False-colour transmission electron micrograph (TEM) of Staphylococcus epidermidis, a species of spherical, gram positive, non-motile bacteria. 2 bacteria are seen dividing by binary fission. S. epidermidis is generally non-pathogenic in man, occuring on the skin and on many mucous membranes. However, the bacterium's ability to colonize plastic has resulted in infections around catheters & surgical implants (cerebro-spinal fluid shunts & heart valves, for example). Such infections often fail to respond to antibiotics, and the implants may have to be removed. Magnification: X 12,000 at 35mm size, x24,000 at 6x7cm size.