Mechanism of non-specific resistance to the infection with Salmonella enteritidis induced by infection with BCG was studied in CF1 mice and the results obtained are as follows. 1) Clearance foctor to Salmonella enteritidis was not found in the sera from mice vrccinated with BCG. 2) Non-specific resistance could not be transferred to normal mice by injecting with spleen cells and peritoneal cells collected from BCG-infected mice. 3) The non-specific resistance was not reduced by injection of synthetic corticosteroid hormone, “Decadoron”, or by carbon-block, both treaments known to suppress the function of the reticulo-endothelial system. 4) Resistance to Mycobacterium tuberculosis infection could not be induced in mice vaccinated with rough or smooth strain of S. enteritidis.
At the 9th day after BCG-injection, SMA strain mice showed the marked reduction of LD50 for endotoxin from E. coli 0-111 as compared with control mice. On the contrary, the BCG-injected mice showed two to three fold increase of LD50 for the PR 8 strain of influenza A virus. This resistance promoting effect was shared with not only living BCG cells but also heat-killed BCG cells, but not with BCG-filtrate. The effect was most effectively exhibited when BCG was inoculated intravenously, intermediately when intraperitoneally and least when subcutaneously. The inocuation by subcutaneous route was almost ineffective. The effect was exhibited from about the 6th day after BCG-inoculation, reached the peak at the 10th to 12th day, and continued even after 30 days. The effect of BCG inoculation on the intranasal infection of PR 8 was not exhibited. There were no significant differences of LD50, the degree of consolidation and the H. A titre of the lungs of dead mice, between BCG-inoculated and control mice.
Toxic substance was isolated from the French presure cell extract of Pasteurella multocida avian type through ammonium sulfate fractionation, hydrochloric acid precipitation, Sephadex gel filtration, manganese chloride precipitation, calcium phosphate gel chromatography and zone electrophoresis. The substance was shown to be a single component by ultracentrifugation and agar diffusion test. The sedimentation constant in M/15 phosphate puffer (pH 7.0, i=0.16) for the toxin is Sw20=2.99×103. Total nitrogen of this substance was 16.3% ond showed the absorbtion of maximum in 280mμ, while negative in sugar and nucleic acid reaction, thus it was to be protein.
The influence of 5-n-butyl-1-cyclohexyl-2, 4, 6-trioxoperhydropyrimidine (BCP) upon experimental bacterial infection in mice was observed in comparison with that of cortisone. Suspensions of Staph. aureus and K. peneumoniae in varying dilution of an overnight brain heart infusion broth culture were injected intravenously into mice. The drug was administered (SC) simultaneously with the infection as a single dose and four successive doses once daily for 4 days. The survival time of the treated animals and the number of living staphylococci in mice kidney were observed. While cortisone depressed markedly the resistance of animals against the injection as reported previously by other authors, BCP gave no appreciable influences upon the course of infection in mice. This conclusion was based upon the two criteria described; survival time and the viable units of Staph. aurens in mice kidney.
Pasteurella multocida was able to grow in the medium composed of inorganic salts, carbohydrate, amino acid mixture and vitamins. An amino acid essentiol to the growth of all strains used (five strains) was only cystine. Most strains required for their growth glycine, alanine, aspartic acid and phenylalanine. Of vitamins and haematin examined pantothenic acid, biotin and thiamin were effective. In the presence of lactalbumin hydrolysate (enzymatically) pantothenic acid, thiamin, riboflavin and haematin were effective.
Studies were carried out to investigate the sensitivity to 2-Mercaptoethanol (2-ME) of swine hemagglutintion-inhibition antibody against Japanese encephalitis virus (JEV) using swine which were raised at the Zootechnical Experimental Station at Fukuoka. The results obtained are as follows. (1) In the case of natural infection, 2-ME sensitive antibodies were detected during the first 3 or 4 weeks of antibody response; thereafter the antibodies were found to be resistant to 2-ME treatment. (2) Maternal antibodies found in piglet were found to be resistant to 2-ME treatment. As long as the piglet had detectable amount of maternal antibodies, their titers were stationary even when the piglet should have been infected by JEV. (3) Vaccination studies revealed that the antibodies were 2-ME resistant when the swine already had anti-JEV antibody; when they had no detectable antibody, the first antibodies produced after the vaccination were found to be 2-ME sensitivity and they became 2-ME resistant after having the opportunity of natural infection.