ON A SOLUBLE TOXIN PRODUCED BY BACILLUS CHAUVOEI

Abstract

The production of a soluble toxin by Bacillus chauvoei had been demonstrated by Kitt, Leclainche-Vallée, and others. According to Leclainche-Vallée the culture of this organism in Martin broth is far more virulent than that in common broth. They used rabbits for the demonstration of the toxin produced by this organism, and gave them 1c.c. of the toxin intravenously, which caused death within twenty-four hours after the injection.
After years of strenuous studies the author succeeded at last in demonstrating the production of a soluble toxin by Bacillus chauvoei. For this purpose he used a broth added with 10-20 per cent. fresh blood¹ as recommended by Kitt for the cultivation of the organism. The aerobic culture of the organism in this medium was highly virulent and fatal for guinea-pigs in doses of 0, 0025c.c., when used subcutaneouly; it caused sometimes fatal infection in rabbits.
The filtrate of the culture caused death of guinea-pigs in doses of 0, 5c.c. when given intravenously, while 3-5c.c. was required to kill the animals by subcutaneus injection. The addition of 0, 5 per cent. anhydrous sodium sulfite to the bloodbroth favored the production of the toxin and 0, 1c.c. of the filtrate was sufficient to cause death in guinea-pigs.
The toxin production in the blood-broth reached its height in from two to four days when incubated at 37°C., from that time on the cultures gradually lose their toxicity and the sevenday culture was usually not so potent as to cause death in guinea-pigs.
When guinea-pigs were intravenously injected with the toxin they showed dyspnoea, roaring, cough, sneezing and hemoptysis, and died under state of suffocation within twenty-four hours. Sometimes these symptoms persisted, death of the animals occurring in from two to seven days. The characteristic changes found at autpsy were hemorrhages in subcutis, muscles and lungs, and on serous membranes and gastro-intestinal mucous membranes, as well as bloody-serous transudate in pleural and peritoneal cavities, the changes quite similar to those found in the animals infected with natural or cultural virus.
A majority of the animals which survived the intravenous injection of the toxin proved to be immune against subcutaneous inoculation of a cultural virus carried out one to three weeks later, although in this case the immunity produced was less strong than in the case of subcutaneous injection of the toxin.
The mouse was immune against the toxin; in rabbits, even when given 5-10c.c. intravenously, there were no remarkable symptoms of intoxication, although a temporary rise of temperature and slight inactiveness were observable. Thus in the rabbit the author was unable to obtain the same results as reported by the French investigators.