Rectal and urethral flora in patients undergoing transrectal ultrasound guided prostate biopsy: clinical implications.

Patients in intervention group are subjected to cultures of rectal swab and urethral swab of expressed prostatic secretions. At the time of the first visit samples are collected by a single urologist. At first, rectal swab sample is retrieved, followed by digital rectal examination and prostatic massage. Finally, urethral swab is used to collect expressed prostatic secretions. The sample is collected after retraction of prepuce and cleaning of urethral meatus with normal saline. A swab is then inserted approximately 2cm into urethra. Samples are sent to microbiology department for cultures. A predetermined antibiotic panel was used for rectal cultures with the following anibiotics: amoxycillin, ampicillin, amoxycillin/clavulanic acid, cefaclor, ceftazidime, amikacin, imipenem, norfloxacin, levofloxacin, ciprofloxacin, tigecycline, colistin and gentamycin. The antibiotic panel used for urethral cultures varied according to isolated bacteria. Based on culture results, patients are contacted and instructed to receive targeted antibiotic prophylaxis for a total of 5 days, initiated 1 day prior to prostate biopsy. Antibiotic selection was guided by known allergies, antimicrobial sensitivity, the provided minimum inhibitory concentration (MIC) and in compliance with the local antibiotic protocol of the department, which also determined the dose of the selected antibiotics. No complimentary instructions are given regarding pre-biopsy enema. Patients are subjected to twelve core TRUS-PBx with an 18G biopsy needle by a urologist. The approximate duration of the procedure is 10 to 15 minutes. The occurrence of infectious complications is investigated and verified at the time of biopsy results announcement by interviewing patients. At the same time, patients' adherence to given instructions is investigated by interviewing the patients and by drug tablet return. The allocation to the groups was carried out during the first visit to Urology outpatient clinic. Those not willing to give samples for culture and those who were referred by office urologists, directly for TRUS-Bx, were assigned to empiric antibiotic prophylaxis group and the rest of the patients were assigned to targeted antibiotic prophylaxis group.