Burkholderia pseudomallei bacteria dividing, coloured scanning electron micrograph (SEM). These motile bacteria are the cause of melioidosis, a tropical disease spread through contaminated water and soil. The bacteria can infect the skin, causing inflammation and muscle aches, or the lungs, causing chest pain, cough and in some cases pneumonia. The disease may stay localised or spread through the bloodstream infecting the organs, joints and eyes. Treatment is with antibiotics. Magnification: x30,000 when printed 10 centimetres wide.