[Immunochemical characteristics and serologic properties of lipopolysaccharides isolated from various Brucella...

The results of the comparative analysis of LPS isolated by different methods of extraction from the cultures of several Brucella species differing in their virulence are presented. Purified LPS preparations have been obtained from Brucella virulent and vaccine strains by using such methods as water-phenol extraction, Boivin's method, mild alkaline hydrolysis of the antigen according to Boivin's procedure. The presence of certain relationship between the method used for the extraction of Brucella LPS to be compared and their chemical composition, immunological characteristics and serological activity has been established. As shown in this investigation, in the process of the preparation of a highly sensitive diagnosticum for the passive hemagglutination test the use of LPS obtained from Brucella virulent strains, but not from the vaccine strain, by the method of mild alkaline hydrolysis according to Boivin's procedure is expedient. The data presented in this work indicate that the soluble complex of lipid A obtained from Brucella LPS has been found to possess serological activity. The results of the study of the serological properties of lipid A indicate that the lipid component may also play a certain role in the manifestation of the serological activity of Brucella LPS.