Experimental studies with T. pallidum Nichols strain – Efficacy of treatment in late infection

Abstract number: 1733_1284

Magalhães Sant`Ana A.C., Rocha G., Poiares da Silva J.

Objective: More than one hundred years since the identification by Schaudinn and Hoffman of Treponema pallidum, the inability to grow it has limited the knowledge of syphilis physiopathology. In the last decades, there has been a marked increase in the number of cases of syphilis and there are still doubts about the total elimination of T. pallidum in the late syphilis. These factors justify the need to continue the studies on T. pallidum infection. To study the efficacy of penicillin and ampicillin treatment in infected

Methods: Rabbits not infected with Treponema paraluiscuniculli were intratesticular inoculated with T. pallidum Nichols strain. They were treated with intramuscullar penicillin and/or ampicillin and monitored by qualitative and quantitative FTAabs. Dark-Field and Transmission Electron Microscopy (ME) was done in testis, popliteus adenitis and ocular aqueous humour.

Results: We detected: (i) In early treatment, FTAabs reverts to negative and in testis the T. pallidum shows lytic aspects with total cure of orchitis. (ii) If the treatment was initiated after 3 months, FTAabs persist positive. However with the maintenance of treatment with ampicillin the title of Ig G decreases to 1/5. (iii) In rabbits that survive until 3 years FTA abs persists positive, but in autopsy we can see in popliteus adenitis but not in testis or in aqueous humor some cells, that in ME shows the morphology of T. pallidum.

Conclusion: We don`t understand the complete meaning of persistence of T. pallidum in late infection because it was not possible to obtain infection with this products in other rabbits. In patients with HIV infection we find an unusual incidence of neurosyphilis, despite adequate therapy. It is of utmost importance to proceed with these studies with new biothecnology.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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