In vitro Leprocidal Activity of Some Non-chaulmoogryl Compounds. ∗

Abstract

Little emphasis has been placed upon the in vitro bactericidal activity against Mycobacterium leprae of compounds other than the fixed and essential oils and various fatty acids examined by Walker and Sweeney, Schöbl, and Adams and his co-workers, 1 In view of the recent interest in the clinical use of non-chaulmoogryl compounds, particularly certain dyes, as antileprosy drugs, a report of our accumulated findings on the action of these and other agents against M. leprae is made herewith. These observations have been made during the past year as a tentative guide to therapeutic efforts on experimentally infected leprous rats using a standardized technique previously described.²

The leprocidal activity of over 200 chemical agents falling into 4 general types has been studied by the 2 appropriate techniques described by Adams et al., 1 with careful adherence to the precautions noted by these authors. A single strain of test organism was used, this being M. leprae hominis, Mary Puhulahula strain, isolated by Dr. E. L. Walker.† The media used as substrate in the tests was that of Long and Seibert, 3 recommended for our use by Dr. Walker, rather than a 5% glycerol broth as used by Adams 1 in his tests. No other variations from Adams'method were made. Most of the tests were carried out in Dr. Walker's laboratory and in conjunction with the Bacteriological Laboratory of the University of California. By closely following the bacteriological technique worked out by Adams, his estimate of a probable error of ±10% appears justified.