Endotoxins vs. Exotoxins

  1. Organism
    • Exotoxin: Almost all Gram-positive
    • Endotoxin: Almost all Gram-negative
  2. Location
    • Exotoxin: Extracellular, excreted by living organisms
    • Endotoxin: Part of pathogen cell wall, released when cell dies
  3. Chemistry
    • Exotoxin: Polypeptide
    • Endotoxin: Lipopolysaccharide complex
  4. Stability
    • Exotoxin: Unstable; denatured above 60 degrees C
    • Endotoxin: Stable; can withstand 60 degrees C for hours
  5. Toxicity
    • Exotoxin: Among the most powerful toxins known (100 to 1 million times more lethal than strychnine)
    • Endotoxin: Weak, but fatal in high doses
  6. Effects
    • Exotoxin: Highly specific, several types
    • Endotoxin: Nonspecific; local reactions, such as fever, aches, and possible shock
  7. Fever production
    • Exotoxin: No
    • Endotoxin: Yes, rapid rise to very high fever
  8. Usefulness as antigen
    • Exotoxin: Very good, long-lasting immunity confered
    • Endotoxin: Weak, no immunity conferred
  9. Conversion to toxoid form
    • Exotoxin: Yes, by chemical treatment
    • Endotoxin: No
  10. Lethal dose
    • Exotoxin: Small
    • Endotoxin: Large
  11. Typical Infections Caused
    • Exotoxins: Botulism, gas gangrene, etanus, diptheria, cholera, plague, scarlet fever, staphylococcal food poisening
    • Endotoxins: Salmonellosis, typhoid fever, tularemia, meningococcal meningitis, endotoxic shock
Card Set
Endotoxins vs. Exotoxins
Endotoxins vs. Exotoxins