INCIDENCE OF ENDOGENOUS BACTERIAL INFECTION IN MURINE RADIATION CHIMERAS WITH SECONDARY DISEASE

Pathological changes indicative of bacterial infection were reported by several investigators in animals with secondary disease. Cultural methods were used in experiments to determine whether bacterial infection actually does occur in chimeras with this syndrome. Four hundred and twenty-one specific-pathogen-free mice showing well-developed secondary disease were sacrificed between days 29 and 52 postirradiation. Their livers and spleens were excised and homogenized in tissue grinders. The organ homogenates and a drop of heart''s blood from each mouse were cultured on bacteriological media both aerobically and anaerobically. Fifty-seven percent of the animals had positive liver cultures, 41% had positive spleen cultures, and 25% had bacteremia as indicated by positive heart''s blood cultures. The organisms cultured from these organs were usually members of the chimeras'' enteric flora.