title: Prevalence of antibiotic-resistant bacteria on rectal swabs and factors affecting resistance to antibiotics in patients undergoing prostate biopsy.
abstract: OBJECTIVE
  The prevalence of antibiotic-resistant bacteria on rectal swabs in patients undergoing transrectal ultrasound (TRUS)-guided prostate biopsy and the factors affecting resistance to antibiotics were evaluated.
  
  
  METHODS
  Two hundred twenty-three men who underwent TRUS-guided prostate biopsy from November 2011 to December 2012 were retrospectively evaluated. Rectal swabs were cultured on MacConkey agar to identify antibiotic-resistant bacteria in rectal flora before TRUS-guided prostate biopsy. All patients were admitted and received intravenous antibiotics before prostate biopsy. Clinical variables including underlying disease, infectious complications, and antibiotics associated with resistance were evaluated. Logistic regression was used to determine the factors influencing antibiotic resistance.
  
  
  RESULTS
  Of the 233 patients, 161 had positive rectal cultures. Escherichia coli was cultured in 130 (80.7%) and Klebsiella pneumonia in 16 (9.9%). The prevalence of quinolone resistance was 16.8% and the prevalence of extended-spectrum beta-lactamase (ESBL) positivity was 9.3%. A previous history of prostatitis was correlated with quinolone resistance and ESBL positivity (both p=0.001). The factors affecting quinolone resistance in the univariate analysis were a previous history of prostatitis (p=0.003) and previous exposure to antibiotics (p=0.040). Only a previous history of prostatitis was statistically significant in the multivariate analysis (p=0.014). Four patients had infectious complications.
  
  
  CONCLUSIONS
  The prevalence of quinolone resistance was 16.8% in rectal swabs performed before TRUS-guided prostate biopsy. A previous history of prostatitis was influential. In patients with a history of prostatitis, selection of prophylactic antibiotics before the biopsy may be reconsidered.
authors.affiliation: Department of Urology, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Jong Beom
authors.initials: JB
authors.lastname: Kim
authors.affiliation: Department of Urology, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Seung Il
authors.initials: SI
authors.lastname: Jung
authors.affiliation: Department of Urology, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Eu Chang
authors.initials: EC
authors.lastname: Hwang
authors.affiliation: Department of Urology, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Dong Deuk
authors.initials: DD
authors.lastname: Kwon
keywords: Bacteria; Biopsy; Drug resistance; Prostate; Risk factors