Predictors of Fluoroquinolone-Resistant Bacteria in the Rectal Vault of Men Undergoing Prostate Biopsy

Importance Fluoroquinolone (FQ)-resistant rectal vault flora is associated with infectious complications in men undergoing transrectal ultrasound-guided prostate needle biopsy (TRUS-PNB). Objective To determine the patient factors that predict FQ-resistant rectal cultures in men who are undergoing transrectal ultrasound-guided prostate needle biopsy. Methods An IRB approved retrospective review of 6183 consecutive men who had undergone a rectal swab culture in preparation for TRUS-PNB between January 2013 and December 2014 was performed. Multivariable logistic regression was used to determine the clinical and demographic factors associated with FQ-resistant Enterobacteriaceae in the rectal vault. Results Of the 6179 rectal swabs analyzed, 4842 (78%) were FQ-sensitive, and 1337 (22%) were FQ-resistant. On univariable analysis, increasing age, prior TRUS-PNB, higher number of biopsy cores obtained, diabetes mellitus, antimicrobial use within the past 6 months and non-Caucasian race were predictors of FQ-resistance (all p < 0.05). Men with FQ-resistant cultures were more likely to have benign pathology on TRUS-PNB ( p = 0.004). On multivariable analysis, increasing patient age (OR = 1.01/year [1.00–1.02]), use of antimicrobials in the last 6 months (OR = 2.85[2.18–3.72]), African American (OR = 1.99 [1.66–2.37]), Asian (OR = 3.39 [2.63–4.37]), and Hispanic (OR = 2.10 [1.72–2.55]) races were independently associated with FQ-resistant rectal cultures. The overall infectious rate was 1.1% (56/5214) and the sepsis rate was 0.46% (24/5214). The infection rate in the FQ-resistant group was 3.9% (43/1107) compared to FQ-sensitive group 0.3% (13/4107), p < 0.001. Conclusion In this cohort, increasing age, recent antimicrobial-use, and non-Caucasian race were independent predictors of FQ-resistance in the rectal vault. As FQ-resistance is associated with infectious complications from transrectal ultrasound-guided prostate needle biopsy, understanding risk factors may assist infection control efforts.