although psms are present in every "staphylococcal" species, there is still diversity. "staphylococcus aureus" encodes eight different psms, psmα 1-4, psmβ 1-2, psmγ (also known as δ-toxin in "s. aureus"), and psm-mec. while "staphylococcus epidermidis" encodes one psmα, psmβ 1-2, psmγ, and psm-mec. in addition "s. epidermidis" encodes two unique psms, psmδ and psmε.