Clostridium difficile bacteria, coloured transmission electron micrograph (TEM). These Grampositive rodshaped bacteria can cause pseudomembranous colitis (infection of the colon), one of the most common hospitalacquired infections, and antibioticassociated diarrhoea. These disorders are often due to the use of antibiotics, which kill off normal gut flora and can lead to an overgrowth of C. difficile. Infection can be fatal. Magnification: x53,500 when printed at 10 centimetres tall.
