Abstract
Summary
1. The effects of substances derived from Bacillus brevis were tested on protozoa, a leptospira, and on Bartonella bacilliformis. 2. Tyrocidine in a concentration of 5.0 γ per cc markedly inhibited the growth of Leishmania tropica, Trypanosoma cruzi, and Trypanosoma lewisi but not that of either Leptospira icterohemorrhagiae or Bartonella bacilliformis. 3. Tyrothricin killed Trichomonas vaginalis in culture at a concentration of 50 γ per cc of fluid medium. In patients with “trichomonas vaginitis” tyrothricin caused an initial dramatic disappearance of the trichomonads; relapse forms were uninfluenced by further applications. 4. Gramicidin in concentrations of 1.0 γ per cc of culture medium, or less, exerted no apparent adverse effect on the hemoflagellates nor upon Leptospira icterohemorrhagiae or Bartonella bacilliformis. These organisms are all gram-negative. The results obtained extend the correlation between gram-positive staining and gramicidin sensitivity.
Get full access to this article
View all access options for this article.