Isolation of the protective brucella antigen from the virulent strain and comparison of its properties with the antigen isolated from the vaccine strain

Currently, extensive work is being carried out related to the isola-tion of various antigens from brucella and increasing their protective activity. Such work has been carried out for quite a long time, but so far no anti-brucellosis vac-cine obtained by this method has been offered in practice. In this regard, the search for new approaches to the isolation of brucellosis antigen and the creation of a vac-cine preparation based on the conjugation of the antigen with a high-molecular car-rier-an immunostimulator is quite relevant. In our studies, we worked out the pro-cess of isolating a protective antigen from virulent strains (B. abortus 544, B. abor-tus 54, B. melitensis 16M). When using the liquid method of brucella cultivation in a liquid medium in the presence of the above components, it was possible to in-crease the antigen yield from virulent strains by 30%. It was found that during the cultivation process, no more than 1% of the cells in the R-form appeared in the B. abortus 54 strain, while in others this indicator ranged from 3 to 15%. Thus, the strain B. abortus 54 was chosen as an antigen producer, as it had more stable cul-tural properties. The method of obtaining a protective antigen from virulent brucel-la strains has been optimized. It was found that the strain B. abortus 54 has stable cultural properties and stable production of protective antigen, which allows it to be used as an antigen producer. The physicochemical properties of the obtained anti-gen were determined. In its properties, the antigen from the virulent strain differs from the antigen isolated from the vaccine strain that was previously used. The iso-lated antigen has more pronounced protective properties, its yield per unit of bakmass is much higher, which allows it to be used to obtain a specific part of the conjugated antigen-polymer vaccine.