[Classification of precipitates formed by meningococcal group antigens during counterimmunoelectrophoresis]

In counter immunoelectrophoresis (CIE) of group meningococcal polysaccharides and meningococcal diagnostic group-specific antisera the manifestation of precipitate formation depended on the concentration of the antigen: with the increase of the group polysaccharide concentration the reaction became less pronounced up to complete disappearance of the precipitate, which could be the cause of pseudonegative reaction. Precipitates formed in the CIE of group polysaccharides differed in their form and appearance. To evaluate the CIE results, the classification of the precipitates has been proposed by dividing them into 3 categories differing in their appearance. The category of the precipitate indicates the specificity of the reaction. CIE has allowed one to reveal the immunological heterogeneity of meningococcal group polysaccharides.

Detection of Pneumococcal Capsular polysaccharide antigens by latex agglutination, counterimmunoelectrophoresis, and radioimmunoassay in middle ear exudates in acute otitis media

The presence of pneumococcal antigen in middle ear exudates during acute otitis media was studied by latex agglutination and counterimmunoelectrophoresis. The positive antigen findings were confirmed by radioimmunoassay. Latex agglutination gave a positive result in 63% and counterimmunoelectrophoresis in 76% of samples that grew Streptococcus pneumoniae. The methods were complementary; the antigen was detected by one or both of the methods in 88% of these samples. Pneumococcal antigen was further detected in 15% of samples that grew other otitis pathogens and in 33% of samples in which no pathogenic bacteria were recovered by culture. The distribution of pneumococcal serotypes found by immunochemical methods only corresponded to that found by culture.

Immunological studies on dermatophytes. IV. Chemical structures and serological reactivities of polysaccharides from Microsporum praecox, Trichophyton ferrugineum, Trichophyton sabouraudii, and Trichophyton tonsurans

The chemical structures and serological specificities of polysaccharides isolated from four species of dermatophytes, Microsporum praecox, Trichophyton ferrugineum, T. sabouraudii, and T. tonsurans, were investigated. Each of these species yielded a mixture of crude polysaccharides which could be separated into three water-soluble, neutral polysaccharides free of nitrogen. These were grouped as galactomannan I, galactomannan II, and glucan. The galactomannans I were quite similar in chemical structure. When measured by complement fixation, their serological cross-reactivities were similar with rabbit antisera to each of these species except T. sabouraudii. The differences in their relative reactivities with this antiserum could be correlated with differences in structure and specificity of this antiserum for galactofuranose end groups. The galactomannans II differed both in chemical structure and in their serological reactivities with antisera to each of these species. The galactomannan II from T. ferrugineum differed most in chemical structure and was the least reactive serologically. The glucans also differed in both structure and serological reactivities.