Clinical epidemiology of ciprofloxacin resistance and its relationship to broad-spectrum cephalosporin resistance in bloodstream infections caused by Enterobacter species.
OBJECTIVE
To evaluate the clinical features of ciprofloxacin-resistant Enterobacter bacteremia and to examine the risk factors for ciprofloxacin resistance in Enterobacter species isolates causing bacteremia.


METHODS
A case-control study.


METHODS
A 1,500-bed, tertiary-care university hospital and referral center.


METHODS
All patients older than 16 years with Enterobacter species isolated from blood were enrolled. The medical records of 183 patients with clinically significant Enterobacter bacteremia from January 1998 to December 2002 were identified. We compared patients with bacteremia caused by ciprofloxacin-susceptible isolates with patients with bacteremia caused by ciprofloxacin-resistant isolates.


RESULTS
Twenty-three (12.6%) of the patients had bacteremia caused by isolates resistant to ciprofloxacin. There were no significant differences in age, gender, underlying diseases, primary site of infection, or Acute Physiology and Chronic Health Evaluation II score between the ciprofloxacin-resistant and the ciprofloxacin-susceptible groups. Broad-spectrum cephalosporin resistance, defined as resistance to cefotaxime or ceftazidime in vitro, was detected in 21 (91.3%) of 23 ciprofloxacin-resistant isolates compared with 65 (40.6%) of 160 ciprofloxacin-susceptible isolates (P < .001). Multivariate analysis revealed that independent risk factors for ciprofloxacin resistance were the prior receipt of fluoroquinolones (P < .001) and broad-spectrum cephalosporin resistance (P < .001).


CONCLUSIONS
In Enterobacter species isolates causing bacteremia, ciprofloxacin resistance was closely associated with the prior receipt of fluoroquinolones and broad-spectrum cephalosporin resistance. The close relationship between ciprofloxacin resistance and broad-spectrum cephalosporin resistance is particularly troublesome because it severely restricts the therapeutic options for Enterobacter species infection.
Kang
Cheol-In
CI
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
Kim
Sung-Han
SH
Park
Wan Beom
WB
Lee
Ki-Deok
KD
Kim
Hong-Bin
HB
Kim
Eui-Chong
EC
Oh
Myoung-don
MD
Choe
Kang-Won
KW
D000293:Adolescent; D000328:Adult; D000368:Aged; D000890:Anti-Infective Agents / Q000493:pharmacokinetics*; D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology; D016022:Case-Control Studies; D002511:Cephalosporins / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D004754:Enterobacter / Q000187:drug effects*; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006785:Hospitals, University / Q000706:statistics & numerical data; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
D000890:Anti-Infective Agents; D002511:Cephalosporins; D002939:Ciprofloxacin