What is the name of the bacterial toxin that causes botulism?

The bacterial toxin that causes botulism is botulinum toxin. It is a powerful neurotoxic protein made mainly by Clostridium botulinum and, in some cases, related Clostridium species.

Botulinum toxin causes illness by preventing nerve endings from releasing acetylcholine, the chemical signal that normally tells muscles to contract. The resulting flaccid paralysis can begin with blurred vision, difficulty swallowing, and muscle weakness, and may progress to respiratory failure.

Botulism has several forms. Foodborne botulism follows ingestion of preformed toxin, often from improperly canned foods. Infant botulism occurs when spores grow in an infant’s intestine, while wound botulism develops when spores infect oxygen-poor tissue. The disease is not spread directly from person to person.

The toxin’s history also explains a common mix-up: botulinum toxin is dangerous in tiny quantities, yet carefully purified and diluted preparations are used medically for muscle spasticity, migraine, and other conditions. “Botox” is a brand name associated with one commercial preparation, not the toxin’s scientific name.