The lipids ofMycobacterium tuberculosis BCG: Fractionation, composition, turnover and the effects of isoniazid

Prolonged exposure of Mycobacterium tuberculosis to isoniazid has been found to reduce the amount of extractable lipid, particularly lipid solubilized by cold methanol 1. It has been reported 2 that exposure of Mycobacterium avium to isoniazid for short periods leads to an increase in extractable lipid and to a decrease in the amount of fatty acid, with a reduction in the amounts of these fatty acids of chain length greater than C,, relative to the amounts of palmitic and stearic acids. There is also evidence that isoniazid produces an immediate slight inhibition of the incorporation of acetate into M. tuberculosis and a considerable inhibition after eight days 3, and there is also a report' that isoniazid inhibits the incorporation of acetate by cell-free extracts of M. avium into fatty acids, though this was not found with extracts of M. tuberculosis or Mycobacterium smegmati~ ~.