Detection of Neisseria gonorrhoeae from Male Patients with Urethritis by Polymerase Chain Reaction

A polymerase chain reaction (PCR) procedure was developed for detection of Neisseria gonorrhoeae. Two oligonucleotides based on sequences within a 16S ribosomal RNA gene from N. gonorrhoeae were used as extension primers for the PCR. A single DNA fragment of 206 bp was amplified, when N. gonorrhoeae DNA was template for the PCR. No amplified product was detected in Chlamydia trachomatis DNA, Ureaplasma urealyticum DNA or other bacterial DNAs. The DNA fragment of 206 bp was detected on agarose gel electrophoresis, when DNA of greater than or equal to 6.5 N. gonorrhoeae per PCR was used as template DNA for the PCR. The culture and the PCR were carried out for detection of N. gonorrhoeae in 67 urethral swabs obtained from male patients with urethritis. In 27 of 28 specimens in which N. gonorrhoeae was isolated and identified by the culture, 206 bp DNA fragment was amplified by the PCR, but in one specimen no DNA fragment was detected. In 2 of 39 culture-negative specimens, 206 pb DNA fragment was detected and in the remaining specimens, PCR was negative for N. gonorrhoeae. The overall detection coincidence rate between the culture and the PCR was 95.5% (64/67). Thus, the PCR procedure developed in this study was sensitive and specific for detection of N. gonorrhoeae and could be applied for diagnosis of gonococcal urethritis.