Increase in Resistance of Methicillin-Resistant <b> <i>Staphylococcus aureus</i> to β-Lactams Caused by Mutations Conferring Resistance to Benzalkonium Chloride, a Disinfectant Widely Used in Hospitals </b>

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) has been found worldwide and is one of the major nosocomial agents. When MRSA strains were first discovered in hospitals, resistance of MRSA to low concentrations of β-lactams was evident, but increasing resistance to high concentrations of β-