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Staphylococcus

Hugh B. FackrellHugh B. Fackrell

Filename:Filename: staph.pptstaph.ppt

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OutlineOutline

DefinitionDefinition Extracellular productsExtracellular products DiseasesDiseases

suppurationsuppuration intoxicationsintoxications

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Staphylococcus

Gram +ve cocci in clustersGram +ve cocci in clusters catalase +vecatalase +ve facultative anaerobes facultative anaerobes sensitive to lysostaphin endopeptidasesensitive to lysostaphin endopeptidase resistant to lysozymeresistant to lysozyme ribitol or glyercol teichoic acidsribitol or glyercol teichoic acids

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Staphylococcus: structureStaphylococcus: structure

Gram positive spheres in grape-like clustersGram positive spheres in grape-like clusters Staphylo= grapesStaphylo= grapes Coccus = spheresCoccus = spheres

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Extracellular Products of StaphylococciExtracellular Products of Staphylococci

TOXINSTOXINS HemolysinsHemolysins Leucocidin ( Leukocidin)Leucocidin ( Leukocidin) EnterotoxinsEnterotoxins Exfoliative toxinsExfoliative toxins TSS toxinTSS toxin

ENZYMESENZYMES DNAseDNAse CoagulaseCoagulase FibrinolysinFibrinolysin LipasesLipases HyaluronidaseHyaluronidase

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Staphylococcus aureus produces the enzyme EndonucleaseStaphylococcus aureus produces the enzyme Endonuclease

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Staphlylococcal CoagulaseStaphlylococcal Coagulase

CoagulaseCoagulase: enzymes that cause clotting of : enzymes that cause clotting of blood plasmablood plasma

Measured by Measured by tube test (Free coagulase)tube test (Free coagulase) slide test (Bound coagulase)slide test (Bound coagulase)

Differentiation of Staphylococcal pathogens Differentiation of Staphylococcal pathogens S.aureusS.aureus coagulase positive coagulase positive

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Coagulase vs FibrinolysinCompeting EnzymesCoagulase vs FibrinolysinCompeting Enzymes

Coagulase: forms clotsCoagulase: forms clots Fibrinolysin: dissolves clotsFibrinolysin: dissolves clots

StaphylococcusStaphylococcus produces coagulase early produces coagulase earlyprotection against phagocytosisprotection against phagocytosis

When cell numbers high make fibrolysin When cell numbers high make fibrolysin break out of protectionbreak out of protection

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Resistant to bile saltsResistant to bile salts

Most strains grow in the Most strains grow in the presence of presence of 40% bile salts40% bile salts colonize intestinecolonize intestine

Most strains grown the Most strains grown the presence of presence of 15% NaCl15% NaCl Colonize the skinColonize the skin

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Major Staphylococcal PathogensMajor Staphylococcal Pathogens

Staphylococcus aureusStaphylococcus aureus infections & intoxicationsinfections & intoxications

Staphylococcus epidermidisStaphylococcus epidermidis ““stitch abcesses”stitch abcesses”

Staphylococcus saprophyticusStaphylococcus saprophyticus urinary tract infectionsurinary tract infections

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Staphylococci are NOT highly invasiveStaphylococci are NOT highly invasive

S aureusS aureus:50% are :50% are carrierscarriers found in nose areafound in nose area

S. epidermidis:S. epidermidis: universal universal present on skin present on skin

95% have immunity to 95% have immunity to StaphylococciStaphylococci

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Predisposing factorsPredisposing factors

Break in the skinBreak in the skin operations, burns, abrasionsoperations, burns, abrasions blockage of sweat glandsblockage of sweat glands

Chronic diseasesChronic diseases cancer, diabetes, cirrhosiscancer, diabetes, cirrhosis Staphylococcal pneumoniaStaphylococcal pneumonia

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Staphylococcal diseasesStaphylococcal diseases

Suppurative DiseasesSuppurative Diseases pus pus infiltration of WBC of polymorphonuclear infiltration of WBC of polymorphonuclear

leucocytesleucocytes Toxic poisoningsToxic poisonings

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Staphylococcal Suppurative DiseasesStaphylococcal Suppurative Diseases

boils, furuncles, carbunclesboils, furuncles, carbuncles wound infectionswound infections deep tissue abcessesdeep tissue abcesses osteomyelitisosteomyelitis pneumonia, empyemapneumonia, empyema

(intrapleural abcesses)(intrapleural abcesses) endocarditis, pericarditisendocarditis, pericarditis meningitismeningitis purulent arthritispurulent arthritis

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Staphylococcal mastitisStaphylococcal mastitis

Udder infections in dairy cattleUdder infections in dairy cattle Penicillin resistant StaphylococciPenicillin resistant Staphylococci Before antibioticsBefore antibiotics

Streptococcus group B & Group CStreptococcus group B & Group C

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Deep Tissue AbcessesDeep Tissue Abcesses

Often resist antibioticsOften resist antibiotics Surgical interventionSurgical intervention DrainageDrainage AntitoxinsAntitoxins

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Staphylococcal IntoxicationsStaphylococcal Intoxications

EnterotoxinEnterotoxin food poisoningfood poisoning

Toxic shock syndromeToxic shock syndrome HemolysinsHemolysins Epidermolytic toxinEpidermolytic toxin

““scalded skin syndrome”scalded skin syndrome” LeucocidinLeucocidin

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Staphylococcal HemolysinsStaphylococcal Hemolysins

Discovered because they Discovered because they Destroy RBCsDestroy RBCs

4 types4 types alpha: lethal cardiovascularalpha: lethal cardiovascular beta: “ hot cold” sphingomyelinasebeta: “ hot cold” sphingomyelinase

aggregates plateletsaggregates platelets

gamma: slightly dermonecrotic gamma: slightly dermonecrotic lethal in rabbitslethal in rabbits

delta: bee venomdelta: bee venom

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Platelet Damage by ToxinsPlatelet Damage by Toxins

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Staphylococcal Food PoisoningStaphylococcal Food Poisoning

Secreted proteinSecreted protein produced at room tempproduced at room temp produced aerobically and anaerobicallyproduced aerobically and anaerobically

milk & meat products excellent mediamilk & meat products excellent media Food handlers - carriersFood handlers - carriers

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Staphlylococcal Food Poisoning Signs & SymptomsStaphlylococcal Food Poisoning Signs & Symptoms

SymptomsSymptoms NauseaNausea Abdominal painAbdominal pain Projectile vomitingProjectile vomiting DiarrheaDiarrhea

Onset: average 3 hoursOnset: average 3 hours 1-6 hours 1-6 hours

Duration: 24 hours Duration: 24 hours

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EnterotoxinEnterotoxin

Several different formsSeveral different forms Protein 24,000 MWProtein 24,000 MW Resistant toResistant to

acidsacids proteases in digestive tractproteases in digestive tract boiling for 2 hoursboiling for 2 hours

Gene carried by lysogenic phageGene carried by lysogenic phage

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Toxic Shock SyndromeToxic Shock Syndrome

First reported 1980First reported 1980 young women during menstruationyoung women during menstruation tampons containing methacrylate supported tampons containing methacrylate supported

growth of growth of S. aureus S. aureus and production of and production of toxintoxin

Shock & death Shock & death

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The EndThe End