Modeling of Radiation Damage on the Background of Pasteurellosis Infection of the Organism

Purpose: Simulate radiation-pasteurellosis lesions in the body.

Material and methods: Modeling of radiation and pasteurellosis lesions caused by the action of physical and biological factors on the organism Modeling of acute radiation disease (ARD) of animals was carried out by gamma-irradiation at the “Puma” facility with an exposure dose rate of 2.36×10^-5 A/kg. Pasteurella multocida, the causative agent of pasteurellosis, as one of the most frequently occurring pathogenic agents, was used as a model biological agent to reproduce the experimental biological lesion. Modeling of radiation-pasteurellosis lesion was carried out on rabbits and on white mice with live weight of 2.8‒3.4 kg and 18‒20 g, respectively.

Results: In experiments on white mice to determine the optimal doses of the affecting agents it was found that the minimum doses of gamma rays and the causative agent of pasteurellosis are 6.0 Gy and 4.5×10³ microbial cells per kg (m.k./kg), 3.9 Gy and 9.0×10³ m.k./kg, which leads to the development of pasteurellosis infection and radiation sickness in acute form with death of all animals, mainly on the first and second days after exposure to the affecting agents. k./kg, which leads to the development of pasteurellosis infection and radiation disease in acute form with death of all animals, mainly on the first and second days after combined exposure to the affecting agents. It was found that gamma-irradiation of rabbits at a dose of 8.0 Gy, followed by infection with Pasteurella at a dose of 4.5×10³ m.k./kg, aggravated the course of the pasteurellosis process, contributed to its generalization and accelerated the death of animals.

Conclusion: Radiation-pasteurellosis affection proceeded rapidly. Animals died on 2‒13 days after the onset of the disease with an average life expectancy of 6.3 days. Exposure of rabbits to non-lethal doses of the studied agents at the indicated doses led to aggravation of the course of radiation sickness and pasteurellosis infection, causing death of all animals from radiation-pasteurellosis pathology. At autopsy of corpses of animals, which died from acute course of radiation-pasteurellosis pathology, swelling of subcutaneous tissue in the area of pharynx and intermandibular space of neck, hyperemia and enlargement of lymph nodes, numerous hemorrhages on serous and mucous membranes and in tissues of parenchymatous organs ‒ serous or serous-fibrinous exudate in thoracic and abdominal areas, pulmonary edema were found.