[Immunochemical study of the meningococcal cell wall].

Meningococcus strains--standard and those isolated from the cerebrospinal fluid of patients suffering from the cerebrospinal meningitis were grown on fluid and solid protein-free nutrient media. Electron microscopic study showed that in the strains isolated from patients the wall was much thicker than in the standard strains. The cell wall preparations were obtained by its solution at pH 9.0 and separation from the microbial residue. In the cultures grown on the solid medium the cell was dissolved already in its washing at pH 7.2. It was revealed in gel filtration that the cell wall preparations consisted of three fractions. The fraction with the mol wt of from 2 to 3 million possessed a complex protein-polysaccharide nature, contained all the antigens of the group and intergroup specificity, was nontoxic for mice and antigenic for rabbits. Two other fractions whose mol wt was below 67000 contained no antigens.