The clinical efficacy of rectal swab culture before transrectal ultrasound guided prostate biopsy for preventing infective complications and characteristics of quinolone resistant Escherichia Coli isolated from the rectal swab

Purpose: Transrectal ultrasound guided (TRUS) prostate biopsy is performed for the detection of prostate cancer. Fluoroquinolone has been used as the primary prophylactic agent before biopsy worldwide. However, not negligible number of cases with severe infectious complications caused by fluoroquinolone resistant Escherichia coli (QREC) have been reported recently. We evaluated the outcome of our regimen by targeted prophylaxis using rectal swab culture and investigated characteristics of clinical isolated QREC.

Materials and Methods: This study was done from June 2013 to December 2014. The swabs were cultured on agar plate containing 2 μg/ml levofloxacin and one containing 1 μg/ml sitafloxacin before TRUS guided prostate biopsy. Patients with susceptible organisms received levofloxacin or sitafloxacin while those with resistant organisms received directed antimicrobial prophylaxis according to the results of antimicrobial susceptibility test. All of QREC were susceptible to amikacin and meropenem. We identified the patients with infectious complications after TRUS guided prostate biopsy and backgrounds of QREC carriers from medical reports.

Results: A total of 397 men underwent TRUS guided prostate biopsy. Median age was 69 year-old, median serum PSA levels 7.4 ng/ml, median prostate volume 37.7 ml, respectively. Seventy four (18.6%) patients had QREC. All of QREC were susceptible to amikacin and meropenem. The risk factors of possible QREC were comorbidity with diabetes mellitus and hospitalization within prior 12 months. Three (0.7%) patients of 390 patients received appropriate antimicrobial prophylaxis showed high grade fever after TRUS guided prostate biopsy. However, the pathogens were not QREC.

Conclusion: Targeted antimicrobial prophylaxis could be associated with reducing severe infectious complications caused by QREC. When the patients having potential risk factors being QREC carrier undergo biopsy, rectal swab culture and modified antimicrobial prophylaxis should be considered.