NorK, a novel norfloxacin efflux pump in Staphylococcus aureus

Abstract A novel efflux pump similar to Nor efflux pumps and designated as NorK was identified in Staphylococcus aureus . It contributes to norfloxacin resistance and presents a high level of expression in different strains. Its expression is not regulated by MgrA, unlike other genes of the nor gene family, suggesting that NorK could be important in the absence of expression of other nor genes.