Complete Deletion of the ramR Gene in an In Vitro -Selected Mutant of Klebsiella pneumoniae Overexpressing the AcrAB Efflux Pump

Abstract

In Klebsiella pneumoniae, overexpression of nonspecific efflux pumps causes low-level cross-resistance to β-lactams (mainly cefoxitin) and to antibiotics belonging to other families, such as quinolones, chloramphenicol, and tetracycline ([1][1], [2][2]). Among these efflux systems, the pump AcrAB