BIOLOGICAL ACTIVITIES IN EXTRACTS OF PASTEURELLA PESTIS AND THEIR RELATION TO THE "PH 6 ANTIGEN".

Bichowsky-Slomnicki, Leah (The Weizmann Institute of Science, Rehovoth, Israel) and Shlomo Ben-Efraim. Biological activities in extracts of Pasteurella pestis and their relation to the "pH 6 antigen." J. Bacteriol. 86:101-111. 1963.-Three kinds of biological activities could be found in crude extracts prepared from all the tested strains of Pasteurella pestis: cytotoxicity for monocytes, ability to agglutinate red blood cells, and induction of primary inflammatory reactions of the skin. All these biological activities were related to the presence of the "pH 6 antigen." In addition, fractions of the pH 6 antigen devoid of agglutinating activity against red blood cells, but possessing the other biological activities, could be isolated. The active biological principles appear to be protein in nature. The possible role of the described biological activities in the pathogenesis of plague is discussed.