The repeated use of drugs to fight MRSA infections increases the likelihood that MRSA will also develop resistance to these drugs as well. As stated previously, some Staphylococcus aureus strains are becoming resistant to vancomycin through vanA. Resistance to vancomycin as well as the beta-lactam antibiotics (penicillin, methicillin…) would make fighting Staphylococcus aureus infections even more difficult than fighting MRSA infections.