Stimulating effect of leucine on the growth of M. leprae.

M-Y 16j agar slant was prepared by modifying M-Y 14b which has hitherto been used most widely in our experiments by increasing the amount of Na pantothenate and adding leucine, and the growth stimulating effect was investigated referring to the foregoing subculture experiments. The results revealed that the growth of M. leprae was stimulated remarkably in the primary isolation quite similarly to the subculture. This seemed to be resulted from stimulated biosynthesis of fatty acids by the leucine metabolism. The authors are greatly indebted to the World Health Organization and the Comité Exécutif International pour l'Assistance aux Lépreux for their financial support and to Dr. S. Ishihara, the Director of the National Suruga Leprosarium, for his kind supply of the materials to be cultured and for the lepromin test in leprosy patients carried out by himself. The main point of this study was presented to the 50th Annual Meeting of the Japanese Leprosy Association.