Antigenic cross-reactivity between Borrelia burgdorferi, Borrelia recurrentis, Treponema pallidum, and Treponema phagedenis.

The antigenic cross-reactivity between different Borrelia and Treponema species was determined by the indirect immunofluorescence antibody test and sodium dodecyl sulphate-polyacrylamide gel electrophoresis followed by immunoblotting. The protein profiles of Borrelia burgdorferi, Borrelia recurrentis, Treponema pallidum, and Treponema phagedenis revealed essential differences. Using immunoblotting, rabbit immune sera to B. burgdorferi and B. recurrentis exhibited strong cross-reactivities to heterologous borrelial antigens and, to a lesser extent, to treponemal antigens. Immune sera to T. pallidum and T. phagedenis reacted with heterologous treponemal antigens, but exhibited lesser cross-reactivities to borrelial antigens. Five B. burgdorferi and seven T. pallidum major antigens were not cross-reacting with antisera raised against T. pallidum and B. burgdorferi, respectively. However, absorption of the investigated antisera with a T. phagedenis ultrasonicate eliminated cross-reacting borrelial and treponemal antibodies.