Cholera is caused by the bacterium Vibrio cholerae belonging to the  genus Vibrio of family Vibrionaceae .
The spread of cholera occurs through ingestion of contaminated food or water. It is an infectious disease leading to rapid dehydration and  severe diarrhoea as a result of toxin produced by the bacteria in the small intestine. The toxin released in intestine cause body to secrete more water causing diarrhoea with loss of body fluids and salts.

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Vibrio cholerae , the causative organism of the disease cholera and the producer of several different toxins, belongs to the family Vibrionaceae , the genus Vibrio and the species V. cholerae .

The basis of its further subclassification or sub-typing into serogroups, serotypes, biotypes, and phage types has been elucidated. The molecular subtyping of V. cholerae strains in accordance with (i) plasmid profile analysis, (ii) restriction fragment length polymorphism (RFLP) of ctx and rRNA genes including their flanking regions, (iii) zymovar analysis of the enzymes produced, (iv) pulsed field gel electrophoresis of isolated DNA fragments, etc., has produced results of great epidemiological significance.