeToxic Shock Syndrome Abrupt onset of high fever, vomiting, diarrhea, myalgia,Abrupt onset of high fever, vomiting, diarrhea, myalgia,

scarletiniform rash in the abdomen, later leads to hypotension,scarletiniform rash in the abdomen, later leads to hypotension,cardiac and renal failurecardiac and renal failure

Commonly associated w/ prolonged use of tampoonsCommonly associated w/ prolonged use of tampoons

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Pathogenic determinantsPathogenic determinants

CapsuleCapsule

EnzymesEnzymes

coagulase- clotting of plasmacoagulase- clotting of plasma

Hyaluronidase- Duran reynal factorHyaluronidase- Duran reynal factor

Staphylokinase- fibrinolytic activityStaphylokinase- fibrinolytic activityNucleaseNuclease

LipaseLipase

penicillinasepenicillinase

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toxinstoxins

ExotoxinExotoxinAlphaAlpha

BetaBeta

deltadelta

LeukocidinLeukocidin

EnterotoxinEnterotoxinExfoliative toxinExfoliative toxin

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OsteomyelitisOsteomyelitis

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Scalded skin syndromeScalded skin syndrome

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FuruncleFuruncle

AcuteAcuteStaph. aureusStaph. aureusSmall, follicularSmall, follicular

noduler -- Pustule--noduler -- Pustule--necrotic--dischargenecrotic--discharge

puspusPainfulPainful

ConstitutionalConstitutionalsymptomssymptomsHeals with scarHeals with scar

Age: AdultAge: Adult Site: Neck, Wrist, Waist,Site: Neck, Wrist, Waist,

Buttocks, FaceButtocks, Face

Complication: CavernousComplication: Cavernous

Sinus thrombosis,Sinus thrombosis,(upper lip & check);(upper lip & check);

Septicemia (malnutrition)Septicemia (malnutrition)

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FuruncleFuruncle

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CarbuncleCarbuncle

Extensive infection of aExtensive infection of a

group of contagiousgroup of contagious

folliclesfollicles Staph. aureusStaph. aureus Middle or old ageMiddle or old age Predisposing factorsPredisposing factors

DiabetesDiabetesMalnutritionMalnutrition Severe generalizedSevere generalized

dermatosesdermatoses During prolonged steroidDuring prolonged steroid

therapytherapy

Painful, hard lumpPainful, hard lump Suppuration beginsSuppuration begins

after 5-7 daysafter 5-7 days

Pus discharge fromPus discharge from

multiple follicularmultiple follicular

orificiesorificies Necrosis of interveningNecrosis of intervening

skinskin Large deep ulcerLarge deep ulcer ConstitutionalConstitutional

symptomssymptoms

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CarbuncleCarbuncle

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Staphylococcal scalded skinStaphylococcal scalded skin

SyndromeSyndrome Exotoxin ofExotoxin of

staphylococcusstaphylococcus(exfoliative toxin/(exfoliative toxin/epidermolytic toxin)epidermolytic toxin)

Infants and childrenInfants and children Tender red skinTender red skin Denuded skinDenuded skin Heals 7 - 14 dayHeals 7 - 14 day Dont grow staph. fromDont grow staph. from

blister fluidblister fluid

Complication 2%Complication 2% CellulitisCellulitis PneumoniaPneumonia

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Toxic Shock SyndromeToxic Shock Syndrome

Toxic shockToxic shock

syndrome toxinsyndrome toxin (TSST-1)(TSST-1)

super antigensuper antigenTampon or infectedTampon or infected

wound,wound,

TSST-1 enters bloodTSST-1 enters blood

stream and causestream and causefever, rash, exfoliationfever, rash, exfoliation

of skin and shockof skin and shock

(death rate 3%)(death rate 3%)

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Staphylococcus epidermidisStaphylococcus epidermidis

S. albusS. albus

Normal flora of the skinNormal flora of the skin

Stitch abscess blepharitisStitch abscess blepharitis

Coagulase positiveCoagulase positiveNon hemolyticNon hemolytic

Porcelain whitePorcelain white

May cause infection associated with prostheticMay cause infection associated with prostheticdevicesdevices

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Staphylococcus saphrophyticusStaphylococcus saphrophyticus

May cause UTI among sexually activeMay cause UTI among sexually active

young womenyoung women

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Other StaphylococciOther Staphylococci

Coagulase-negative staphylococcus; frequently involved inCoagulase-negative staphylococcus; frequently involved innosocomial and opportunistic infectionsnosocomial and opportunistic infections

S. hominisS. hominis lives around apocrine sweat glands lives around apocrine sweat glands

S. capitisS. capitis live on scalp, face, external ear live on scalp, face, external ear

All 3 may cause wound infections by penetrating throughAll 3 may cause wound infections by penetrating throughbroken skin.broken skin.

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testtest

Catalase testCatalase test

coagulase testcoagulase test

Staining procedureStaining procedure