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''Clostridium botulinum'' is a Gram-positive, rod-shaped, anaerobic, spore-forming, motile bacterium with the ability to produce the neurotoxin botulinum. The botulinum toxin can cause a severe flaccid paralytic disease in humans and other animals〔 and is the most potent toxin known to humankind, natural or synthetic, with a lethal dose of 1.3–2.1ng/kg in humans.〔(2010). Chapter 29. Clostridium, Peptostreptococcus, Bacteroides, and Other Anaerobes. In Ryan K.J., Ray C (Eds), ''Sherris Medical Microbiology'', 5th ed. ISBN 978-0071604024〕 ''C. botulinum'' is a diverse group of pathogenic bacteria initially grouped together by their ability to produce botulinum toxin and now known as four distinct groups, ''C. botulinum'' groups I-IV. ''C. botulinum'' groups I-IV, as well as some strains of ''Clostridium butyricum'' and ''Clostridium baratii'', are the bacteria responsible for producing botulinum toxin.〔 ''C. botulinum'' is responsible for foodborne botulism (ingestion of preformed toxin), infant botulism (intestinal infection with toxin-forming ''C. botulinum''), and wound botulism (infection of a wound with ''C. botulinum''). ''C. botulinum'' produces heat-resistant endospores that are commonly found in soil and are able to survive under adverse conditions.〔 ==Microbiology== ''C. botulinum ''is a Gram-positive, rod-shaped, spore-forming bacterium. It is an obligate anaerobe, meaning that oxygen is poisonous to the cells. However, ''C. botulinum'' tolerates traces of oxygen due to the enzyme superoxide dismutase, which is an important antioxidant defense in nearly all cells exposed to oxygen. ''C. botulinum'' is only able to produce the neurotoxin during sporulation, which can only happen in an anaerobic environment. Other bacterial species produce spores in an unfavorable growth environment to preserve the organism's viability and permit survival in a dormant state until the spores are exposed to favorable conditions. ''C. botulinum ''is divided in to four distinct phenotypic groups (I-IV) and is also classified into seven serotypes (A-G) based on the antigenicity of the botulinum toxin produced. Recently, an eighth serotype (H) has been described. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Clostridium botulinum」の詳細全文を読む スポンサード リンク
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