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Streptococcus. Streptococcus. Low G+C Cocci pairs/chains FA Non motile, NSF Capnophiles Catalase (-) Peroxidase Hemolysins Lancefield Groups 18 antigens Cell wall reactivity. Lancefield Groups. Membrane Ag Groups A-H, K-V Group A Strep. pyogenes Group B Strep. agalactiae
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Streptococcus • Low G+C • Cocci pairs/chains • FA • Non motile, NSF • Capnophiles • Catalase (-) • Peroxidase • Hemolysins • Lancefield Groups • 18 antigens • Cell wall reactivity
Lancefield Groups • Membrane Ag • Groups A-H, K-V • Group A • Strep. pyogenes • Group B • Strep. agalactiae • Group C, F, G • Strep equisimilis • Strep zooepidemicus • Strep anguinosus • Group D • E. faecalis • Strep bovis • Strep equines • Group K • Strep salivarius • Viridans • Strep mutans • Strep mitis • Strep sanguis • Pneumococci
GAS: Strep pyogenes • Location • Skin, mm • Resp: pharynx • Pathogenicity • Adhesins • Protein F and S (fibronectin) • Lipoteichoic acid (LTA) • Immune evasion • Protein M • Binds to fibrinogen • Mimics CT/Muscle antigens • Capsule (hyaluronic acid) • Proteins • Streptolysins (leukocidins) • Function • Lyse formed elements • Beta hemolysis • Types • S = O2 stable • O = O2 labile
Strep pyogenes • Enzymes • Streptokinase • Break down clots • DNase B • depolymerize • Hyaluronidase • Proteases • C5a peptidase • Decrease chemotaxis • Toxins Exotoxins • Pyrogenic (A, B, C) • Superantigens • Increase immune cytokines • Promote fever • TSS like syndrome • Sepsis • M1 and M3 strains
Strep pyogenes diseases • Pharyngitis • Scarlet Fever (rash) • Skin • Pyoderma • Impetigo • Erysipelas • Cellulitis • Strep TSS • Necrotizing fasciitis • Myositis • Immune Mediated • Rheumatic fever • Glomerulonephritis
GBS: Strep agalactiae • Epidemiology • GI • Uritogenital • Pathogenicity • Capsule • Enzymes • Proteases • Hemolysins • Beta hemolysis • Hyaluronidase • Disease • Puerperal fever • Vaginitis • UTI • Endocarditis • Osteomyelitis • Newborn • Meningitis • Sepsis • Pneumonia CAMP test
Group C Strep • Strep equi • strangles • Strep equisimilis • pharyngitis • Strep anginosus • abscess
Viridans Streptococcus • Alpha hemolysis • No Lancefield groups • Diseases • Dental Caries • Endocarditis • Examples • Strep mitis • Strep mutans • Strep oralis • Strep sanguis • Strep salivarius (K)
Strep pneumoniae • Epidemiology • Mouth • Upper respiratory • Dz = lungs • Pathogenicity • Capsule • Protein A • Phosphorylcholine • Adhesins • Proteases • Protects from IgA • pneumolysins
Group D Strep • Examples • E. faecalis • E. faecium • S. bovis • S. equines • Location: GI • Tests • Gamma hemolysis • Salt tolerant • Bile tolerant • Pathogenicity • Bacterocins • Nosocomial