Bacteremia due to quinolone-resistant Escherichia coli in a teaching hospital in South Korea

Quinolone-resistant Escherichia coli (QREC) strains are being isolated with increasing frequency. From 1993 to 1998, 40 cases of QREC bacteremia were observed in a teaching hospital; 25 episodes (63.5%) were community-acquire d. The incidence of QREC bacteremia increased steadily, from 6.7% to 24.6% during 5 years, and correlated with the significantly increased use of fluo roquinolones (P = .003, r = 0.98). When the 40 QREC bacteremic patients wer e compared with 80 patients with bacteremia due to quinolone-susceptible E. coli, prior fluoroquinolone use was the only independent risk factor for Q REC bacteremia (P = .001). A high APACHE II score was the only independent risk factor for death. The rate of multidrug resistance of QREC was much hi gher (60%) than that of quinolone-susceptible isolates (13.8%). Pulsed-fiel d gel electrophoresis patterns of these isolates were diverse. Therefore, t he isolates revealed little evidence of clonal spread and may have emerged in direct response to the selective pressure exerted by prior fluoroquinolo ne use.