Cloning and Characterization of a Novel Trimethoprim-Resistant Dihydrofolate Reductase from a Nosocomial Isolate of <i>Staphylococcus aureus</i> CM.S2 (IMCJ1454)

Abstract

A novel gene, dfrG, encoding a trimethoprim (TMP)-resistant dihydrofolate reductase (DHFR, designated S3DHFR) was cloned from a clinical isolate of methicillin-resistant Staphylococcus aureus. Escherichia coli expressing dfrG was highly resistant to TMP. Recombinant S3DHFR exhibited DHFR activity that was not inhibited by TMP.