The Endotoxin of Pasteurella pseudotuberculosis

Abstract

An endotoxin was prepd. by lysis of 2 different strains of P. pseudotuberculosis with bacteriophage; 25 other strains produced no demonstrable, endotoxin. The endotoxin was shown to be a product of bacterial lysis, and not due to toxic action of phage. It produced major circulatory changes and death in less than 12 hrs. in rabbits, guinea pigs, and white mice. In addition to death of expt. animals, the endotoxin in small doses produced necrosis in the skin of guinea pigs- The 2 strains producing the lethal factor were the only 2 strains able to produce the necrotic effect, The endotoxin was inactivated by heating for 30 min. at 60 C, being slightly more sensitive in this respect than the endotoxin of P. pestis. The endotoxin, after detoxification with formalin was ineffective in producing entitoxin, no evidence of protection being obtained. Except for its sensitivity to heat and chemicals, the endotoxin has most of the properties of other bacterial endotoxin.