Bacteriological Studies on Mice Exposed to Supralethal Doses of Ionizing Radiations: II. Fast Neutron and X-Radiation from Laboratory Sources

bacteria was found to occur in a high percentage of mice after exposure to supralethal doses of neutron radiation (510 rads) or x radiation (1340 rads), doses which result in death within 5 days probably from gastrointestimal injury. The incldence of infection paralleled the increase in deaths. During the first 60 hours bacteria were isolated primarily from the spleen. After that time a bacteremia developed. The administration of 10 mg of streptomycin and 4000 units of penicillin drastically decreased the incidence of infection but did not alter either the per cent of deaths or the mean survival time of the neutron-irradiated mice, although the mean survival time of the x-irradiated mice was lengthened somewhat. Hence, it must be concluded that postirradiation infectlon plays only a minor role, if any, as a cause of death after exposure to these doses of ionizing radiation. (auth)