EXPERIMENTAL-INFECTION OF THE MOUSE-BRAIN BY A RELAPSING FEVER BORRELIA SPECIES - A MOLECULAR ANALYSIS

The spirochetal disease relapsing fever is notable not only for multip hasic antigenic variation but also for central neurologic manifestatio ns. To further characterize involvement of the brain in this disorder, immunocompetent and -deficient mice were infected with Borrelia herms ii. Immunodeficient mice were treated while spirochetemic with neutral izing IgM monoclonal antibodies to the infecting serotype. Blood, cere brospinal fluid, and brain tissue were examined by culture and polymer ase chain reaction. In immunocompetent mice, antigenic variation occur red in the brain as well as in the blood. In immunodeficient mice, the infecting serotype was still present in the brain after it had been e liminated from the blood by the administered antibodies. These latter results cannot be accounted for by contamination of brain tissue and c erebrospinal fluid by blood and. hence, establish the direct involveme nt of the central nervous system in this experimental infection.