For a long time swine erysipelas has been prevalent in some pig-raising districts of Japan where it checked the progress of pig industry. In these districts, therefore, both serum-alone method and simultaneous method with serum and culture have been employed since many years, the latter causing sometimes severe reactions, even losses, among noble breeds of the animal, owing to the use of culture. Under these circumstances, an attempt was made to prepare a safe and effective vaccine by treating the growth of organism of swine erysipelas with iodine, and very satisfactory results were obtained.
1. Preparation of the vaccine. The growth of 24-48 hour agar cultures of the organism was suspended in saline solution and mixed with broth cultures; the suspension was then placed in a bottle and added with Lugol's solution (iodine, 1 part; potassium iodide, 2 parts; distilled water, 200 parts) in the proportion of 1:5 and allowed to stand at the room temperature for one hour, during which time the mixture was Shaken several times. The suspension thus treated is uniformly clouded and yellowish in clour, but after standing for some time the supernatant liquid becoming transparent owing to the precipitation of iodized protein.
2. Immunizing action of the iodized vaccine. To demonstrate whether the iodized vaccine, prepared as above-mentioned, confers solid immunity to the animals treated, it was inoculated into mice, pigeons, rabbits, and pigs. Single intraperitoneal injection of 0.3-0.4c.c. protected mice against control inoculation with 1, 000-10, 000 times lethal dose of the organism. Pigeons receiving double subcutaneous injections, in doses of 2c.c. and 4c.c., resisted the control injection of 100-10, 000 times lethal dose of the organism. Rabbits inoculated twice subcutaneously or intraperitoenally with doses of 5c.c. and 10c.c. ten days apart proved immune against the intravenous injection of 0.2c.c. of a virulent broth culture (4 times lethal dose).
As the results of the immunizing experiments with small laboratory animals were satisfactory, the vaccine was inoculated into 8 pigs, out of which one half received subcutaneously a dose of 5c.c. and another half two doses; fifteen days later the vaccinated animals, with two control animals (pigs), were injected with a dose of 10c.c. of 48 hour serum-broth culture: the half receiving double inoculations and two out of another half treated only once showed no reaction at all, and remaining two of the latter slight rise in the temperature (44.5°C) and a few red patches, while the control animals showed elevated temperature reaching 41°-42°C., lessened appetite, dullness and characteristic skin lesions followed by crust formation, with recovery.
3. Development of agglutinine in the vaccinated. animals Agglutination test was carried out with blood serum obtained from the above-mentioned animals before and after vaccinations, and appreciable production of agglutinine was demonstrated after the treatment, the titer of the serum being 1:160-1:5, 120, while that of the normal serum being below 1:80, rarely 1:180.
4. Results of practical use of the vaccine. In a district where swine erysipelas has been prevalent, the vaccine was practically used; at first 75 pigs were inoculated in the proportion of 1c.c. to every 10 kilograms of the body weight of the animal, with no local or general reactions. During last year the number of animals treated with the vaccine amounted to 1, 693 in all, with very satisfactory results, which lead practically all pig-raisers there to prefer this vaccine to simultaneous inoculation of serum and culture. How long will last the immunity conferred to the animals by this method of vaccination is not yet determined at the present time.
The. vaccine, when properly kept, retained its potency for about one month.

View full abstract

In an earlier report (see this journal Vol. I, No. 1) the writer referred to the results of his experiments carried out to investigate the nature of lumbar paralysis occurring among the noble races of goat imported here from Switzerland and their offsprings, and arrived at the conclusion that this disease is an infectious disease anatomically characterized by meningitis spinalis and sclerosis spinalis, its causal organism being a streptococcus.
In the present paper details are given of further experiments on this disease. The lesions observed by him consist chiefly of infarnmation of the spinal cord, namely-leptomeningitis serosa et lymphocytica and myelitis circumscripta ventralis with myelomalacia periarterialis in the white matter in earlier stages, while in chronic cases leptomeningitis fibroplastica and gliosis sclerotica spinalis with periarteriitis fibrosa are found. He demonstrated often in the brain leptomeningitis basilaris serosa et lymphocytica, and encephalitis lymphocytica or encephalomalacia perlarterlalrs in the white matter near the ventricles.
The streptococcus mentioned in the previous paper was isolated from the cerebro-spinal fluid in all twenty-four cases bacteriologically examined. The organism is a coccus about 0.6-0.8μ in diameter, occurring in pairs or in short chains, Gram-positive, and does not grow well on the artificial media; gelatin is not liquefied, milk not coagulated, and no indol produced. The organism causes hemolysis when grown on blood agar plates, tiny colonies being surrounded by clear zones. The following carbohydrates are fermented: arabinose, dextrin, galactose, glucose, glycerin, inulin, lactose, levulose, maltose, mannite, mannose, raffinose, rhamnose, saccharose, salicin, soluble starch, and sorbite.
Twenty healthy goats inoculated intraspinally with cultures of this organism showed symptoms, and anatomical and histological changes similar to those of the natural cases, especially so when the resistance of animals is lessened before the inoculation by bleeding, administration of cresin, or intravenous injection of the serum obtained by immunizing the rabbit with central nervous system of the goat.
Results of experiments regarding the reactions of immunity, such as agglutination, precipitation, and complement-fixation, were also satisfactory.
In conclusion, the writer emphasizes the streptoccus to be the causal organism of this disease from a bacteriological and immunological point of view, giving to this organism the name Streptococcus caprinus, owing to some differences existing between this and other pathogenic streptococci.

View full abstract