Urinary tract infections (UTIs) account for about 30%–40% of all hospital associated infections and are important since they increase mortality, morbidity, duration of hospital stay and health costs ^1–3. The most important risk factor for developing a UTI is urinary catheterization. It is estimated that 15%–25% of all the patients hospitalized in health centers undergo urinary catheterization at least once during their hospital stay and it is reported that the frequency of urinary catheterization has increased in the past 20 years. Patients admitted to intensive care units (ICU) are the most appropriate candidates for UTIs due to their more frequent necessity of urinary catheterization and longer duration of catheter use ^1,3,4. ]Bacteriuria or candiduria is almost inevitable in nearly half of the patients who require an indwelling urinary catheter for more than 5 days ^5,6. Asymptomatic bacteriuria constitutes a major pool of the antibiotic–resistant strains of pathogens in any hospital, with critical care units (CCUs) accounting for the majority of them ^7,8. Catheter associated urinary tract infection (CAUTI)  is also a major cause of hospital–acquired bacteremia ⁶ and even asymptomatic bacteriuria may be associated with enhanced in–hospital mortality rates ⁹.