Clostridium difficile bacteria, coloured scanning electron micrograph (SEM). These rodshaped bacteria cause pseudomembranous colitis, one of the most common hospitalacquired infections, and antibioticassociated diarrhoea. Infection can be fatal. Treatment is with antibiotic drugs, although this bacterium has become increasingly resistant to the use of antibiotics. Magnification: x1500 when printed at 10 centimetres high.
