Cause of group A streptococcal infections (displays streptococcal group A antigen on its cell wall).
S. pyogenes typically produces large zones of beta-hemolysis when cultured on blood agar plates.
Streptococci are catalase-negative.
Has an incubation period of approximately 1–3 days.
It is estimated that there are more than 700 million infections world wide each year and over 650,000 cases of severe, invasive infections that have a mortality rate of 25%.
S. pyogenes is the cause of many important human diseases, ranging from mild superficial skin infections to life-threatening systemic diseases.
Infections typically begin in the throat or skin. Examples of mild S. pyogenes infections include pharyngitis (“strep throat”) and localized skin infection (“impetigo”).
Therapy:
Important considerations: The choice of an agent should be based on local antimicrobial sensitivities, site of infection, cost, and comorbid conditions. Generally, the most common agents/regimens are listed first. Listed dosages may need to be adjusted for renal dysfunction.
Amoxicillin 500mg orally three times daily or Ampicillin 2 grams IVPB every 4-6 hours