USMLE

Yersinia enterocolitica

829 views
Bacteria - Gram Negative
  1. Neisseria spp: Overview
  2. Neisseria gonorrhoeae
  3. Neisseria meningitidis
  4. Haemophilus influenzae
  5. Bordetella pertussis
  6. Brucella
  7. Legionella pneumophila
  8. Pseudomonas aeruginosa: Overview
  9. Pseudomonas aeruginosa: Disease
  10. Salmonella Overview
  11. Salmonella typhi
  12. Salmonella enteritidis
  13. Shigella
  14. Yersinia enterocolitica
  15. Escherichia coli: Overview
  16. Enterohemorrhagic E. Coli (EHEC)
  17. Enterotoxigenic E. Coli (ETEC)
  18. Klebsiella pneumoniae
  19. Campylobacter jejuni
  20. Vibrio spp.
  21. Helicobacter pylori
  22. Borrelia burgdorferi (Lyme Disease)
  23. Leptospira interrogans
  24. Treponema pallidum: Overview
  25. Treponema pallidum: Diagnosis
  26. Congenital syphilis
  27. Chlamydia: Overview
  28. Chlamydia trachomatis
  29. Chlamydia pneumoniae vs. psittaci
  30. Rickettsia rickettsii
  31. Rickettsia typhi vs. prowazekii
  32. Anaplasma vs. Ehrlichia
  33. Coxiella burnetii (Q fever)

Yersinia enterocolitica 

  • Characteristics
    • Gram negative coccobacilli
    • Requires iron as an essential growth factor
      • Most strains lack efficient iron-uptake mechanisms
    • Grows in cold temperatures (refrigeration)
    • Many virulent strains may be calcium-dependent
  • Virulence factors
    • Enterotoxin
      • Activates guanylate cyclase, increasing cGMP
        • Intracellular increase in cGMP leads to watery diarrhea
  • Transmission
    • Oral ingestion of bacteria
      • pet feces
      • undercooked pork
      • may also appear in contaminated milk
  • Presentation
    • Watery diarrhea 
      • Invades GI mucosa and releases enterotoxin, causing watery diarrhea
    • Pseudoappendicitis 
      • Right lower abdominal pain due to growth and inflammation in mesenteric lymph nodes
      • appendix appears normal on CT 
  • Treatment
    • Antibiotics are not indicated for uncomplicated diarrhea
      • Supportive care (hydration) is standard of care
    • Severe cases may warrant antibiotics
      • Fluoroquinolones or TMP-SMX
      • Cephalosporins and gentamicin also used for sepsis