Sandbox WWC1: Difference between revisions

Botulinum Toxin (BTX) is produced by three species of obligate anaerobe bacterium, primarily ''Clostridium botulism'', but ''Clostridium baratii'' and ''Clostridium butyricum'' also produce the protein <ref>Hall JD, McCroskey LM, Pincomb BJ, Hatheway CL. Isolation of an organism resembling Clostridium baratii which produces type F botulinal toxin from an infant with botulism. J Clin Microbiol. 1985;21:654-655. 36. </ref> <ref>Aureli P, Fenicia L, Pasolini B, Gianfranceschi M, McCroskey LM, Hatheway CL. Two cases of type E infant botulism caused by neurotoxigenic Clostridium butyricum in Italy. J Infect Dis. 1986;154: 207-211. 37. </ref> <ref>Arnon SS. Botulism as an intestinal toxemia. In: Blaser MJ, Smith PD, Ravdin JI, Greenberg HB, Guerrant RL, eds. Infections of the Gastrointestinal Tract. New York, NY: Raven Press; 1995:257-271.</ref>. ''Clostridium botulism'' is commonly found in soil, marine sediments, and the gut of grazing animals <ref>Ward BQ, Carroll BJ, Garrett ES, GB Reese. Survey of the U.S. Gulf Coast for the presence of Clostridium botulinum. Appl Microbiol. 1967;15:629–636. 26.</ref> <ref> Smith LDS. The occurrence of Clostridium botulinum and Clostridium tetani in the soil of the United States. Health Lab Sci. 1978;15:74–80. 27. </ref> <ref>Sugiyama H. Clostridium botulinum neurotoxin. Microbiol Rev. 1980;44:419–448. 28. Dodds KL. Clostridium botulinum in the environment. In: Hauschild AHW </ref> <ref>Dodds KL, eds. Clostridium botulinum—Ecology and Control in Foods. New York, NY: Marcel Dekker, Inc; 1992: 21–51. 29. </ref> <ref>Popoff MR. Ecology of neurotoxigenic strains of clostridia. In: Montecucco C, ed. Current Topics in Microbiology: Clostridial Neurotoxins. The Molecular Pathogenesis of Tetanus and Botulism. Vol 195. Berlin, Germany: Springer-Verlag; 1995: 1–29. </ref>  . BTX is the protein responsible for causing botulism, a potentially fatal illness. Humans can be exposed to the neurotoxin through inhalation, ingestion, or surface wounds. There are seven forms of the protein, named A through G, that are structurally similar but create different immune responses <ref>  Hatheway cL. Clostridium botulinum and other clostridia that produce botulinum neurotoxins. in: Hauschild aHW, Dodds kL, eds. Clostridium botulinum—Ecology and Control in Foods. new york, ny: marcel Dekker, inc; 1992: 3–10 </ref>. The forms of BTX that most often cause botulism in humans are A, B, and E <ref> arnon SS, Schechter r, inglesby tV, et al. botulinum toxin as a biological weapon: medical and public health management. JAMA. 2001;285:1059–1070.</ref>.  

 

BTX is produced as a single chain protein in the bacterium, but becomes active when a protease cuts the protein into a heavy and light chain connected by a single disulfide bong. The heavy chain is approximately 100 kDa and the light chain is 50 kDa (for reviews about structure see references <ref>Sakaguchi G. 1983. Clostridium botulinum toxins. Pharmacol. Ther. 19:165–

Botulism is characterized by paralysis due to the interference of BTX with the release of acetylcholine at nerve synapses. The lethal doses for a human weighing 70 kg is 0.09-0.15 μg when administered intravenously or intramuscularly, 0.70 - 0.90 μg through inhalation, and 70 μg orally <ref>  Franz DR, Pitt LM, Clayton MA, Hanes MA, Rose KJ. Efficacy of prophylactic and therapeutic administration of antitoxin for inhalation botulism. In: DasGupta BR, ed. Botulinum and Tetanus Neurotoxins: Neurotransmission and Biomedical Aspects. New York, NY: Plenum Press; 1993:473-476. </ref> <ref>  Herrero BA, Ecklung AE, Streett CS, Ford DF, King JK. Experimental botulism in monkeys: a clinical pathological study. Exp Mol Pathol. 1967;6:84-95.</ref>.