Complex sentence: MRSA is any strain of "Staphylococcus aureus" that has developed, through horizontal gene transfer and natural selection, multi- resistance to beta-lactam antibiotics, which include the penicillins (methicillin, dicloxacillin, nafcillin, oxacillin, etc.) and the cephalosporins.
Split into simpler sentences: MRSA is any strain of "Staphylococcus aureus" that has developed, through horizontal gene transfer and natural selection, multi- resistance to beta-lactam antibiotics. This includes the penicillins (methicillin, dicloxacillin, nafcillin, oxacillin, etc.) and the cephalosporins.