Botulin/botulinum toxin

BotuNsm toxin, botulin (botulinum toxin). Botulism is today a very infrequently occurring form of food poisoning by B., a metabolite of Clostridium botulinum. This rod-like bacterium develops anaerobically in conserved meat products, occasionally also in conserved vegetable or fish products as a result of an inadequate addition of salt or (in case of fish) of inadequate acidification. B. consists of a single polypeptide chain with a molecular mass of ca. 150000.7 types of... 

The partially-purified culture supernatant of C. botulinum strain 17784 catalyzes the ADP-ribosylation of two proteins in crude PC12 cell lysates (Fig. 1, lane 1). The band at 45 kDa coincides with actin, the substrate for botulinal C2 toxin (4,5). We caU the smaller product, of apparent molecular mass 21 kDa, p21.bot. The ADP-ribose-p21. bot band is sometimes broad, perhaps representing some heterogeneity. It represents a protein as it is digested by proteinase K and trypsin, but not by RNase. Labeling of p21.bot was blocked when lysates were fiirst incubated with unlabeled NAD before the p P]NAD, indicating that the ADP-ribosylation could be taken to completion (Fig. 1, lane 2). 

Botulin toxin may also act as an inhalation poison. This property has been reveled for both pure and progenitor (a complex with auxiliary proteins) toxins (Park and Simpson, 2003). C. botulinum and its toxin were included onto the list of high-priority agents - in the highest A category of agents that may potentially be used in bioterrorism (Khan et al., 2000 Sobel et al., 2002). 

Botulism also affects animals, where intoxication is caused by C. botulinum types C and D. A bovine disease visceral botulism was reported in Germany (Bohnel et al., 2001). It was caused by a long-lasting exposure to low quantities of botulin toxin that interfered with the neurological control of intestinal physiology. Visceral botulism in cows may pose a health risk for milk consumers, although to date there are no precise data on how serious the problem is (Cobb et al., 2002). 

Food stored in a proper way and in proper conditions is not a vehicle of C. botulinum. Unlike non-proteolytic strains, proteolytic strains will not grow in refrigeration temperatures. The number of spores in meat and poultry is rather low, much higher numbers are observed in fish. If stored at 3 to 5°C, vacuum-packed, not very sour meat products usually remain safe for consumers up to 21 days. Botulin toxin was not detected in raw rockfish fillets or red snapper homogenates after being stored for 21 days at 4°C. None of 1074 samples of commercially packed fresh fish stored for 12 days at 12°C contained botulin toxin (Lilly and Kautter, 1990). 

Sonnabend, O., Sonnabend, W., Heinzle, R., Sigrisf, T., Dimhofer, R., Krech, U. (1981). Isolation of Clostridium botulinum type G and identification of type G botulinal toxin in humans report of 5 sudden unexpected deaths. J. Infect. Dis. 143 22-7. 

Clostridium botulinum—A bacterium that excretes the toxin causing botulinism. 

Tacket CO, Rogawski MA. Botulinism. In Simpson LL, ed. Botulinum Neurotoxin and Tetanus Toxin. New York, NY Academic Press 1989 351-378. 

A. Botulism is caused by a heat-labile neurotoxin (botulin) produced by the bacteria Clostridium botulinum. Different strains of the bacterium produce seven distinct exotoxins A, B, C, D, E, F, and G types A, B, and E are most frequently involved in human disease. Botulin toxin irreversibly binds to cholinergic nerve terminals and prevents acetylcholine release from the axon. Severe muscle weakness results, and death is caused by respiratory failure. The toxin does not cross the blood-brain barrier. 

Botulinal toxin type A, crystalline Clostridium botulinum... 

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