False-colour transmission electron micrograph of the bacterium Vibrio cholerae (Gram-negative), cause of cholera in humans. Cholera is an acute infection of the small intestines causing severe vomiting & diarrhoea leading to dehydration. Dehydration may result in rapid death. The bacterium is a water borne pathogen, transmitted to humans through drinking water contaminated by human or animal faeces. Outbreaks of cholera are associated with poor sanitary conditions & often occur in epidemics. The bacterium moves by means of a flagellum (seen here). The yellow region (left) is the nucleic acid. Magnification: x8820 at 35mm size, x15,100 at 6x4.5cm size.