To the Editor: The emergence of plasmid-mediated, and thus transfer-able, quinolone resistance determinants has been recently discovered (1) and shown to involve the pentapeptide repeat protein Qnr, which interacts with DNA gyrase and topoisomerase IV to prevent quinolone inhibition (2,3). Qnr determinants confer resistance to nalidixic acid and reduced susceptibility to fl uoroquinolones (3). ...
