Methods for Inactivation of Venezuelan Equine Encephalitis Virus
Technical Report,01 Jan 2018,31 Dec 2018
U.S. Army Combat Capabilities Development Command Chemical Biological Center APG United States
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We used Venezuelan equine encephalitis VEE virus strain TC-83 as a model to study the effects of chemical, thermal, and irradiation conditions on infectivity of single-stranded positive RNA viruses. Our data showed that exposure of the virus to 65 degrees C for 5-15 min resulted in a 5-6 log reduction of virus infectivity. Treatment with 100-500 mM NaOH caused at least a 4 log reduction in infectivity. Treatment with Beta-propiolactone at 50-200 mM concentrations for 15-60 min caused complete or near-complete loss of virus infectivity. Treatment with TRIzol LS reagent at a 31 vv TRIzol reagentvirus suspension 1 x 107 TCID50mL, where TCID50 is the tissue-culture infective dose that will result in 50 percent culture infection induced complete loss of infectivity. Effects of increasing doses of cobalt-60 irradiation 1-40 kGy showed a linear inverse relationship between irradiation dose and virus infectivity as measured by TCID50 assay. Irradiation doses of 20 kGy caused 4 log reduction in infectivity. At the 40 kGy dose, complete loss of infectivity occurred when a virus titer was 1 x 107 TCID50mL. From these results, we estimate the 1 log reduction dose and sterility assurance level to be approximately 5.5 and 32.9 kGy, respectively.