Transient loss of high-level mupirocin resistance in Staphylococcus aureus due to MupA polymorphism

Abstract

Spontaneous loss of MupA-mediated high-level mupirocin resistance was observed in Staphylococcus aureus, although the isolate gave a PCR-positive test result for mupA. Sequencing of the mupA gene identified a single base-pair deletion that resulted in a frameshift mutation and loss of functional protein. Reversion to the wild-type allele and restoration of high-level resistance occurred with high frequency (>10-6), indicating the transient nature of MupA polymorphism. Copyright © 2007, American Society for Microbiology. All Rights Reserved.