Mycobacterium tuberculosis, the causative organism of tuberculosis is responsible for approximately three million death cases annually and the mortality rate of infections caused by multiple drug-resistant strains of this bacterium exceed 80%. M. tuberculosis is coated by a number of polysaccharides of unusual structure. A unique component termed polysaccharide II is composed of alpha, 1,2-linked B-glucose residues. Schemes were designed to isolate this polysaccharide from extracts of M. tuberculosis. We demonstrated that the major monosaccharide components in soluble polysaccharide fractions from Mycobacteria are arabinose, mannose and galactose. A polysaccharide fraction was also identified which contains mannose and glucose in approximately equal amounts. We demonstrated the presence of a glycogen-like polysaccharide as one of the extracellular polysaccharides of Mycobacteria and developed a method for the chemical synthesis of oligosaccharides corresponding to the putative polysaccharide II.
