Habitat: soil, water, intestines of animals and humans
Pathogenicity: Ingestion of the endospores usually does no harm in healthy adults (infants can develop infant botulism though, 30% of cases are associated with ingestion of endospores in honey!). However, under anaerobic conditions the organism produces the most powerful of all known exotoxins. This neurotoxin blocks the release of acetylcholine at synapses and prevents muscle contraction. Symptoms usually appear within 1-2 days. Patients experience nausea but no fever and then develop "flaccid paralysis" that may continue for up to 10 days. Death may result from respiratory and cardiac failure.
Botulinum toxin is very heat labile and is destroyed by most ordinary cooling mechanisms. It is not formed in acidic foods like tomatoes.
Treatment: supportive care; antibiotics are of little use because they are not effective against the toxin; antitoxins are usually administered but are only effective against toxin that is not already attached to nerve endings; recovery requires that the nerve endings regenerate.
*May also grow in wounds causing tetanus or gas gangrene.
Clostridium botulinum
