Growth of Mycobacterium leprae in a redox system

Mycobacteria recovered from human lepromatous nodules and presumably M. leprae, have been grown in a medium that ensured a minimal oxygen tension at initiation of growth, and an increasing availability of oxygen as bacillary growth increased requiring marginal increments in oxygen tension. This physicochemical environment was achieved by the addition of strong biological reductants in the medium, and a combination of partial vacuum and alkaline pyrogallol in the culture vessel. In addition, n-tetradecane, a straight chain hydrocarbon, and lipids like Cholesterol and Lecithin, all three substances mixed in the aqueous medium as liposomes, were added and found to be useful. Menadione, or Vitamin K3, added to the medium considerably improved growth efficiency. Growth occurred initially as non-acid fast coccoids and bacilli that gradually changed to acid-fast bacilli and globi, and cell-wall deficient, spherical L-form elements. Appearance of growth in any form was perceptible within 1 to 2 weeks and optimal growth as acid fast bacilli took upto 3 months. Both the acid fast and non-acid fast bacilli could not be grown in conventional media, but the non-acid fast coccoids could be readily isolated from these cultures in a specially enriched liquid medium. The problem of harvesting of the growth free of lipid-hydrocarbon substances has still not been solved, as also an optimum oxidation-reduction potential. The growth is transferable.