capitalized: a large genus (the type genus of the family Micrococcaceae) of nonmotile gram-positive spherical bacteria that occur in tetrads or irregular clusters and include nonpathogenic forms (as M. luteus) that are typically harmless saprophytes on human skin but may cause opportunistic skin infections in immunocompromised individuals
pluralmi·cro·coc·ci\-ˈkäk-ˌ(s)ī\: a small spherical bacterium; especially: any bacterium of the genus Micrococcus
Any of the spherical bacteria that make up the genus Micrococcus. Widespread in nature, these gram-positive (seegram stain) cocci (seecoccus) are usually not considered to cause disease. They are normal inhabitants of the human body and may even be essential in keeping the balance among the various microorganisms found on the skin. Some species are found in the dust of the air, in soil, in marine waters, and on the skin of vertebrates. Certain species are found in milk and can result in spoilage.