Specificity of 4'''-Acetylation by an Aminoglycoside-Modifying Enzyme in Arbekacin-Resistant Strains of Methicillin-Resistant Staphylococcus aureus

Abstract

Four arbekacin (ABK)-resistant clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) were studied regarding their mechanism of aminoglycoside-resistance. Metabolites of amikacin (AMK) and gentamicin(GM) were obtained by reaction with excess amounts of crude enzyme preparation extracted from the ABK-resistant MRSA strains. Then the metabolites were then isolated and analyzed by means of ¹H, ¹³C-nuclear magnetic resonance. The AMK-modification was 4'''-N-acetylation. However, the site of GM-acetylation may be 6'-N-position by these strains.