[Immunochemical studies of antigen K 88 from E. coli strains isolated from pigs]. / Imunokhimichni prouchvaniia na antigen K 88 ot shtamove E. coli, izolirani ot praseta.

Experiments were carried out to isolate, purify, and concentrate the K 88 antigen of Escherichia coli organisms. Employed were two purification methods --isoelectric precipitation, and immunoadsorption. The content of protein and carbohydrates was determined. The amino acid analysis revealed that the antigen contained 17 amino acids, mostly represented being asparagic acid, glutamic acid, and alanine. It was found that antigen K 88 obtained by the two methods was purified up to the state of homogeneity: in electrophoresis a band strip was produced, and in immunodiffusion and immunoelectrophoresis the antigen produced a precipitation arc against the homologous complete antiserum. In the elimination of K 88 in DEAE-Sefadex A-50 one peak only was present. The purified K 88 antigen was shown to possess good immunogenic properties. Sera obtained after hyperimmunization were with titres ranging from 1:640 to 1:1280, and they produced agglutination only with strains containing antigen K 88.

[Adsorption of antigens K88 and K99 on aluminum hydroxide gel]. / Adsorbtsiia na antigeni K 88 i K 99 vurkhu aluminiev khidrookis-gel.

Studied was the effect of the pH value of the medium, of the concentration of the antigen and the adsorbent on the adsorption of K 88 and K 99 on aluminium hydroxide-gel. Use was made of strains O 45:K 88 and O 14:K 99. The optimal parameters of pH and the concentration of aluminium oxide as well as of aluminium hydroxide-gel as an adjuvant, substantiating the maximum adsorption capacity of the latter with regard to the two Escherichia coli antigens used. Established was the maximum amount of the antigens which could be adsorbed by as much as 1 cm3 of aluminium hydroxide-gel. According to the authors such amount could serve to indicate the way how to produce effective preparations to be deposited with the two-antigen adjuvant.