実験的ブ菌感染症の研究

Abstract

Previously it was reported that the mice infected with a sublethal and kidney abscess forming dose of St. aureus No.248 βH strain could have a strong and stable resistance to the two weeks later superinfection with the homologous staphylococcal strain. This experimental evidence would provide much advances in the experimental approach to the analysis of the staphylococcal infection and its immunity. However in this experiment it must be considered that the very large dose of bacterial cells injected intravenously for the preinfection could have induced the so-called non-specific resistance though the RES organs of the infected mice.The present auther carried out the experiments analyse the possibility of the nonspecificity in the resistance of the infected mice above mentioned. The intraperitoneal route was employed for the pretreatment of the mice in order to avoid the kidney abscess formation, because Kondo et al ascribed one of the most efficient factors providing the resistance to the infected mice to the formation of the kidney abscess and its liberation of somewhat unknown immunological agents.Experimental results are as follows:1) The mice pretreated with living vaccine of St. 248 βH through the intraperitoneal route could show an extremely increased resistance to the 48 hours later superinfection with the same staphylococcal strain of lethal dose injected intravenously as well as intraperitoneally.2) The mice pretreated with the chrome killed vaccine of the staphylococcal strain No.248 βH could also resist to the super infection with the same strain, though it took 10 times as much dose of this killed vaccine to give the same efficient effect as the one of the living vaccine.3) Similar resistance inducing effects were shown by the pretreatment with the chrome killed vaccine of various other staphylococcal strains different from St. 248 βH strain.4) The results of the analytical experiments on the specificity of this early arising resistance showed that it was nonspecific at least in the relationship between the two strains employed for the pretreatment and the superinfection.5) Therfore, the resistance inducing factor can be considered to be contained in the staphylococcal cells and fixed in their chrome killed vaccine. The content of this factor seems to be different in various staphylococcal strains and and at least different from the coagulase factor.