Prevalence in the United States of aac(6')-Ib-cr encoding a ciprofloxacin-modifying enzyme.
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.
Park
Chi Hye
CH
Division of Infectious Diseases, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114-2696, USA.
Robicsek
Ari
A
Jacoby
George A
GA
Sahm
Daniel
D
Hooper
David C
DC
D000123:Acetyltransferases / Q000235:genetics*; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D002939:Ciprofloxacin / Q000378:metabolism*; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004755:Enterobacteriaceae / Q000201:enzymology / Q000235:genetics; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects; D007711:Klebsiella pneumoniae / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D016017:Odds Ratio; D014481:United States / Q000453:epidemiology
D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin; D000123:Acetyltransferases; C443113:aminoglycoside 2'-N-acetyltransferase