Detection of bacterial signal by 16S rRNA polymerase chain reaction in expressed prostatic secretions predicts response to antibiotic therapy in men with chronic pelvic pain syndrome.

Purpose: Some men with chronic pelvic pain syndrome (CPPS) have evidence of bacteria in their prostatic fluid (expressed prostatic secretions [EPS]) detected by 16S rRNA techniques. In this study, we correlate presence of bacterial signal with response to therapy.

Materials and methods: EPS and first voided urine (VB1) from 47 men with CPPS were analyzed by polymerase chain reaction (PCR) for bacterial signal using universal primers specific for bacterial 16S rRNA. Signal was considered positive if found only in the EPS sample, or if at least 10x stronger in the EPS than in VB1. All patients were treated with antibiotic therapy.

Results: Thirty-three patients were category IIIa (nonbacterial prostatitis) and 14 were category IIIb (prostatodynia). Seventeen of the 33 category IIIa patients had positive localizing cultures for gram-positive bacteria. However, a positive bacterial signal was detected in 23 EPS samples by 16S rRNA PCR. This signal was found in 14 of 17 culture-positive patients, 7 of 16 of the remaining category IIIa patients, and 2 of 14 of category IIIb patients. No patient with negative bacterial signal improved with antibiotic therapy (negative predictive value 100%). Thirteen patients with positive bacterial signal improved with antibiotic therapy.

Conclusions: In men with category III chronic prostatitis/CPPS, bacterial signal detected by PCR can help predict response to antimicrobial therapy.