LAB WORK
  • Gram +, beta-hemolytic (complete hemolysis)

TREATMENT
  • Penicillins are drug of choice since all strains are susceptible, cultures may not show sensitivity result for this reason
  • Second line:
    • Cefazolin (all cephalosporins)
    • Vancomycin
    • Fluoroquinolones
  • Agents with variable activity (avoid due to resistance concerns):
    • Tetracyclines
    • Clindamycin
      • Group A toxic shock syndrome: clindamycin has been added to penicillin-based treatment, it may inactivate toxins
    • Bactrim
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CLINICAL NOTES
  • Common human pathogen (normal flora in up to 15% of people)
  • Toxin-producing strains may be involved in severe, rapidly-worsening infections (e.g., necrotizing fasciitis, myositis, and toxic shock syndrome)
  • Post-infection sequelae
    • Acute rheumatic fever
      • Group A strep has M proteins as a virulence factor; anti-M protein antibodies' cross-reaction with heart muscle is the underlying mechanism for rheumatic fever
    • Acute glomerulonephritis
      • Immune-mediated, may occur 1-3 weeks post infection