Performance decrement after combined exposure to ionizing radiation and Shigella sonnei

Abstract

Ionizing radiation could increase morbidity from common bacterial infections in military personnel on the modern battle-field. The combined effects of a sublethal dose of ionizing radiation and the bacterial diarrheal agent Shigella sonnei on body weight and forelimb grip strength in mice were assessed over a 30-day period. Individually housed B6D2F1 female mice were divided into four groups: control, sham irradiation + garage with saline vehicle 3 Gy 60Co gamma radiation at 0.4 Gy/min radiation + saline gavage sham irradiation + 1.3 × 108 colony-forming units (CFUS) S. sonnei via gavage, administered 4 days postirradiation and the combination of 3 Gy 60Co gamma radiation + 1.3 × 108 CFUs S. sonnei. Behavioral tests were conducted 3 days preirradiation and on days 9, 14, and 22 postirradiation. Body weight was significantly reduced in the radiation ÷ Shigella group on days 5 to 10 postirradiation. Forelimb grip strength was reduced for mice in the radiation + Shigella group on days 9 and 14 postirradiation. These data demonstrate that an exposure to gamma radiation in combination with the bacterial agent S. sonnei can lead to a synergistic loss of body weight and degradation in performance.