[Detection of Treponema pallidum DNA and RNA in clinical material from patients with syphilis at different stages]

The results of the development and approval of methods for the detection of T. pallidum DNA and 16S rRNA in clinical material (blood plasma, serous exudates) are presented. T. pallidum DNA was detected with the use of primers to the gene coding protein with a moleculat weight of 47 kD and T. pallidum RNA, with the primers to gene 16S rRNA. The isolation, reverse transcription and amplification of DNA and RNA was carried out in the presence of inner DNA and RNA control respectively. The analytical sensitivity of the developed method was 400 DNA copies per ml. The characteristics of analytical and diagnostic specificity were 100%. The specimens of blood plasma, taken from 292 patients with syphilis at different stages before specific antibacterial therapy, were tested by the PCR. The detection rate of T. pallidum DNA and RNA in blood plasma was, respectively, 91% and 100% in primary seropositive syphilis, 68% and 79% in secondary early syphilis, 19% and 26% in latent unverified syphilis. In secondary relapsing syphilis T. pallidum DNA and RNA were detected in 92% and in latent early syphilis, in 14% of patients. T. pallidum nucleic acids were detected in 1 patient at the seronegative period of primary syphilis. No positive result was obtained in the PCR analysis in any of the patients with diagnosed seroresistance, latent late syphilis and tertiary syphilis. In the study of material taken from chancres of 11 syphilis patients the data obtained by dark-field microscopy and the PCR analysis completely coincided.