Routine Ertapenem Prophylaxis for Transrectal Ultrasound Guided Prostate Biopsy does Not Select for Carbapenem Resistant Organisms: A Prospective Cohort Study

Purpose: Sepsis after transrectal ultrasound guided prostate biopsy is an increasing problem in this era of rising antibiotic resistance. Although ertapenem prophylaxis has proved effective at our institution to reduce this, it has raised local and regional antimicrobial stewardship concerns. We investigated the possible selective effect of single dose ertapenem prophylaxis on fecal colonization with carbapenem resistant Enterobacteriaceae. Materials and Methods: Patients underwent a rectal swab prior to receiving prebiopsy ertapenem prophylaxis. A second swab was obtained at followup 4 to 6 weeks later. Swabs were screened for carbapenem resistant Enterobacteriaceae using an enhanced CDC (Centers for Disease Control) method. Prebiopsy swabs were also screened for extended spectrum b-lactamase producing and ciprofloxacin resistant Enterobacteriaceae. Patients were monitored for post-biopsy sepsis. Results: A total of 326 patients were enrolled in the study. At baseline 6.4% and 9.0% of patients had colonization with extended spectrum beta-lactamase producing and ciprofloxacin resistant Enterobacteriaceae, respectively. Carbapenem resistant Enterobacteriaceae were not detected at baseline or followup in any patients. Colonization with nonfermentative organisms with intrinsic ertapenem resistance was detected in 29.4% of patients at baseline and followup (p = 1.0). Three cases (0.9%, 95% CI 0.2-2.8) of probable post-biopsy sepsis were identified during the study period. None was bacteremic or required intensive care unit admission. Conclusions: Single dose ertapenem prophylaxis did not appear to have a significant selective effect on fecal colonization with carbapenem resistant Enterobacteriaceae or other ertapenem resistant gram-negative organisms in this outpatient group. It is highly effective prophylaxis for transrectal ultrasound guided prostate biopsy. In the right setting ertapenem may represent a useful prophylactic option to prevent post-transrectal ultrasound guided prostate biopsy sepsis.