Large study supports pre-prostate biopsy rectal cultures 

Editor's note: This article has been updated since its original publication to include additional study data and commentary from the author/presenter.

Orlando, FL—Rectal colonization with a fluoroquinolone-resistant (FQR) organism identifies men who are at significantly increased risk for an infectious complication following prostate biopsy, according to the findings of a recent multi-institutional international collaborative study.

The investigation, which was conceived by first author Michael Liss, MD, was a retrospective analysis of several prospective studies investigating men who had a rectal swab for culture prior to prostate biopsy but whose antibiotic prophylaxis was not guided by the culture results. Six institutions participated and provided data for 2,673 men whose procedures were performed from 2007 through 2013.

Of the overall population, 92% of men received a fluoroquinolone for prophylaxis and 27% received an augmented regimen that included additional antibiotics. About 20% of men had an FQR-positive rectal culture, 2.6% developed a post-biopsy infection, and 1.6% had an infection-related hospitalization.

Compared to men whose rectal culture was negative for an FQR organism, those who were FQR culture positive had a significantly higher rate of infection (6.6% vs. 1.6%) and hospital admission for infection (4.4% vs. 0.9%). The associations were more pronounced when considering men who received antibiotic prophylaxis with only a fluoroquinolone (1,876 men). In the latter subgroup, the infection rate was 8.2% among men who were FQR positive versus 1.8% in those who were FQR negative, and the rates of infection-related hospital admission in the FQR-positive and FQR-negative men were 6.1% and 1.1%, respectively.