MOLECULAR EPIDEMIOLOGIC ANALYSIS OF QUINOLONE-RESISTANT ESCHERICHIA-COLI CAUSING BACTEREMIA IN NEUTROPENIC PATIENTS WITH LEUKEMIA IN KOREA

We analyzed an outbreak of Escherichia coli bacteremia in eight patien ts with leukemia in a hematology-oncology unit from July to September 1994, The antibiograms and genotypic patterns of the isolates were dif ferent, thus suggesting that the outbreak did not originate from a sin gle clone. However, all the isolates were resistant to quinolones, whi ch led us to examine the microbiological records from 1992 to 1994, Th e incidence of quinolone-resistant E, coli bacteremia in the hematolog y-oncology unit ranged from 81.8% to 94.6% during this period, We then analyzed 36 more isolates recovered from late 1994 to 1995. Field inv ersion gel electrophoresis patterns of these isolates were also differ ent. Analysis of the quinolone resistance determining region in gyrA r evealed that all the isolates had a double mutation in gyrA. In conclu sion, quinolone-resistant E. coli could be an emerging threat to neutr openic patients with leukemia who receive a quinolone prophylactically , and attention must be paid to this trend of resistance.