Pseudomonas aeruginosa bacteria, coloured scanning electron micrograph (SEM). These Gramnegative rodshaped bacteria are found in soil and water, and as normal flora in the human intestine. However, they can cause serious wound, lung, skin and urinary tract infections. These types of infections are most common in hospitals. Treatment is with antibiotics. Magnification: x4590 when printed at 10 centimetres wide.
