MedCompanion

Streptococcus pyogenes (Group A Strep)

GAS

Morphology: Beta-hemolytic, bacitracin-sensitive, PYR-positive.

StrepGramPosOther

Typical drugs

  1. #1Penicillin VK— Pharyngitis, mild SSTI.
  2. #2Cefazolin— Severe SSTI / nec fasc — pair with clindamycin.
  3. #3Clindamycin— Toxin suppression in nec fasc / TSS.

Empiric therapy when resistant

GAS remains uniformly PCN-susceptible. Macrolide resistance is the only common issue.

Resistance notes

100% penicillin-susceptible.

Common syndromes

Pearls

Cellulitis / erysipelas / necrotizing fasciitis (type II). Add clindamycin in invasive disease for toxin suppression (Eagle effect).

References

  • IDSA SSTI guidelines (2014)