[Hemolytic and lethal properties of Ps. aeruginosa exotoxin]

Hemolytic and lethal properties of tbe preparations of exotoxin obtained from three Ps. aeruginosa strains in cultivation of bacteria on a hard medium covered with cellophane were studied. The exotoxin possessed a high hemolytic activity and after intraperitoneal administration caused the death of mice in the course of 24 hours. A marked thermostability and a wide range of temperature conditions and of the pH of the medium for expression of the hemolytic activity of the exotoxin was noted. Four fractions (one of which--the protein one, rapidly moving in the direction of the anode possessed hemolytic activity) were revealed by paper electrophoresis. Lethal activity failed to correlate with the hemolysin titre. At the same time the lethal factor, as in the case of hemolysin, was precipitated by trichloracetic acid and practically failed to be precipitated by chloroform; thermal treatment (70 degrees C for 30 min and 100 degrees C for 60 min) of the exotoxin failed to eliminate its toxicity; however, it somewhat delayed the periods of death of the animals.