Scanning electron micrograph (SEM), tinted yellow, of the comma-shaped bacterium, Vibrio cholerae, the cause of cholera. The bacterium moves by means of a single terminal flagellum (seen here). The spread of cholera is associated with poor sanitation and water supplies contaminated by faeces from a patient. The bacteria lodge primarily in the small intestines causing inflammation, vomiting, diarrhoea and ultimately dehydration. Magnification: X 2,850 at 35mm size. Original is BW print B220/074.