Gamma Radiation Inactivation of Coxsackievirus B-2

The radioresistance of coxsackievirus B-2 was studied when the virus was suspended in Eagle minimal essential medium, distilled water, cooked ground beef, and raw ground beef and irradiated at various temperatures in a cobalt-60 gamma radiation source. The number of surviving viruses at given doses of radiation was determined by a plaque assay system. All destruction curves indicated a first-order reaction. When the virus was irradiated in minimal essential medium at temperatures of -30, -60, and -90 C,D values (in Mrad) were 0.69, 0.59, and 0.64, respectively. When the virus was suspended in water and irradiated at -90 C, the D value was 0.53. Cooked ground beef containing the virus was irradiated at temperatures ranging from 16 to -90 C. The D values were 0.70 (16 C), 0.76 (0.5 C), 0.68 (-30 C), 0.78 (-60 C), and 0.81 (-90 C). Raw ground beef containing the virus was irradiated at -30, -60, and -90 C, and the D values were respectively 0.75, 0.71, and 0.68. The D values indicate that the rate of viral inactivation was dependent on the suspending menstrum.