Characterization of an immunogenic fraction of Pasteurella multocida culture filtrates

An immunogenic fraction (IF) of Pasteurella multocida strain P-1059 was separated from culture filtrate by Sephadex gel filtration. Additional fractionation of IF with aqueous ether resulted in the glycoprotein-like preparation (GLP) while extraction with aqueous phenol provided the lipopolysaccharide-like preparation (LPP). The unextracted IF contained carbohydrate, protein, and lipid; the GLP contained carbohydrate and protein; and the LPP contained carbohydrate and lipid. The GLP was maximally protective for mice against homologous challenge, and was medially toxic in rabbit skin when compared to the other culture-filtrate preparations; the LPP was maximally toxic in rabbit skin, and was least protective for mice; and the unextracted IF was medially protective for mice, and was least toxic in rabbit skin.

[Chemical composition of surface antigens in the pseudotubercular microbe]

Superficially-active complexes, having a toxic effect and promoting generalization of the infestation process in the animal organism have been isolated from the pseudotubercular microbe. The chemical composition of these biopolymers has been studied.

[Pathogenicity of K. ozaenae for mice and chick embryos]

The authors tested the virulence of K. ozaenae--its old museum strains, the freshly isolated ones and those passaged on meat-peptone agar; experiments were carried out on mice and chick embryos. To mice the culture was administered intraperitoneally, subcutaneously, intranasally, and to embryos--into the allantoic cavity and on the chorioallantoic membrane. Irrespective of the method of administration, the freshly isolated strains were highly virulent both for mice and for chick embryos. The virulence of such strains decreased in the process of passaging on the nutrient medium. Old museum strains were of low virulence for albino mice and avirulent for chick embryos. In comparing the virulent and avirulent strains there were found no differences in the antigenic structure and toxicity of the Boiven complex, cytoplasm, membrane, capsular polysaccharide or whole virulent and avirulent bacteria killed by heating.

[Biological and immunochemical properties of a complex of soluble antigens from N. meningitidis, serogroups A, B and C]

Complexes of surface soluble antigens were obtained in grown meningococci of serological groups A, B and C in fluid nutrient media. In studying the chemical composition and biological properties of these complexes released of the nutrient medium components it was revealed that they consisted of proteins, carbohydrates and lipids, possessed marked group-specific properties in the PHAT, were toxic (LD50 about 0.15 mg) and immunogenic.

Isolation of a protective, non-toxic capsular antigen from Pasteurella multocida, types B and E

Separation of the capsular antigen and endotoxin from saline extracts of Pasteurella multocida type B was achieved by fractional precipitation from aqueous solution by addition of polar organic solvents. Biological tests for the presence of endotoxin showed that it was absent from capsular antigen preparations so obtained. Properties of the capsular antigen suggested that it was a high molecular weight acidic polysaccharide. The solvent fractionation method was found to be equally applicable to separation of capsular antigen and endotoxin of P multocida type E. The type B capsular antigen in the presence of aluminium hydroxide gel adjuvant, was poorly immunogenic in rabbits. In cattle, however, a dose-dependent serological response was obtained as demonstrated by the mouse passive protection test.

[Comparative characteristics of the toxic properties of the whooping cough microbes]

The author presents materials concerning the study of the toxic properties of 12 pertussis cultures used in the USSR for the production of vaccines. As a result of studying the toxic properties of the microbes in the test of the change of the weight of mice, and in experiments of testing the anaphylactogenic and histamine-sensitizing activities it was revealed that the strains of pertussis microbes differed by the quantitative content in them of the thermolabile toxin, endotoxin, lymphocytosis-stimulating and histamine-sensitizing factors; therefore, the period of keeping the pertussis suspensions for 1.5 months from the moment of detoxication proved to be inadequate for some of the strains. Since the toxic properties of the strains failed to correlate with their protective activity, in recommendation of pertussis strains for the production of pertussis vaccine preference should be given to the strains with lesser toxic properties.

