Risk Factors for Fluoroquinolone Resistance in Nosocomial Escherichia coli and Klebsiella pneumoniae Infections

Abstract
THE INTRODUCTION of the fluorinated quinolones in the mid-1980s was heralded not only because of their high potency and broad spectrum of activity, but also because the potential for development of resistance to these agents was predicted to be very low, particularly among the Enterobacteriaceae.1 In the 5 years after their initial introduction, there were few reports of resistance despite widespread use of these agents. Early descriptions of fluoroquinolone (FQ) resistance were largely limited to Staphylococcus aureus and Pseudomonas aeruginosa, organisms with intrinsically marginal susceptibility to these agents.2