Lipid composition and virulence of Mycobacterium tuberculosis H37Rv.

The total lipids increased with decrease in total phospholipids in Mycobacterium tuberculosis H37Rv grown at 30 degrees as compared to 37 degrees. Oleic and elaidic acid supplemented to the growth medium resulted in a higher total lipid and phospholipid content, but the content was lower in cells grown in the presence of palmitoleic acid. Cellular content of mannophosphoinositides decreased, whereas that of phosphatidylethanolamine and cardiolipin increased at the lower temperature. A decrease in mannophosphoinositides and an increase in cardiolipin were noted with all fatty acid supplements; however, phosphatidylethanolamine behaved differently. The unsaturated to saturated fatty acids ratio increased at low temperature with oleic and elaidic acid supplements, but it decreased with palmitoleic acid. Cells from media supplemented with palmitoleic acid were found to be most virulent to guinea-pigs. Possible correlation of altered lipid composition and virulence of M. tuberculosis H37Rv has been discussed.