[Immunochemical study of the antigenic structure of bacteria of genus Bordetella. IV. Fractionation of B. pertussis extracts and study of the immunochemical and biological properties of the isolated fractions]

Fractionation of an extract of pertussis microbes was carried out with the aid of gel-filtration on Sephadex G-100, ion-exchange chromatography on DEAE-cellulose, and preparative electrophoresis. Fractions differing in serological, immunogenic activity and the content of antigenic components were isolated. In using the method of gel-filtration of sefadex G-100 the greatest serological, immunogenic and histamine-sensitizing activity was possessed by the high-molecular fraction containing 8 of 11 antigenic components detected in the initial extract. The antigenic components were distributed into 5 fractions by the ion exchange chromatography on DEAE-cellulose. The greatest serological activity was possessed by fractions exiting from the column at the 0.01--0.04M interval of the phosphate buffer concentration. A method of preparative electrophoresis from the pertussis microbes extract was applied and two fractions were isolated from the anode and the cathode zones, each containing 4 antigenic components only, but possessing serological and immunogenic activity and having no histamine-sensitizing properties.

[Development of new types of chemical vaccine for prevention of intestinal infections and problems of their qualitative evaluation. III. Comparative study of immunologic characteristics of experimental antigenic preparations]

As a result of comparative study of the immunological properties and antigenic activity of thyphoid, paratyphoid A and B and Sonne and Flexner dysentery antigenic preparations obtained by various methods there was revealed a decreased toxicity of the experimental preparations of the Tashkent and Leningrad Institute of Vaccines and Sera (in comparison with the tryptic antigens) and a considerable advantages of the experimental thyphoid and paratyphoid antigenic preparations by their capacity to induce the H-antibody formation in the presence of the O-antigenic activity. The preparations of the Moscow Institute of Vaccines and Sera had increased toxicity. The detected advantages of the experimental antigenic preparations of the Tashkent and Leningrad Institute of Vaccines and Sera permitted to recommend the method used in their making to obtain new chemical vaccines against the intestinal infections.

[Study of the role of type-specific antigen in the process of Shigella flexneri interaction with epithelial cell and macrophage cultures]

Epithelial cells of the HEp-2 line infected in parallel by genetically connected strains of Sh. flexneri, differing in the capacity to synthesize the type antigen were studied morphologically. The type antigen proved to show no significant influence on the penetration of dysentery bacilli into the cell. A study of the process of phagocytosis of the mentioned strains by a culture of peritoneal macrophages of guinea pig demonstrated that the presence of a type antigen communicated to the bacteria some selective advantages within the macrophages increasing their resistance to the action of the digestive enzymes.

Preliminary observations on the protective action of a cytoplasmic immunogen of Neisseria gonorrhoeae

A non-toxic protein, termed beta(-t), consisting of lysine, aspartic acid, threonine, serine, glutamic acid, glycine, and alanine (1.2:1.3:1.3:3:2.2:7:1) was isolated, by the polyacrylamide gel electrophoresis, from an isoelectric toxic proteinaceous fraction beta(+1) of the type 1 cytoplasm of N. gonorrhoeae. The beta(-t) antigen elicited delayed hypersensitivity and vigorous primary and secondary humoral responses in rabbits, and it conferred immune protection against intraocular gonococcal infections.

Vi antigen from Salmonella typhosa and immunity against typhoid fever. I. Isolation and immunologic properties in animals

The role of Vi antigen in human immunity against typhoid fever has been debated for decades. Circumstantial evidence indicates that Vi antigen may play a role in pathogenicity and immunity. A Vi preparation was isolated from Salmonella typhosa, the causative organism in human typhoid fever, by a mild precipitation method. It was significantly more potent in animal studies than preparations from Citrobacter used in the past for human study and less toxic than conventional typhoid vaccines. With this antigen, the role of Vi antigen in human protection is now being investigated.