Antibody Responses of Monkeys and Rabbits to Streptokinase and Staphylokinase.

In our previous experiments, because of the weakness of antigenicity of streptokinase (STK) and staphylokinase (SAK), the antibody response of rabbits and dogs to these extracellular bacterial substances could not be demonstrated by the measurement of antibody titers in the sera of the immunized animals, although the antibody response of humans to STK was proved by demonstrating the rise of anti-STK titers in the sera of human volunteers treated therapeutically with a commercial STK-preparation (Varidase-Lederle). In our present experiments, however, the antigenicity of these substances was clearly demonstrated by the used of monkeys as the experimental animals, in substitution for rabbits, or by the improvement of the immunizing method in rabbits. In the experiments with monkeys anti-STK and anti-SAK were readily produced in the sera of the immunized animals by the primary injections of STK and SAK respectively without adjuvant. In the case of a primary immunization of rabbits, however, the addition of complete Freund\u27s adjuvant to STK or SAK was necessary for the production of anti-STK or anti-SAK in the sera of the immunized animals. Considerablly high titers of anti-STK or anti-SAK were detected in the sera of rabbits, receiving a booster injection after a long lapse of time following the primary injection of the same antigens. The difference between the antibody response of monkeys and that of rabbits to STK and SAK was discussed in connection with natural infection of streptococci and staphylococci among these animal species

Immunization of Mice against Infection with Salmonella blegdam : Especially Protection of Mice from Typhoid Infection by Immunization with Living Rough Variants of Salmonella

It is generally known that immunization with killed bacilli has a protective effect on bacterienda. 11 But typhoid fever, paratyphoid fever and anthrax, which are also accompanied with bacierienda, have been considered to be exceptional cases. For anthrax effective immunity could not be introduced with killed vaccine, though Louis Pasteur1) invented a preventive inoculation method hi 1881, until recently low virulent living organism inoculations have been considered to be the only effectivemethod, as far as anthrax is concerned. Recently Cromartie, Watson, Bloom and others2) have proved why immunization with living bacilli is the only preventive measure for anthrax. Based on their findings, it is now possible to provide protection with vaccines containing no living organisms. Thus one of the exceptional cases has been removed, leaving mechanism of immunity of typhoid diseases as the remaining problem. In typhoid and paratyphoid fever, it is statistically known that preventive inoculation with killed bacilli has lowered morbidity and lethality. But the immunity resulting from this vaccination is not as strong and effective as in immunity after recovery Moreover its effectiveness is not completely supported, either experimentally or theoretically. This Subject has been studied at a high level in our country, particular), by Kobayashi and his collabora- tors3). According to their opinion, the protective power against typhoid and paratyphoid. infectioncan be established by vaccination with living bacilli, whether in smooth or in rough type, but not with killed vaccine. However, Hazato and his collaborators4) have reported that intravenous injectionsof killed bacilli have given satisfactory protection to mice against the infection of Salmonella enteritidis I , equal to those of living bacilli. Hosoya and others5) have recently stated that immunization with theirso-called T.T.T. or T.A.T. vaccine, which contains no living bacilli, has protective effect on infectionof Salmonella enteritidis of mice and Salmonella abortus equi of guinea-pigs. Ominaga6) has denied