Microbiology Glossary
Virulence Factors
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Adherence factor: allows for better adherence to squamous epithelial cells of urogenital tract (not skin or mucosa) than other catalase neg staph.
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Alpha- hemolysin​: lyse rbcs & damages platelets and macrophages
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Beta- hemolysin: "hot-cold" lysin; acts on the plasma membrane of rbcs
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enhances Beta- hemolysis (make CAMP test work)​
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lethal to polynucleated WBCs
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contributes to invasiveness of S. aureus
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associated with severe cutaneous infections & necrotizing pnuemonia
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CAMP factor:
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Capsule: protects bacteria from phagocytosis
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Catalase: enzyme
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Coagulase: enzyme
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Cytolytic Toxins:​
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Includes alpha-, beta- and gamma- hemolysins
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Enterotoxin
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Exfoliative Toxin:
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Causes SSS & Ritter's Disease​
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Also causes bullous impetigo
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Gamma- hemolysin: only in association with Panton-Valentine leucocidin (PVL) in community acquired S. aureus
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Hemolysis:
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Hyaluronidase: also known as "spreading factor"
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an enzyme that ​dissolves the the hyaluronic acid found in connective tissues
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Lipase​​​: enhance spread of infection by working on lipids on skin & oil glands (sebaceous glands)
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M Protein:
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Protein A:
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Help bind the Fc portion of IgG preventing phagocytosis & negate protective effect of IgG​​
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Pyrogenic Exotoxins: (4 types)
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causes a spreading rash in Scarlet Fever​
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functions as a "super antigen"
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have the ability to stimulate a strong T-cell proliferation
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not all Strep A have one or all 4 of these
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Sialic Acid: in addition to a capsule, it help bacteria evade innate immune response of host
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Streptokinase: Lyses fibrin clots
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Streptolysin O:
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causes the beta hemolysis anaerobically​
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oxygen labile
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destroys platelets, WBCs, & RBCs
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Serologic test, ASO, tests for antibodies against it
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Streptolysin S