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Organism
- Exotoxin: Almost all Gram-positive
- Endotoxin: Almost all Gram-negative
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Location
- Exotoxin: Extracellular, excreted by living organisms
- Endotoxin: Part of pathogen cell wall, released when cell dies
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Chemistry
- Exotoxin: Polypeptide
- Endotoxin: Lipopolysaccharide complex
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Stability
- Exotoxin: Unstable; denatured above 60 degrees C
- Endotoxin: Stable; can withstand 60 degrees C for hours
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Toxicity
- Exotoxin: Among the most powerful toxins known (100 to 1 million times more lethal than strychnine)
- Endotoxin: Weak, but fatal in high doses
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Effects
- Exotoxin: Highly specific, several types
- Endotoxin: Nonspecific; local reactions, such as fever, aches, and possible shock
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Fever production
- Exotoxin: No
- Endotoxin: Yes, rapid rise to very high fever
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Usefulness as antigen
- Exotoxin: Very good, long-lasting immunity confered
- Endotoxin: Weak, no immunity conferred
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Conversion to toxoid form
- Exotoxin: Yes, by chemical treatment
- Endotoxin: No
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Lethal dose
- Exotoxin: Small
- Endotoxin: Large
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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
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