NorC, a new efflux pump regulated by MgrA of Staphylococcus aureus

NorC, a new efflux pump, like NorB, contributes to quinolone resistance that includes resistance to moxifloxacin and sparfloxacin in Staphylococcus aureus. norC expression, like that of norB and tet38, is negatively regulated by MgrA, and overexpression of both norC and norB contributes to the quinolone resistance phenotype of an mgrA mutant.