コレラ菌は、ビブリオ属に属するグラム陰性のコンマ型をした桿菌の一種。
しばしば誤解されるが、コレラ菌のすべてがコレラの原因ではなく、200種類以上の血清型に分類された中の「コレラ毒素を産生するO1型もしくはO139型のコレラ菌」が、ヒトに感染してコレラの原因になる。
O1型は古典型とエルトール型に分類される。
また、これ以外のコレラ菌もヒトに感染して食中毒の原因になる。
Vibrio cholerae is a Gram-negative, comma-shaped bacterium. The bacterium's natural habitat is brackish or saltwater. Some strains of Vibrio cholerae cause the disease cholera. Vibrio cholerae is a facultative anaerobe and has a flagellum at one cell pole as well as pili. Vibrio cholerae can undergo respiratory and fermentative metabolism. When ingested, Vibrio cholerae can cause diarrhoea and vomiting in a host within several hours to 2–3 days of ingestion. Vibrio cholerae was first isolated as the cause of cholera by Italian anatomist Filippo Pacini in 1854, but his discovery was not widely known until Robert Koch, working independently 30 years later, publicized the knowledge and the means of fighting the disease.