Comparative Titrations of Antimeningococcus Sera Produced with Living Cells and with Broth Filtrates

[摘要] In an attempt to demonstrate differences that might be present in antibacterial and antitoxic sera, horses were immunized over a period of months with toxic filtrates of broth cultures or with toxic filtrates and living cells. The sera thus produced were tested by various laboratory methods in comparison with standard therapeutic sera produced by the immunization of horses with living cells injected intravenously, and with meningococcus antitoxin prepared elsewhere.None of the different methods employed, including intracutaneous tests on persons, could be considered satisfactory as a means of titrating antitoxic potency. The lack of a practical and dependable method of standardization of the antitoxic serum was apparent.Nevertheless, it was possible to draw certain definite conclusions from the sum of the trends in the various tests of antitoxic potency: 1. a. Qualitative differences between the antitoxic and the antibacterial sera were not evident by the methods employed.2. b. Marked antitoxic potency was not demonstrable in either type of serum.3. c. The slight or moderate neutralizing activity which was indicated in the sera in one or another of the tests, was usually but not always more pronounced in the antitoxic as compared with the antibacterial serum. No striking quantitative difference between the samples of antitoxin and the standard therapeutic material could, however, be said to obtain.Definite quantitative differences in the agglutinative and precipitative activities of the sera and in their protective action for mice against virulent living cultures were established. The standard sera were much the more potent in these respects.Separation and titration of the water-soluble and water-insoluble globulin fractions of the sera produced with toxic filtrates and with living cells or cells and filtrate indicated a different distribution of the active substance in the sera. The significance of this is not clear, especially since concentration failed to enhance markedly the antitoxic potency.The data accumulated from this investigation do not warrant the substitution of toxic filtrates for the living cultures now used for the production of therapeutic serum.

[学科分类] 生物科学（综合）