USMLE

Actinomyces

886 views
Bacteria - Gram Positive
  1. Staph aureus: Overview
  2. Staph aureus: Presentation
  3. Methicillin-Resistant Staph aureus (MRSA)
  4. Staph saprophyticus
  5. Strep pneumoniae: Overview
  6. Strep pneumoniae: Presentation
  7. Strep viridans
  8. Strep pyogenes: Overview
  9. Strep pyogenes: Presentation
  10. Strep agalactiae
  11. Strep bovis
  12. Enterococcus
  13. Bacillus anthracis
  14. Bacillus cereus
  15. Clostridium tetani
  16. Clostridium perfringens
  17. Clostridium botulinum
  18. Clostridium difficile
  19. Corynebacterium diphtheriae
  20. Listeria monocytogenes
  21. Nocardia
  22. Actinomyces

Actinomyces spp. 

  • Characteristics
    • Gram + rod in branching filaments
      • Forms long, branching filaments resembling fungi
      • Note: Nocardia is also a gram + filamentous rod
    • Produces yellow granules (“sulfur granules”)
      • Yellow bacterial aggregates bound together by proteins
      • Do not actually contain sulfur; named due to sulfur-like yellow color
    • Anaerobic
      • Contrast vs. Nocardia, which is aerobic
    • Does not stain acid-fast
      • Contrast vs. Nocardia, which stains acid-fast
  • Transmission
    • Infections usually follow dental work or oral trauma
      • Found in normal oral, reproductive, and GI flora
  • Presentation
    • Oral/facial abscesses
      • Presents as slow-growing firm abscesses in face/neck
      • Contrast vs. Nocardia, which usually presents with pulmonary infections 
    • Pelvic inflammatory disease
      • IUDs
  • Treatment
    • Penicillin
      • Tetracyclines may be used in patients with penicillin allergy
    • Surgical debridement