The structure and immunochemical specificity of 0-antigens of 03 serogroup Pseudomonas aeruginosa.

Using the method of phenol-aqueous extraction, lipopolysaccharides (LPS) were isolated from 5 strains (subgroups) belonging to 03 serogroup of P. aeruginosa (4). Specific polysaccharides were isolated from the LPS by means of acid hydrolysis. It has been established that the polysaccharides determining O-antigenic specificity have a uniform structure. They consist of repeated trisaccharide links comprising: 2,3(1-acetyl-2-methyl-2-imidazolino-5,4)-2,3-dideoxy-D-mannuronic acid (Im) 2,3-diacetamido-2,3-dideoxy uronic acid with -D-manno-(M) or -L-gulo-(G) configuration and 2-acetamido-2-deoxy-D-fucose (F) with alpha or beta configuration of the glycosidic bond. The structure of 0/3a/3d, 3f polysaccharide has not been definitely cleared up. Serological analysis using passive haemagglutination reaction (PHAR) testifies to the presence of antigenic cross activity of all the five LPS. Antigenic specificity of LPS of the individual subgroups was revealed in passive haemagglutination inhibition reaction (PHAIR). Partial cross activity was clearly demonstrated in immunoprecipitation experiments in the five subgroups. Serological properties of the LPS of P. aeruginosa 03 subgroup essentially correlate with the structure of their polysaccharide chains determining O-antigenic specificity.