THE RELATIONSHIP BETWEEN THE PLAGUE BACILLUS AND THE PHAGOCYTIC DEFENSE SYSTEM OF THE HOST
ARMY BIOLOGICAL LABS FREDERICK MD
Pagination or Media Count:
The hypothesis that the ability of Pasteurella pestis to resist phagocytosis is the major determinant of its virulence has been re-evaluated in the light of recent evidence. Lethality titrations of virulent phagocytosis-susceptible plague bacilli were carried out in guinea pigs under the following conditions 1 the organisms were injected intraperitoneally into untreated animals 2 the organisms were injected intraperitoneally into animals that had been pretreated 24 hours earlier with 7.6 per cent sodium caseinate solution in order to mobilize massive number of phagocytes in the peritoneal cavity 3 organisms contained within phagocytes from mice were injected into the peritoneal cavity of untreated animals 4 the organisms were introduced directly into the circulatory system of untreated animals in order to expose the bacilli to rapid ingestion by reticuloendothelial phagocytes. All of these titrations revealed that the defense systems of the experimental animals were ineffective against plague.