Prevalence in the United States of <i>aac(6</i> ′ <i>)</i> - <i>Ib</i> - <i>cr</i> Encoding a Ciprofloxacin-Modifying Enzyme
Chi Hye Park(Massachusetts General Hospital), Ari Robicsek(NorthShore University HealthSystem), George A. Jacoby(Lahey Hospital and Medical Center), Daniel F. Sahm, David C. Hooper(Massachusetts General Hospital)
Cited by 748Open Access
Abstract
Among 313 Enterobacteriaceae from the United States with a ciprofloxacin MIC of >/=0.25 microg/ml and reduced susceptibility to ceftazidime, aac(6')-Ib was present in 50.5% of isolates, and of these, 28% carried the cr variant responsible for low-level ciprofloxacin resistance. aac(6')-Ib-cr was geographically widespread, stable over time, most common in Escherichia coli, equally prevalent in ciprofloxacin-susceptible and -resistant strains, and not associated with qnr genes.