Risk Factor Analysis Among Trimethoprim-Sulfamethoxazole Resistant Escherichia coli Isolates

Trimethoprim-sulfamethoxazole (tmp-smx) can be used for treatment of several infections including respiratory, renal, and gastrointestinal tract infections, skin and wound infections, septicaemia, and other infections caused by sensitive organisms. the aim of this study was to evaluate the risk factors for acquisition of tmp-smx-resistant escherichia coli strains among hospitalized patients in a university hospital of sanandaj, iran. it was a case-control study on a patient, carrying a tmp-smx-resistant e. coli strain. the control patient carried a tmp-smx-sensitive e. coli strain. tmp-smx resistance was determined using disk diffusion methods. of 343 isolates, 197 (57.43%) were tmp-smx-resistant. using ventilator and catheter were risky for acquisition of tmp-smx-resistant isolate (odds ratio (or) = 3.037, 95% ci = 1.60-5.75, p < 0.000; or = 2.93, 95% ci = 1.15-7.43, p < 0.013, respectively). there was significant correlation between days of stay in ward and tmp-smx resistance (p < 0.003). the main risk factors associated with tmp-smx resistance were use of ventilator and catheter and days of stay in ward. there is need for more studies to evaluate the role of this factor to control the spread of drug resistance.