OBJECTIVES To study the clinical and bacteriologic Picture of acute prostatitis caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli after transrectal ultrasound-guided prostate biopsy. METHODS The retrospective data from 1339 patients who had undergone transrectal ultrasound-guided biopsy from November 2003 to June 2008 were reviewed. An automatic biopsy gun with an 18-gauge needle was used to obtain 10-core biopsies for first biopsies and >= 12-core for repeat biopsies. These patients had received 500 mg ciprofloxacin orally twice daily for 5 days, beginning 24 hours before biopsy. All biopsies were performed as Outpatient procedures. RESULTS Of the 1339 patients, 28 (2.1%) had acute bacterial prostatitis detected after transrectal ultrasound-guided prostate biopsy. Acute prostatitis Occurred after the first biopsy in 15 patients (1.3%) a ad after repeat biopsy in 13 (6.8%). The patients had developed infective symptoms a mean of 3 days after transrectal ultrasound-guided prostate biopsy. Of the 28 patients, 17 (61%) had positive urine and/or blood cultures, including E. coli in 14. Of the 14 patients, 6 had acute prostatitis caused by ESBL-producing E. coli. Bacteria isolated from urine were tested for drug susceptibility to a wide range of antibiotics. All patients with ESBL-producing E. coli were treated with imipenem. The bacteria detected in these urine cultures were resistant to ciprofloxacin, ceftriaxone, sulbactam/ampicillin, and cefazolin. Imipenem and piperacillin-tazobactam were the most active agents against ESBL-producing E. coli. ESBL-producing isolates had a significant reduction in activity for most antimicrobial agents, including fluoroquinolones and amikacin. CONCLUSIONS The prompt initiation of effective antimicrobial treatment is essential in patients with ESBL-producing E. coli, and empirical decisions Must be determined by knowledge of the local distribution of pathogens and their susceptibility. UROLOGY 74: 119-124, 2009. (c) 2009 Elsevier Inc.