Comparative Studies on Toxins of Pasteurella pestis and Pasteurella pseudotuberculosis

Abstract

1. Mice and rats were highly susceptible to the toxin of P. pestis and of P. pseudotuberculosis; rabbits and guinea pigs were refractory to the plague toxin but succumbed to the toxin of P. pseudotuberculosis. 2. Plague toxin caused hemoconcentration and a gradual fall of the blood pressure in rats. These changes are not demonstrable after administration of pseudotuberculosis toxin. 3. The pseudotuberculosis toxin could be neutralized by its antitoxic serum in vivo and in vitro in multiple proportions, thus showing it to be a true exotoxin, whereas the plague toxin could be neutralized only to a negligible extent. 4. No cross immunity to these 2 toxins was evident.