Action of Penicillin and Other Antibiotics on Treponema Pallidum.

Summary

The test for spirocheticidal action of drugs in vitro (Eagle²) has been used with certain antibiotic substances. Penicillin, originally presumed to be inactive in vitro, has proved to be active under these conditions in the relatively high concentration of 800 to 1600 Oxford units per 0.8 ml. Inadequate therapy of syphilis in a rabbit resulted in the production of a more resistant strain of Treponema pallidunz and emphasizes the importance of adequate initial therapy.