Rectal Swabs Demonstrate High Levels of Ciprofloxacin Resistant Escherichia coli among Patients Undergoing Prostate Biopsies in San Fernando, Trinidad and Tobago

Objectives: To establish the prevalence of ciprofloxacin resistant Escherichia coli in the fecal carriage of patients undergoing trans-rectal ultrasound (TRUS) guided prostate biopsy.

Methodology: From August 2014 to January 2015, all patients undergoing trans-rectal ultrasound guided prostate biopsy at the San Fernando Hospital had rectal swabbing done. Also, data regarding demographics, recent hospitalization and antibiotic use, prior biopsy, diabetes mellitus and indwelling urinary catheters were prospectively collected. The cultures were incubated in Blood and MacConkey agar and E. coli isolates are tested for antibiotic sensitivity using the Kirby-Bauer method and the Microscan automated system. All isolates of Escherichia coli were tested for sensitivity to ciprofloxacin and other antibiotics commonly used in urological practice. Patients were followed for 4 weeks post biopsy for complications. Data were recorded in Microsoft Excel and analyzed using SPSS version 20.

Results: 100 patients had rectal swabs taken, and 70 cultures were positive for Escherichia coli with 36 (51%) being resistant to ciprofloxacin and 58% (21/36) of these isolates being multi-drug resistant as defined by resistance to 3 or more classes of antibiotics. Resistance to other antibiotics commonly used in urological practice was also identified: gentamicin 28% (19/67), amoxicillin/clavulanate 34% (24/70), piperacillin/tazobactam 11% (8/70), trimethoprim/ sulfamethoxazole 28% (17/61) and ceftriaxone 27% (16/60). There was a trend towards increased resistance among patients with indwelling catheters and recent antibiotic use.

Conclusion: There is a high prevalence of ciprofloxacin resistant Escherichia coli in the fecal carriage of patients undergoing TRUS guided prostate biopsy and the current prophylaxis policy may need to be revised.