Extended-spectrum β-lactamase in the rectal flora of patients undergoing transrectal prostate biopsy: a study of the prevalence in a major metropolitan hospital

Abstract

Objectives: To determine the prevalence of extended-spectrum β-lactamase (ESBL) in patients undergoing transrectal prostate biopsy, to assess the incidence of postoperative sepsis, to correlate the development of sepsis with the presence of preoperative ESBL on rectal swabs, and to assess the adequacy of prophylactic antibiotic guidelines in the context of local ESBL prevalence. Methods: Patients undergoing transrectal ultrasonography (TRUS)-guided biopsy at the Royal Melbourne Hospital between January 2012 and July 2016 had rectal swabs taken immediately prior to TRUS with specific cultures to identify the presence of ESBL. Patients were given a prophylactic antibiotic, 500 mg oral ciprofloxacin, 1 h before the TRUS procedure. Data were collected prospectively, with retrospective review of all readmitted patient files and audit data to ensure complete capture of events. Results: A total of 387 TRUS-guided biopsy procedures were performed. Rectal swabs were correctly collected in 352 patients (91%). The median patient age was 65 years. In all, 25 (7%) ESBL-positive swabs were identified. Most ESBL were Escherichia coli. Half (50%) of ESBL were resistant to ciprofloxacin and all were sensitive to meropenem. A small increase in ESBL prevalence over time was not significant (R2 = 0.35). Four patients (1.1%) were readmitted with sepsis; ESBL Pseudomonas had previously grown in one patient, but sepsis was attributable to non-ESBL E. coli. In one of the readmitted patients ESBL E. coli was present, but this patient did not have ESBL preoperatively. There were no deaths or high-dependency/intensive care unit admissions. Conclusions: This study represents the largest Australian series to investigate ESBL prevalence, and reveals a rate lower than that of many other nations. Our sepsis rate is lower than many international series, perhaps because of our low ESBL rate and strict antibiotic prophylaxis. Preoperative swab results did not predict postoperative sepsis, and the process was therefore not useful for guiding antibiotic therapy. In this patient population, TRUS biopsy, with ciprofloxacin prophylaxis, remains a safe option for diagnostic prostate biopsy.