Cholera is an acute enteric infection caused by the bacterium Vibrio cholerae. It is characterised by copious, watery diarrhoea that can lead to severe dehydration and death if untreated. Cholera remains a serious public health problem in many developing countries, particularly those with inadequate sanitation and poor access to safe water. The disease is typically spread through contaminated food or water, and person-to-person contact. Treatment of cholera is primarily with rehydration therapy – fluids and electrolytes to replace those lost through diarrhoea – which must be given promptly to prevent death.
Vibrio cholerae is a Gram-negative, comma-shaped bacterium that is mobile due to the presence of a single polar flagellum. It is a facultative anaerobe that can grow in the absence of oxygen using fermentation or aerobic respiration. V. cholerae has two circular chromosomes (2,961,149 base pairs each) encoding 3,885 genes; however, only one chromosome (the smaller one) is needed for survival under most conditions (i.e., it encodes essential genes). The larger chromosome has been acquired over evolutionary time and contains regions of DNA that are not essential for survival but may provide advantages under certain conditions such as exposure to antibiotics