[Detection of Chlamydia trachomatis from urethral swab in male urethritis by polymerase chain reaction].

A polymerase chain reaction (PCR) with Chlamydia trachomatis-specific primers was applied for detection of C. trachomatis from urethral swab in male urethritis. The results were compared with those of culture method for detection of C. trachomatis. Of 18 clinical specimens tested in this study, inclusion bodies of C. trachomatis were detected in 11 specimens by the culture method. For PCR, sample DNA was prepared from transport medium in which urethral smear was suspended and two oligonucleotides based on sequences within the major outer membrane protein gene from C. trachomatis serovar L2 were used as extension primers. In 12 of the 18 specimens, 242bp DNA fragment was amplified by PCR and demonstrated to be the DNA fragment of C. trachomatis by Southern blot hybridization. No DNA of 242bp was amplified by PCR from five specimens in which any inclusion bodies of C. trachomatis were observed or from a specimen in which one inclusion body per cover slip was detected by culture method. C. trachomatis DNA of 242bp was amplified from all specimens in which 14 and more inclusion bodies per cover slip were detected by culture method. In two specimens concluded s negative by culture method, amplified C. trachomatis DNA were detected by PCR. Thus, the PCR would be a more simple and sensitive method for detection of C. trachomatis, compared with the culture method.