Molecular epidemiological evidence for ascending urethral infection in acute bacterial prostatitis

PURPOSE: To test the ascending urethral infection in the pathogenesis of acute bacterial prostatitis, we assessed the clonality of Escherichia coli strains isolated from urine and rectal swab of patients with acute bacterial prostatitis using molecular typing methods. MATERIALS AND METHODS: A total of 50 E. coli strains each isolated from urine and rectal swabs of 9 men with acute bacterial prostatitis at diagnosis were examined for 6 urovirulence determinant profiles and pulsed field gel electrophoresis patterns. In 1 case E. coli isolates from the rectal swab of the patient's wife were also examined at diagnosis and after 5 weeks. RESULTS: The urovirulence profile and pulsed field gel electrophoresis demonstrated that causative E. coli was monoclonal in each case, and present in the rectal swab as a predominant (96% to 100%) fecal clone in 2 and a minority clone (2% to 8%) in 4. Furthermore, causative E. coli dominated in the rectal swab of the 1 patient's wife. CONCLUSIONS: Our results are consistent with the ascending route of infection in acute bacterial prostatitis. However, causative E. coli might possibly originate from either intestinal reservoir of the host or household member. Owing to limitations of the cross-sectional design of this study, longitudinal studies are necessary to establish the ascending route of infection in this disease.