STUDIES ON PLAGUE II. Pasteurella pestis Toxin

Abstract

The inoculation of rabbits with purified Pasteurella pestis toxin combined with an adjuvant resulted in the production of a potent antitoxin. Serologically, the toxin appears to be free of contaminating envelope antigen since it does not react with anti-envelope sera and the specific antitoxin fails to react with purified envelope substance. The antitoxin neutralizes toxins extracted from a number of virulent and avirulent strains of the plague bacillus. Similarly heterologous plague antisera react with the purified toxin. Purified toxin sensitizes tannic acid-treated erythrocytes, and this provides a useful procedure for determining serum antitoxin levels. Using the specific antitoxin in a complement-fixation test, it is possible to measure the concentration of toxin antigen in cultures, toxoids, etc.