Antimicrobial Resistance of Escherichia coli Isolated from urine in Thailand from 2000 to 2005
Pitimon Polwichai MSc*, Surang Dejsirilert MSc*, Sirikul Panpetch BSc*, Pathom Sawanpanyalert MD, DrPh*, Nalinee Aswapokee MD**, Piroon Mootsikapun MD***
Affiliation : * National Institute of Health, Department of Medical Sciences, Nonthaburi, Thailand ** Unit of Infectious Diseases, Faculty of Internal Medicine, Siriraj University Hospital, Mahidol University, Bangkok, Thailand *** Infectious Disease Unit, Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
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.
Keywords : Anti-bacterial agents, Ciprofloxacin, Drug resistance, Microbial, Escherichia coli, Fluoroquinolones, Microbial sensitivity tests, Thailand, Urinary tract infections
