Staphylococcus sp bacteria Coloured transmission electron micrograph TEM of a section through Staphylococcus sp bacteria These Grampositive spherical bacteria are normal inhabitants of the human ear canal nose and respiratory tract vagina and skin Many species are opportunistic pathogens causing diseases ranging from minor skin infections boils abscesses to potentially fatal systemic illnesses such as pneumonia and bacterial endocarditis Treatment is with antibiotics Magnification unknown