USMLE

Enterohemorrhagic E. Coli (EHEC)

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Bacteria - Gram Negative
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  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)
  • Enterohemorrhagic E. coli (EHEC)
    • Virulence Factors
      • O157:H7 is most common EHEC serotype in US
      • Produces Shiga-like toxin (verotoxin)
        • inactivates 60s ribosomal subunit, stopping protein production and leading to cell death
        • Major mediator of pathogenicity; toxin-mediated enterocyte death and intestinal hemorrhage
        • Similar to the mechanism of shiga toxin in Shigella spp.
          • Contrast vs. Shigella, where toxin plays minor role in pathogenesis
    • Transmission
      • Ingested via undercooked meat (beef)
        • unpasteurized milk, contaminated water are also sources
    • Presentation
      • Bloody Diarrhea
      • May be complicated by Hemolytic-uremic syndrome (HUS)
        • Triad of hemolytic anemia, thrombocytopenia, and kidney injury