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

摘要

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.