Levofloxacin resistant Escherichia coli sepsis following an ultrasound-guided transrectal prostate biopsy: report of four cases and review of the literature. 
Fluoroquinolones are the most commonly used prophylactic antimicrobials for ultrasound-guided transrectal prostate biopsy due to their broad pathogen spectrum, pharmacokinetics, bioavailability and ease of oral administration.  However, although Escherichia.  coli (E. coli) is the most common pathogen associated with infections after transrectal prostate biopsy, the prevalence of fluoroquinolone resistant strains of E. coli is increasing.  Levofloxacin resistant E. coli sepsis occurred in four (0.6%) of 665 patients who received oral levofloxacin prophylaxis and underwent transrectal prostate biopsy from July 2002 to December 2006 in this institute.  All patients had obstructions of the lower urinary tract and three of the four had a history of previous use of quinolones.  Although two of the four patients developed septic shock, all of the patients were treated with carbapenems immediately and made a complete recovery.  Since a case of multiresistant E. coli sepsis and fatal anaerobic sepsis after transrectal prostate biopsy had been reported, intravenous carbapenem is recommended as antimicrobial therapy for sepsis after transrectal prostate biopsy.