Streptococcus anginosus group: Difference between revisions

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Streptococcus anginosus group
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===Microbiology===
===Microbiology===


*Catalase [[Catalase::negative]], variably hemolytic [[Stain::Gram-positive]] [[Cellular shape::coccus|cocci]] within the [[viridans group streptococci]]
*Catalase [[Catalase::negative]], variably hemolytic [[Stain::Gram-positive]] [[Shape::coccus|cocci]] within the [[viridans group streptococci]]
*Contains ''Streptococcus anginosus'', ''Streptococcus constellatus'', and ''Streptococcus intermedius''
*Contains ''Streptococcus anginosus'', ''Streptococcus constellatus'', and ''Streptococcus intermedius''
**''S. anginosus'' has two subspecies: ''S. anginosus'' subsp. ''anginosus'' and ''S. anginosus'' subsp. ''whileyi''
**''S. anginosus'' has two subspecies: ''S. anginosus'' subsp. ''anginosus'' and ''S. anginosus'' subsp. ''whileyi''

Latest revision as of 18:25, 13 October 2020

Background

Microbiology

  • Catalase negative, variably hemolytic Gram-positive cocci within the viridans group streptococci
  • Contains Streptococcus anginosus, Streptococcus constellatus, and Streptococcus intermedius
    • S. anginosus has two subspecies: S. anginosus subsp. anginosus and S. anginosus subsp. whileyi
    • S. constellatus has three subspecies: S. constellatus subsp. constellatus, S. constellatus subsp. pharyngis, and S. constellatus subsp. viborgensis
  • Have a buttered popcorn smell on plate
  • Normal flora of oral cavity, throat, stool, and vagina
  • Identified using three rapid tests:
    • Voges-Proskaur (VP) test for acetoin production
    • Arginine hydrolysis
    • Failure to ferment sorbitol

Clinical Manifestations

Investigations

  • Presence of bacteremia without focus should prompt investigations to identify an occult abscess
  • The HANDOC score can assess need for echocardiography

Management

  • Typically treated with ceftriaxone or other third-generation cephalosporin pending susceptibilities
  • If found in an abscess, should be considered polymicrobial and treated with concomitant metronidazole
  • Clindamycin resistance is high, approximately 20-30%