Mecanismos de resistencia a quinolonas mediada por plásmidos

Quinolone resistance is caused mainly by chromosomal mutations in gram negative bacteria. In 1998, plasmidmediated resistance to quinolones in clinical isolates was first reported in a Klebsiella pneumoniae strain. Locus qnr (quinolone resistance) was responsible of the quinolone resistance in this plasmid. qnr codes a protein whose function is protect both DNA-girase and topoisomerase IV from these antimicrobials. Moreover, qnr is located in an integron-like structure upstream of qacEΔ1 y sull. A review of the information obtained in the last years about this mechanism of resistance was performed.