Immunological studies on treponemal antigens. II. Serological changes and resistance to infection in rabbits immunized with culture supernatant of avirulent Treponema pallidum.

In a previous paper, Izzat, Smith, Jackson, and Knox (1971) reported the isolation of an antigenic substance from the supernatant of cultures of avirulent Treponema pallidum. The antigenic sub- stance was shown to be nontoxic and glycoprotein in nature. Injections of this material into rabbits stimulated precipitin antibodies reactive with FTA-ABS desiccated antigen.