OBJECTIVESTo investigate the cause of chronic pelvic pain syndrome (CPPS) and the correlation between presence of bacterial signal and the response to antibiotics by detecting bacterial 16S rRNA gene signal using polymerase chain reaction (PCR).

METHODSEPS and first void urine (VB1) from 59 men with CPPS were analyzed by PCR for bacterial signal using universal primers specific for bacterial 16S rRNA gene. If the bacterial signal was found only in EPS or the EPS bacterial signal was at least 10 times stronger than the VB1 one, positive result could be decided for bacterial signal detection. All patients were treated with levofloxacin and azithromycin for 4 weeks. The treatment could be considered effective if more than 50% improvement, compared to the state before the treatment, was achieved in the symptom severity index(SSI), symptom frequency questionnaire(SFQ), national institutes of health chronic prostatis symptom index of pain(quasi-CPSI) or the patients' general subjective assessment.

RESULTSPositive bacterial signal was detected in 46 of the 59 CPPS patients; The difference of improvement rates between positive bacterial signal group and negative bacterial signal group, which were 65%-74% and 0 respectively, was significant.

CONCLUSIONSThe basis of detecting 16S rRNA gene signal by PCR in clinical practice was built. The study shows that bacterial infection is related to CPPS. Bacterial signal detection results can help predict the effect of antimicrobial therapy.