Resistance-enhancing compound from Mycobacterium tuberculosis.

A soluble, high molecular weight, resistance-enhancing compound was isolated from Mycobacterium tuberculosis by fractionation of a dimethylsulfoxide extract of the organism with n-decyl alcohol. The compound contained carbohydrate, protein, fatty acids, and phosphorous. Resistance enhancement was nonspecific in that protection was afforded toward infection with Klebsiella pneumoniae as well as M. tuberculosis. The compound enhanced the rate of clearance of carbon from the blood of mice and depressed the immune response of animals to injected sheep red blood cells. No manifestations of toxicity was exhibited by the compound.