Quinolone-resistant E. coli Bacteremia: Clinical & Microbiologic Characteristics

Cheong, Hee Jin; Yoo, Chul Woong; Choi, Jong Il; Park, Cheong Won; Kim, Woo Joo; Kim, Min Ja; Park, Seung Chul

Abstract

From the prudent use of quinolone in clinical practice, quinolone-resistant E. coli strains are being isolated with increasing frequency in the community as well as in the hospital. To analyze the risk factors, clinical features and prognosis of QREC, we reviewed the microbiologic records of E. coli bacteremia patients, estimated the quinolone consumption and performed the PFGE to compare genetic diversity. From 1994 to 1998, 40 episodes of QREC bacteremia were observed, 15 cases (37.5%) were hospital acquired. Overall, there is significant correlation between the increased incidence of QREC bacteremia and the upward trend in quinolone use in the hospital as out-and in-patients medication (P=0.003, r=0.98). When we compare the 40 case patients with 80 simultaneous control patients who had quinolone-susceptible E. coli bacteremia, the case patients more frequently had chronic underlying illness, prior use of quinolones and other antibiotics. Quinolone resistance was not significantly associated with higher mortality. A logistic regression analysis identified prior quinolone (P=0.001) use and prior use of other antibiotics (P=0.04) as the only independent risk factors for QREC bacteremia. 10-or 8-different PFGE patterns were observed in QREC isolates from community and hospital. They revealed little evidence of clonal spread, and may have emerged in direct response to the selective pressure exerted by antibiotic use.