Comparative study of the lipid composition of particular pathogenic and nonpathogenic species of Mycobacterium.

A comparative study was undertaken of lipid composition of Mycobacterium tuberculosis H(37)Rv and H(37)Ra, M avium, M phlei, and M 607. Neutral lipids and phosphatides constituted about 55 and 25 percent of the total lipids, respectively. Seven different phosphatides were isolated and identified in varying proportions in all of the above species of mycobacteria. These were polyglycerophosphatide, phosphatidic acid, phosphatidylethanolamine, lysophosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol dimannoside, and phosphatidylinositol pentamannoside. Choline-containing phosphatides and cholesterol (steroids) were not detected in lipids of any of the five species under these defined experimental culture medium and growth conditions. Interestingly enough, neutral lipids of M tuberculosis (H(37)Rv and H(37)Ra) contained a higher percentage of diglycerides than monoglycerides, whereas in the other species (M avium, M phlei, and M 607) the monoglyceride content exceeded that of the diglycerides. It appears that the lipid composition of mycobacteria can be an additional useful parameter in distinguishing pathogenic from nonpathogenic species of mycobacteria.