Recently,1 one of us described the successful implantation of spirochetes and the transmission of experimental syphilis to rabbits from the living paretic brain.
At present this experimental syphilis has been transmitted to five generations of rabbits.
The initial inoculation of brain was made into the testis of a large rabbit, June 11, 1915, and thirty-two days later, July 11, large numbers of spirochetes were demonstrable in both testes by aspiration. August 12, about two months after the initial inoculation, the right testis was castrated under aseptic precautions, one portion being used for implantation into other animals, and the remaining portion for cultural experiments.
After thorough maceration with normal saline, the material was planted deep into tubes of rabbit kidney ascitic agar mediums. The cultures were covered with paraffin oil and cultivated under anaerobic conditions. Six tubes were inoculated from this material. Examination of the tubes about four weeks later
WILE UJ, DE KRUIF PH. CULTURAL EXPERIMENTS WITH THE SPIROCHAETA PALLIDA DERIVED FROM THE PARETIC BRAIN. JAMA. 1916;LXVI(9):646–647. doi:10.1001/jama.1916.02580350034013