The aim of this study was to evaluate the dependence of Escherichia coli resistance to fluoroquinolones on their use in the outpatients and inpatients in the Hradec Kralove region of the Czech Republic. Data on inpatient fluoroquinolones use were obtained from the database of the Charles University Teaching Hospital Pharmacy and expressed as defined daily dose per 100 beds - days (DBD). Data on outpatient prescriptions were obtained from the database of the General Health Insurance Company and expressed in defined daily doses per 1000 clients per day (DID). Escherichia coli strains were isolated from samples of urine of both community and hospitalized patients suffering from acute bacterial urinary tract infection, examined using aerobic cultivation, and determined by standard biochemical procedures. The utilization of fluoroquinolones in inpatients has significantly (p < 0.01) increased from 2.73 DBD in 2001 to 4.89 DBD in 2006. In outpatients, fluoroquinolone utilization has also increased significantly from 0.29 DID to 1.15 DID (p < 0.01). In the same period, 11,856 Escherichia coli strains were isolated from inpatients and outpatients with urinary tract infection and tested for the susceptibility to fluoroquinolones. Resistance increased significantly (p < 0.01), both in the hospital (from 2% to 10%) and in the community (from 1% to 11%). The development of Escherichia coli resistance to fluoroquinolones correlates significantly with their utilization both in hospital (r = 0.996, p = 0.005) and in the community (r = 0.878, p = 0.029). Results of this study shows the impact of fluoroquinolone utilization on Escherichia coli resistance, and support the need of controlled use of these effective antibiotics.

The Uppsala Monitoring Centre WHO Collaborating Centre for International Drug Monitoring Uppsala Sweden