Etiology

Botulism is caused by very powerful neurotoxins that are elaborated during the growth and multipli­cation of the bacterium C. botulinum. The bacte­rium, which exists in nature as a spore, multiplies and produces its toxin in oxygen-deprived or anaero­bic conditions, such as may occur in canned or her­metically sealed foods or unclean wounds.

C. botulinum are found naturally in soil and marine sediments, and thus may readily occur as normal contaminants of many vegetable and animal sources of food. The spores and their toxins are inactivated by boiling canned foods according to food industry specifications.

To date, seven immunologically distinct forms of botulinum toxins, labeled A through G, have been identified. Botulism in humans has generally been associated with A, B, E, or F toxins, whereas the C and D toxins have been identified in botulism out­breaks among various animal species, as shown in Table VIII.19.1.