Royalty free and rights managed images of Staphylococcus bacteria. Staphylococcus bacteria are an example of cocci (round bacteria). There are over 40 species of Staphylococcus bacteria, some of which cause disease in humans though most are harmless. Many of the species are found on the skin and mucous membranes. Staphylococcus species are Gram-positive bacteria. Images include bacterial cultures in petri dishes, illustrations and diagrams, as well as light micrographs, scanning electron micrographs (SEMs), and transmission electron micrographs (TEMs).