Staphylococcus aureus is a very common bacteria often found growing harmlessly on the skin. Although originally responsive to penicillin, strains soon emerged that were resistant to the antibiotic. When a derivative of penicillin called methicillin was developed to combat these strains, Methicillin-resistant Staphylococcus aureus (MRSA) materialized. And the antibiotic resistance of MRSA-strains continues to improve: some strains of this “superbug” are now resistant to virtually all known treatm