Background Asymptomatic bacteriuria (ABU) refers to the presence of germs in the urinary tract without clinical symptoms. ABU is frequent in hospitalised patients.

Purpose To determine the prevalence of ABU in a clinical emergency hospital in patients who received unjustified antibiotic treatment because they did not show symptoms of urinary tract infections (UTIs).

Material and methods We evaluated 76 patients admitted to our hospital between March and August 2015, with average age of 71.4 (±8.2) years, of whom 59 women (77.63%) were women. We excluded patients >85 years old, patients undergoing invasive urological and surgical procedures and immunocompromised patients. Urine samples were collected within 24 h of admission by the midstream method and subjected to bacteriological diagnosis using the calibrated loop method. Identification of isolated microorganisms and antimicrobial sensitivity testing were carried out by an automated method (Phoenix analyser, BD Diagnostics, USA).

Results 54 patients (71.05%) were admitted through the emergency room, of whom 3 (3.94%) already had a urinary catheter at the time of admission. In 34 patients (44.73%) the urine sample was contaminated. These samples were collected again and were negative. ABU was present in 26 (34.21%) patients with no UTI symptoms, but with positive urine culture for E coli Proteus Pseudomonas Klebsiella and Serratia. Of these, 14 patients (53.84%) received antimicrobials. 5 of 14 patients (35.71%) had significant bacteriuria (presence of >100 000 colony forming units/mL urine) and received antimicrobial therapy, and the remaining 9 patients (64.29%) received antibiotics totally unjustified. Many isolated strains had multiple resistance to antibiotics.

Conclusion The study demonstrates the importance of bacteriological testing of urine in inpatients for the purpose of screening for silent ITU and prevention of the unjustified empirical treatment of ABU. The hospital clinical pharmacist must actively collaborate with prescribing clinicians to avoid incorrect treatment and to decrease antibiotic consumption.

No conflict of interest.