Prevalence and predictive factors of harboring fluoroquinolone-resistant and extended-spectrum β-lactamase-producing rectal flora in Hong Kong Chinese men undergoing transrectal ultrasound-guided prostate biopsy.

Objective: To study the prevalence of fluoroquinolone-resistant (FQ-resistant) and extended-spectrum β-lactamase-producing (ESBL-producing) bacteria in the rectums of patients undergoing transrectal ultrasound-guided prostate biopsy (TRUS-Bx), identifying predictive factors for such carriage and to correlate with the microbiology of those who developed postbiopsy infection (PBI).

Methods: A total of 371 men undergoing TRUS-Bx were prospectively enrolled from August 2011 to March 2012. Rectal swab was obtained before antimicrobial prophylaxis on the day of biopsy and grown in selective media for resistant bacteria. Standard FQ prophylaxis was used without guidance from rectal swab results. Univariate and multivariate analyses were performed to identify predictive factors of either FQ-resistant or ESBL-producing bacteria carriage.

Results: A total of 199 of 371 patients (53.6%) carried antimicrobial-resistant rectal flora, with 150 (40.4%) and 152 (41.0%) patients having FQ-resistant and ESBL-producing bacteria, respectively. Diabetes mellitus (odds ratio, 2.075; P = .028) and the use of antimicrobials within the prior 5 years (odds ratio, 1.550; P = .047) were independent predictors of rectal carriage of such flora. PBI occurred in 9 patients, of which 7 harbored prebiopsy antimicrobial-resistant bacteria, which completely matched the microbiological data collected during the patients' PBI episodes.

Conclusion: A high prevalence of FQ-resistant and ESBL-producing rectal flora in Chinese men undergoing TRUS-Bx was found. Diabetes mellitus and prior antimicrobial use within 5 years were significant predictors for resistant bacterial carriage. Despite the high-resistant bacteria prevalence, PBI rate remained low. A targeted approach of antimicrobial prophylaxis using prebiopsy culture swab in areas with high prevalence of resistant bacteria should be further investigated.