• catalse⁺, coagulase⁺
• form β-hemolytic yellow colonies
• virulence
  • capsule
  • fibronectin bp (adhesin)
  • clumping factor
  • Protein A - binds Fc of IgG to prevent phagocytosis
  • catalase - counteract PMNs
  • coagulase - clotting
  • β hemolysins
    • α toxin - transmembrane channel
    • β - sphingomyelinase
    • γ - damage PMNs
    • δ - detergent
  • leukocidin
  • phospholipase
  • hyaluronidase
  • staphylokinase
  • β-lactamase
• exotoxins
  • TSST-1 SuperAg - TSS
  • exfolative SuperAg - scalded skin (plasmid)
  • enterotoxin SuperAg - food poisoning (phage)
• suppurative infections
  • foliculitis
  • furuncles
  • carbuncle
  • impetigo
  • surgical / burn wound
  • pneumonia
  • osteomyelitis
• Toxic infections
  • scalded skin syndrome
  • TSS: elevated IL-2 and TNF --> shock
  • Staph food poisoning (hydration)
• diagnosis
  • catalase / coagulase tests
  • growth on salt agar
  • antibiotic sensitivity

• coagulase^-, novobiocin sensitive
• grows on implanted devices and urinary tract, endocarditis in IV drug users
• treatment: vancomycin (lots of resistance)

• coagulase^-, novobiocin resistant
• infects urinary tract
• trimethoprim-sulfamethoxazole treatment

• Group A, β hemolytic, bacitracin sensitive
• virulence
  • M protein (antiphagocytic and antigenic)
  • streptolysin - PMNs
  • IgAase
  • C5a peptidase
  • Leukocidin, hyluronidase, streptokinase, DNAase
• exotoxins (SPEs --> SuperAg)
  • erythrogenic toxin --> scarlet fever rash
  • Toxic Streptoccocal Syndrome - TSS like
• localized infections
  • pharyngitis
• skin infections
  • impetigo
  • cellulitis/erysipelas
• invasive and focal infections
  • necrotizing faciitis
  • pneumonia
• toxigenic disease
  • scarlet fecer
  • toxic streptococcal syndrome
• post-infection sequelae
  • acute rheumatic fever
  • acute glomerulonephritis
• Treatment - penicillin

• Group B, β hemolytic, bacitratin resistant
• neonatal septis/meningitis; post-partum sepsis
• Penicillin during labor

• Group D, α/non-hemolytic, salt^-, escalin⁺
• normal GI flora
• endocarditis, bacteremias (esp. colon cancer)

Enterococcus faecalis

Enterococcus faecum

• Group D, α/non-hemolytic, salt⁺, escalin⁺
• normal GI, GU flora
• endocarditis, UTI, meningitis, wound infections, abdominal abcesses
• drug resistance - treated with penicillin (or vanco) + aminoglycoside

• α hemolytic, optochin sensitive, bile soluble
• normal flora of nasopharynnx
• antiphagocytic capsule in most virulent types
• lobar pneumonia, otitis media, meningitis
• treatment - penicillin, polyvalent vaccine for at-risk

• α hemolytic, optochin resistant
• dental caries, endocarditis
• treatment: penicillin (or vanco) + gentamycin