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Microbiology, Epidemiology, and Pathogenesis
Botulism is a paralytic disease caused by neurotoxins elaborated by Clostridium botulinum, an anaerobic spore-forming gram-positive bacterium, as well as a few other toxigenic Clostridium spp.
- Botulism is caused by the toxin’s inhibition of acetylcholine release at the neuromuscular junction through an enzymatic mechanism.
- C. botulinum toxin types A, B, E, and (rarely) F cause human disease, with toxin type A causing the most severe syndrome.
- Toxin type E is associated with foods of aquatic origin.
- Transmission is usually due to consumption of foods contaminated with botulinum toxin, but contamination of wounds with spores also can result in disease.
- Most U.S. food-borne cases (average, 23 cases per year) are associated with home-canned food.
- Infant botulism results from toxigenic clostridial colonization of the intestine of children <1 year of age and is the most common form of the disease in the United States, with ~80–100 cases reported annually.
- Toxin is heat-labile, and spores are heat-resistant; these properties underscore the importance of properly heating foods.
- Botulinum toxin is among the most toxic substances known and thus is of concern as a potential weapon of bioterrorism.