Summary:
Available methods for direct diagnosis of syphilis are summarized with emphasis being on those
promising for routine use.
Direct detection of the causative agent T. pallidum is limited since the agent is not able to synthesize
enzyme cofactors, fatty acids and nucleotides de novo, is completely dependent on its host and thus
culture on synthetic media is not feasible. Direct diagnosis of syphilis is based on rabbit infectivity
testing (RIT), dark field or fluorescent microscopyandrecently also onmolecular biological methods
used with increasing frequency in routine practice. Suitability and usability of different methods
for direct detection of T. pallidum at different stages of syphilis are explained. Except for molecular
biological methods, most of detection techniques can only be used at the primary and secondary
stages or in early congenital syphilis.
Major PCR methods for diagnosis of syphilis are presented. Not all of them are suitable for use in
routine practice owing to differences in their sensitivity and design. The polA PCR method appears
to be the most promising in this regard.
Key words:
syphilis – Treponema pallidum – direct detection – polA PCR.
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