Treatment of Experimental Syphilis in Rabbits with Streptomycin

Summary

1. Two syphilitic rabbits were treated with streptomycin for 72 hours and 96 hours respectively, with 42.5 mg per kg and 45.5 mg per kg per day respectively. 2. Darkfield examinations were positive at the end of 24 and 48 hours of treatment and transfers of testicular material from both rabbits caused syphilitic lesions in other rabbits in 40 days. 3. Darkfield examination was negative after 72 hours of treatment in the rabbit which had received 42.5 mg of streptomycin per kg per day. Transfer of one of this rabbit's testicles to 2 rabbits failed to cause syphilitic changes. 4. The rabbit which was treated for 96 hours with 45.5 mg of streptomycin per kg per day showed non-motile spirochetes which were capable of causing syphilis in 2 rabbits. However, the lesions did not develop until 120 days after inoculation. 5. Popliteal transfers of the streptomycin-treated rabbits, performed 6 months after therapy, failed to cause syphilitic lesions in 141 days. The control's popliteal nodes caused changes in 41 days. 6. The quantitative Kahn reaction for syphilis showed a rapid drop in the rabbits which had received streptomycin. This eventuated in negativity whereas the control remained positive. 7. The results obtained in this preliminary experiment justify further investigation of the effects of streptomycin in experimental syphilis.