Login to Access Video or Poster Abstract: MP11-15
Sources of Funding: none

Introduction

Fluoroquinolone (FQ)-resistant rectal vault flora has been associated with increased infectious complications in men undergoing transrectal ultrasound guided prostate needle biopsy (TRUS-PNB). We sought to determine the patient-related factors that predict FQ-resistant rectal swabs in men with an indication for TRUS-PNB.

Methods

A retrospective review was performed on 5,271 consecutive patients who underwent rectal swabs before TRUS-PNB across 28 urology clinics around Chicago from January 2013 to December 2014. One microbiology lab processed all swabs, immersed them in a ciprofloxacin broth, and cultured them on MacConkey agar to isolate gram-negative rods. After incubation, FQ-resistant organisms were subcultured and underwent additional sensitivity testing. Characteristics of patients with and without FQ-resistant swabs were compared using the Kruskal Wallis and Chi-square tests. Multivariable logistic regression was performed to determine predictors of FQ resistance. Analyses were performed using R version 2.14.2 (R Foundation for Statistical Computing, Vienna, Austria).

Results

Of the 5,271 rectal swabs analyzed, 4,164 (79%) were FQ sensitive, and 1,107 (21.0%) were resistant. On univariable analysis, increasing age, diabetes mellitus, antibiotic use within the past 6 months, and non-Caucasian race were predictors of FQ resistance (all p < 0.05). The number of prior biopsies, indwelling foley catheter, healthcare profession, and PSA were not predictors. FQ resistance was also associated with benign biopsy histology (p < 0.01). On multivariate analysis, increasing patient age (OR=1.01/year [1.0-1.02]), use of antibiotics in the last 6 months (OR=2.75[2.06-3.67]), Black (OR=2.08 [1.72-2.54]) and Hispanic (OR=2.13 [1.72-2.64]) races remained statistically significant.

Conclusions

In this cohort increasing age, recent antibiotic-use, and Black and Hispanic races were independent predictors of FQ-resistance in the rectal vault. The higher likelihood of benign histology suggests that BPH or inflammation may be additional predictors and require further study.

Funding

none