Endogenous infection in mice irradiated with fast neutrons or gamma rays.

Abstract

Summary1. Single, 90-minute irradiation with fast neutrons within the lethal range (175-250 rep) resulted in early deaths among CF No. 1 female mice with a significant peak in the mortality curve 4-8 days after exposure. Among 129 neutron-irradiated mice (216-265 rep: LD60-98—30 days), sacrificed for bacteriological examination, positive cultures of heart's blood and/or spleen were first obtained on the 4th day, and coincided with the onset of mortality. Between the 4th and 8th days after exposure, approximately 40% of the sacrificed mice showed positive cultures. 2. After comparable irradiation with gamma rays (Co60), from 750-1300 r, deaths occurred later, with a peak approximately 12-14 days post-exposure. Gamma-irradiated mice (900-940 r) were found to have positive blood and/or spleen cultures during the latter part of the second week. There seems to be a close correlation between bacteremia and time of death following these 2 ionizing radiations. 3. All the microorganisms recovered in cultures were ...