Toxicity of Pasteurella tularensis Killed by Ionizing Radiation

Toxicity of Pasteurella tularensis killed by ionizing radiation.

Approximately 2 x 10(11) viable Pasteurella tularensis cells per ml, contained in suspensions, were killed by exposure to 10(6) r of gamma-radiation. When injected intraperitoneally into mice, the irradiated suspensions initially contained about 10 ld(50) per ml, and immunized mice against challenge with fully virulent strains of P. tularensis. Toxicity and immunizing activity of the suspension...

Pathological changes in rabbits injected with Pasteurella tularensis killed by ionizing radiation.

Suspensions of Pasteurella tularenais killed by exposure to ionizing radiation were toxic for rabbits. A dose of 3 ml or more of a suspension containing 2 x 1011 to 3 x 1011 organisms per ml was lethal within 24 hours of a single intravenous injection. The r lor pathologic changes were extensive hemorrhagic necrosti of the spleen, focal coagulation necrosis of the liver, pneumoiitis, and glomer...

Antigenicity of psittacosis vaccines killed by ionizing radiation.

Succinoxidase system of Pasteurella tularensis.

Preparation of washed particles. Cell-free extracts of highly virulent P. tularensis strain Sm were prepared by sonic disintegration of cells as described by Rendina and AMills (1957). Twenty ml of undialyzed centrifuged (3000 x G for 30 min) sonic extract, containing 3.8 to 4.2 mg SN per ml, were centrifuged for 3 hr at 105,000 X G at 5 C. The supernatant was decanted and thc reddish precipita...

Immunization of Mice with Irradiated Pasteurella Tularensis.

Viable attenuated tularemia vaccines have been shown to bt. effective in immunizing mice and other animals against challenge with high].y virulent Pasteurella tularensis. Nonviable preparations, however, induced little or no resistance to challenge with even small numbers of virulent organisms. It seemed reasonable to expect that antigenicity would be retained to a greater extent if the organis...