False-colour transmission electron micrograph (TEM) of bacteria Staphylococcus aureus, showing a complete bacterium (centre) & the plasma membrane remains (top right) of another bacterium burst by lysis, due to effects of antibiotics. Lysis occurs through the destruction of the outer plasma membrane (appears blue around complete bacterium), & the release of intracellular contents into the surrounding medium. S. aureus (a species of spherical, non-motile, Gram-positive bacteria) is responsible for pus containing infections such as boils and abscesses. S. aureus also secretes an exotoxin causing a type of acute gastro-enteritis. Magnification: X 17,500 at 35mm size.