Diagnosis of gonococcal urethritis and chlamydial urethritis by polymerase chain reaction

Abstract

A polymerase chain reaction (PCR) method was compared to standard methods (cultures for Neisseria gonorrhoeae and Chlamydia trachomatis and an enzyme-immunoassay for C. trachomatis) in diagnosis of gonococcal and chlamydial urethritis in 40 male patients with urethritis. Gonococcal urethritis was diagnosed by detection of a 206 bp DNA fragment amplified by PCR with N. gonorrhoeae-specific primers. Chlamydial urethritis was diagnosed by detection of a 242 bp DNA fragment amplified by PCR with C. trachomatis-specific primers. Gonococcal and chlamydial urethritis, gonococcal and non-chlamydial urethritis, non-gonococcal and chlamydial urethritis, and non-gonococcal and non-chlamydial urethritis were diagnosed in 8, 10, 14 and 8 patients, respectively, by the PCR method. In 9 patients with gonococcal and chlamydial urethritis, 10 with gonococcal and non-chlamydial urethritis, 12 with non-gonococcal and chlamydial urethritis, and 9 with non-gonococcal and non-chlamydial urethritis, diagnosed by the standard methods, the coincidence rates of the PCR to the standard methods were 78% (7/9), 90% (9/10), 100% (12/12), and 89% (8/9), respectively. The overall coincidence rate between the PCR and the standard methods in diagnosis of urethritis were high (90%). In addition, N.gonorrhoeae and C.trachomatis could be simultaneously detected from one urethral sample in approximately 6 hours by means of the PCR. Thus, the PCR method could clinically be applied and would offer several advantages to diagnosis of urethritis, compared to the standard methods.