Streptococcus anginosus group: Difference between revisions

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Streptococcus anginosus group
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== Background ==
==Background==


=== 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]] [[Cellular shape::coccus|cocci]] within the [[viridans group streptococci]]
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**Failure to ferment sorbitol
**Failure to ferment sorbitol


== Clinical Manifestations ==
==Clinical Manifestations==


* Tendency to form [[Abscess|abscesses]], unlike other [[streptococci]], which can be polymicrobial with [[anaerobes]] and [[Enterobacterales]]
*Tendency to form [[Abscess|abscesses]], unlike other [[streptococci]], which can be polymicrobial with [[anaerobes]] and [[Enterobacterales]]
* Infections can range in severity, and include [[pharyngitis]], [[dental abscess]], [[skin and soft tissue infection]], [[pneumonia]], [[empyema]], [[lung abscess]], [[brain abscess]], [[liver abscess]], and [[kidney abscess]]
*Infections can range in severity, and include [[pharyngitis]], [[dental abscess]], [[skin and soft tissue infection]], [[pneumonia]], [[empyema]], [[lung abscess]], [[brain abscess]], [[liver abscess]], and [[kidney abscess]]


== Investigations ==
==Investigations==


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


== Management ==
==Management==


*Typically treated with [[Is treated by::ceftriaxone]] or other third-generation [[Cephalosporins|cephalosporin]] pending susceptibilities
*Typically treated with [[Is treated by::ceftriaxone]] or other third-generation [[Cephalosporins|cephalosporin]] pending susceptibilities
*If found in an abscess, should be considered polymicrobial and treated with concomitant [[metronidazole]]
*20-30% clindamycin resistance
*Clindamycin resistance is high, approximately 20-30%
*If found in an abscess, should be considered polymicrobial and treated with


{{DISPLAYTITLE:''Streptococcus anginosus'' group}}
{{DISPLAYTITLE:''Streptococcus anginosus'' group}}

Revision as of 22:37, 13 September 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%