Introduction: Prostate cancer is a common male malignancy, and transrectal ultrasound-guided biopsy (TRUSBx) is the standard diagnostic method despite infection risks. The value of routine urine culture in asymptomatic patients remains unclear. This study aimed to evaluate pre-biopsy urine cultures in asymptomatic TRUSBx patients at a tertiary hospital, analyzing bacterial growth, isolated microorganisms, and antibiotic resistance.
Materials and Methods: This retrospective study included asymptomatic male patients aged 40–80 years who underwent TRUSBx between June 2019 and December 2024 and had a pre-biopsy urine culture. Patients with urinary catheters, recent urogenital or rectal surgery, or recent antibiotic use or hospitalization in the three months were excluded. A positive urine culture was defined as bacterial growth ≥10⁵ CFU/ml. Data were retrieved from hospital records.
Results: A total of 1548 male patients with pre-biopsy urine cultures were included in the study. The mean age was 65.2 years, and the mean PSA level was 10.2 ng/mL. Bacterial growth was detected in 66 patients (4.3%). Of these, 44 isolates (67%) were gram-negative and 22 (33%) were gram-positive. Escherichia coli was the most common gram-negative organism, while Enterococcus faecalis was the most frequently isolated gram-positive species. Among E. coli isolates, the highest resistance rate was observed against amoxicillin-clavulanate (65%), whereas resistance to fluoroquinolones was 17.4%.
Discussion and Conclusion: Bacterial growth was observed in <5% of asymptomatic males undergoing TRUSBx, with E. coli as the most common pathogen. Fluoroquinolone resistance was near the threshold, highlighting the need for local antimicrobial resistance data in prophylactic antibiotic planning.