Staphylococcus

Staphylococcus is a genus of Gram-positive bacteria in the family Staphylococcaceae in the order Bacillales. Under the microscope, they appear spherical (cocci), and form in grape-like clusters. Staphylococcus species are facultative anaerobic organisms (capable of growth both aerobically and anaerobically). Staphylococcus includes at least 40 species, in which nine have two subspecies , one has three subspecies, and one has four subspecies. Most are harmless and reside normally on the skin and mucous membranes of humans and other organisms. Staphylococcus has been found to be a nectar-inhabiting microbe. They are a small component of soil microbial flora. Members of the genus Staphylococcus frequently colonize the skin and upper respiratory tracts of mammals and birds. Some species specificity has been observed in host range, such that the Staphylococcus species observed on some animals appear more rarely on more distantly related host species.