RESUMO
OBJECTIVE: To study the trends of antimicrobial resistance of Escherichia coli in Thailand during 2000 and 2005. MATERIAL AND METHOD: All isolates of E. coli from 28 hospitals across Thailand from 2000 to 2005 were tested for their susceptibility to aminoglycosides, beta-lactams, fluoroquinolones, and trimethoprim-sulfamethoxazole by the disk diffusion method (Kirby Bauer). The relevant data were collected and analyzed by the WHONET software program supported by the World Health Organization. RESULTS: The rate of resistance to ampicillin, ceftriaxone, ceftazidime gentamicin, and ciprofloxacin increased from 79.3% to 85.3%, 12.7% to 28.5%, 10.7% to 15.2%, 25% to 32.9%, and 45.1% to 51% during the 6-year period from 2000 to 2005 among isolates from catheterized urine, respectively. The rate of resistance to gentamicin and ceftriaxone increased from 23.2% to 28.9% and 6.8% to 24.2%, from 2000 to 2005 respectively among isolates in non-intensive care units (non-ICUs). The rate of resistance to gentamicin increased from 18% to 26.1%, and 24.2% to 29.6% among isolates in out-patient department (OPD) and non-OPD, respectively. The rate of resistance to ceftriaxone increased from 2.5% to 15.4%, and 7.9% to 25.9% among isolates in OPD and non-OPD, respectively. The rate of resistance to gentamicin and ceftriaxone increased from 23.2% to 28.9%, and 6.8% to 24.2% among isolates in non-ICU, respectively. The rate of resistance to trimethoprim-sulfamethoxazole decreased from 71.2% to 62.6% among isolates in non-ICUs. Isolates from catheterized urine were significantly associated with imipenem resistance (p > 0.05). CONCLUSION: The present study shows a significant correlation between ciprofloxacin resistance and fluoroquinolone use, and indicates that prior fluoroquinolone use seems to be the most important risk factor for ciprofloxacin-resistant E. coli bacteremia. Isolates from catheterized urine were significantly associated with resistance to imipenem, and the ICU hospitalization and OPD attention during the previous year were significantly associated with ofloxacin resistant E. coli.