DETECTION OF C-TRACHOMATIS IN UROGENITAL SPECIMENS BY POLYMERASE CHAIN-REACTION

Objective - To establish a polymerase chain reaction (PCR) protocol for the detection of urogenital C trachomatis infection and to compare it with the detection in cell culture. Specimens - Urethral specimens were collected from 62 male patients and cervical specimens from 106 female patients. Setting - Department of Dermatology and Venereology, Ruprecht-Karls-Universitat, Heidelberg. Methods - Urogenital specimens were simply boiled for 15 minutes and subsequently subjected to amplification without prior extraction of nucleic acid. The DNA sequence selected for amplification is located in the third open reading frame of the ubiquitous C trachomatis plasmid pCTT1. The amplified products were demonstrated by agarose gel electrophoresis followed by Southern blot hybridization. In addition, specimens were investigated with cell culture. Main outcome measures - Results of PCR and cell culture. Results - PCR detected all C trachomatis serovars relevant for urogenital infections (DL2). Serial dilution experiments revealed that the PCR procedure was 100 fold more sensitive than cell culture. The investigation of 168 urogenital specimens showed that the PCR confirmed all 30 cell culture positive results, however, out of the 138 cell culture negative specimens 16 were positive using the PCR. Conclusions - A substantial number of urogenital C trachomatis infections detectable by PCR may be missed by the cell culture technique.