Streptococcus anginosus group


>Streptococcus anginosus group (formerly Streptococcus milleri)Led
   ‘Viridans streptococci’: 
     1] Streptococcus intermedius
     2] Streptococcus anginosus
     3] Streptococcus constellatus
>Streptococcus pneumoniae
>Streptobacillus moniliformis
>Streptococcus pyogenes (Groups A, B, C, G, F)
>Streptococcus agalactiae  (Group B streptococcus)

 Streptococcus anginosus group

  • -May be beta-hemolytic or nonhemolytic.
  • -Part of the human bacteria flora  (cultures obtained from mouth, throat, feces, and vagina, other). 
  • Several possible infections are possible based on the frequency of occurence.
  • -Several antimicrobial resistant strains exist.
  • Most strains studied have been shown to be largely susceptible to beta-lactam agents e.g. penicillins, cephalosporins
  • Sulfonamides have no activity.
  • Most strains are resistant to aminoglycosides


Top Of Page


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. Penicillin VK 500mg orally every 6 hours
  2. Penicillin G 2-4 million units IV q4-6h
  3. Cephalexin 500mg orally every 6 hours
  4. Ceftriaxone 1-2 grams IV q24h
  5. Vancomycin 1 gram  ivpb q12h (patient-specific dosing required)
Streptococcus anginosus group