Streptococcus pyogenes (Groups A, B, C, G, F)

Background:

———————————————————
Streptococci
———————————————————
>Streptococcus anginosus group (formerly Streptococcus milleri)
     1] Streptococcus intermedius
     2] Streptococcus anginosus
     3] Streptococcus constellatus
>Streptococcus pneumoniae
>Streptobacillus moniliformis
>Streptococcus pyogenes (Groups A, B, C, G, F)led
>Streptococcus agalactiae  (Group B streptococcus)

Streptococcus pyogenes:

  • Spherical, Gram-positive bacterium.
  • 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”).

 

top of page

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.

  1. Amoxicillin 500mg orally three times daily or Ampicillin 2 grams IVPB every 4-6 hours
  2. Penicillin G 2-4 million units IV q4-6h or Penicillin VK 500mg orally every 6 hours
  3. Clindamycin  600mg IV every 6 or 8 hours or 300mg orally four times daily 
  4. Ampicillin-sulbactam 1.5 – 3 grams IV q6h
  5. Ceftriaxone 1-2 grams IV q24h
  6. Others

Disclaimer

The authors make no claims of the accuracy of the information contained herein; and these suggested doses are not a substitute for clinical judgment. Neither GlobalRPh Inc. nor any other party involved in the preparation of this program shall be liable for any special, consequential, or exemplary damages resulting in whole or part from any user’s use of or reliance upon this material.PLEASE READ THE DISCLAIMER CAREFULLY BEFORE ACCESSING OR USING THIS SITE. BY ACCESSING OR USING THIS SITE, YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS SET FORTH IN THE DISCLAIMER. Read the disclaimer