The demonstration by Nelson and Mayer (1949) of an antibody in syphilitic sera that immobilizes virulent Treponema pallidum in the presence of complement in vitro led to the development (Nelson and Mayer, 1949; Nelson and Diesendruck, 1951) of a T. pallidum immobilization (TPI) test for use in the case of individuals who might repeatedly give a positive reaction to other tests for syphilis but ...

Rabbits stimulated with Mycobacterium bovis (strain BCG) one month before challenge with Treponema pallidum (Nichols) did not show any modification in their development of syphilitic lesions. A second infection with BCG given at the same time and at the same intradermal site as the T. pallidum challenge also failed to protect the rabbits against syphilis. Thus the non-specific activation of cel...

According to Nelson (1953), " the immune-adherence phenomenon" is concerned with the specific attachment which occurs between erythrocytes and micro-organisms which are sensitized by antibody (Ab) and Complement (C'). Measurements of immune-adherence (IA) may be performed by counting the Treponema pallida remaining in the fluid phase of reaction mixtures containing T. pallida, Ab, C', and eryth...

Treponema pallidum PCR (Tp-PCR) has been noted as a valid method for diagnosing syphilis. We compared Tp-PCR to a combination of darkfield microscopy (DFM), the reference method, and serologic testing in a cohort of 273 patients from France and Switzerland and found the diagnostic accuracy of Tp-PCR was higher than that for DFM.