“Targeted” prophylaxis: Impact of rectal swab culture-directed prophylaxis on infectious complications after transrectal ultrasound-guided prostate biopsy

PURPOSE To assess the prevalence of fluoroquinolone resistance among patients undergoing transrectal ultrasound (TRUS)-guided prostate biopsy and the impact of rectal swab culture-directed antibiotic prophylaxis on postbiopsy infectious complications. MATERIALS AND METHODS We prospectively analyzed all patients undergoing TRUS-guided prostate biopsy from April 2013 to February 2015. Antibiotic prophylaxis was tailored to the results of rectal swab cultures. If the organism was fluoroquinolone-sensitive, oral ciprofloxacin 500 mg with tinidazole 600 mg was prescribed. If the organism was fluoroquinolone-resistant, then a culture-directed antibiotic was prescribed. In both cases the antibiotic was continued for 3 days. All patients were followed for 14 days after biopsy to record infectious complications. RESULTS A total of 247 patients were included, and Escherichia coli was isolated on rectal swab cultures in 99.5% of the patients. Of these, 41.7% harbored fluoroquinolone-resistant E. coli. Piperacillin/tazobactam was the most common culture-directed antibiotic prescribed (59.3%), with amoxicillin/clavulanic being the second most common (25.5%) for the fluoroquinolone-resistant group. Only 2 patients (0.9%) developed postbiopsy fever and none had sepsis. CONCLUSIONS Colonization of rectal flora with fluoroquinolone-resistant E. coli was seen in 40% of men undergoing prostate biopsy. Targeted prophylaxis, which uses the results of prebiopsy rectal swab culture to direct antibiotic prophylaxis, results in low rates of postbiopsy infections.