Legionella pneumophila bacteria

Under a magnification of 43,700X, this transmission electron micrograph (TEM) created from a whole preparation of Legionella pneumophila bacteria that had been negatively stained using uranyl acetate, and grown on bacteriologic medium, reveals L. pneumophila organisms reproducing, undergoing the process of cell division, as well as delineating the bacterium's outer envelope. Legionnaires' disease can have symptoms like many other forms of pneumonia, so it can be hard to diagnose. Image courtesy CDC/Dr. Francis Chandler, 1978. (Photo by Smith Collection/Gado/Getty Images).