Optimization of the Inactivation Process of FMD Virus Serotype SAT-2 by Binary Ethyleneimine (BEI)

摘要

Complete inactivation of FMDV new isolate type SAT2 Egypt 2012 at 37oC using BEI with morality 0.1, 0.4, 0.8, 1.2 and 1.6 mM was obtained at 16,14, 10, 8 and 8 hours respectively, with inactivation rate ranged from 0.53 to 1.15 log10/hour. At 25o C the complete virus inactivation was occurred at 52, 44, 40, 36 and 36 hours post inactivation using a concentration of 0.1, 0.4, 0.8, 1.2 and 1.6 mM respectively with inactivation rate ranged between 0.16-0.24 log10/hour. Also the result of complement fixation test of FMDV type SAT2 using different BEI morality at 37oC, 25oC showed that Antigen complement fixation titer were changed before and after inactivation from 1/32 to 1/16 in 0.1, 0.4 and 0.8 Mm while from 1/32 to 1/8 in 1.2 and 1.6 mM. There was no significant difference between the use of BEI in concentration of 0.1 and 0.4 mM, and between 1.2mM and 1.6 mM, while the inactivation time decreased by approximately 8 h in the concentration of 1.2 rather than 0.1 mM, this may be very useful to finish the process of inactivation during working day or just over night. Evaluation of the immune response in Guinea pig of the vaccine prepared from different inactivated virus using different molarities of BEI and different incubating temperature was carried out and showed that the best antibody titer appeared after 28 days post vaccination using inactivated virus with molarity 0.1M BEI at incubation temperature, 37oC it reached 1.8 and 2 log10 using Serum Neutralization Test (SNT) and Indirect ELISA respectively. On the other side there was a significant reduction in the post vaccinal antibody titer appeared using inactivated virus with 0.4, 0.8, 1.2 and1.6 mM BEI while at 25oC it was 1.8 and 2.1 log10 in 0.1mM using SNT & ELISA respectively. It was clear that the optimal condition used for inactivation of FMDV SAT2 is by using BEI with a molarity of 0.1mM and incubational temperature 37oC for 16 hours as this provide a good and safe antigenic content and reduce the inactivation time.