The 5′UTR effect of norA gene over the efflux was studied in S. epidermidis. Isolates had a high efflux activity (HEA) phenotypic for ethidium bromide (EtBr). Isolates with HEA had the 5′UTR 95ΔG mutation and high levels of norA expression. The 95ΔG mutation produces changes in the Shine-Dalgarno region. The 5′UTR 95ΔG mutation of norA gene is involved in the EtBr efflux.