Isolation And Identification Of Porcine Epidemic Diarrhea Virus And Development Of Inactivated Vaccine

Porcine epidemic diarrhea(PED)is an acute high-contact intestinal infectious disease caused by Porcine epidemic diarrhea virus(PEDV).The disease has obvious susceptibility to pigs of all ages and breeds,especially in suckling piglets,the incidence is as high as 100% and the mortality rate is 30%~80%.The disease is characterized by acute watery diarrhea,vomiting and dehydration in sick pigs.At present,the prevention and control of the disease is mainly based on vaccine immune control,but because the pathogen of the disease has been mutated in China for many years,the immune protection effect of the existing domestic vaccines in different regions is very different,and the level of aquaculture management The difference,relying solely on a single immunization,does not fully guarantee a highly uniform neutralizing antibody after immunization of the vaccine.Therefore,the market urgently needs a higher safety and protection rate of pig epidemic diarrhea vaccine to protect piglets from the prevalence of PEDV,and thus control the outbreak and spread of the disease.In this study,the small intestine tissue and contents of pigs in Gansu Province were collected for PEDV isolation and identification,and the inactivated vaccine was developed.Finally,a new exploration was made for the prevention and control of PED in Gansu.The results are as follows:1.Separation and identification of PEDVIn a pig farm with diarrhea in Gansu Province,the small intestine tissue and contents of piglets within 7 days of age due to diarrhea were collected and cultured in Vero cell culture system supplemented with 10 ?g/mL trypsin,blinded on Vero cells.After the fifth generation,obvious cytopathic changes occurred and the virus was transferred to the 10 th generation.After identification by RT-PCR and virus specificity test,it was confirmed that a porcine epidemic diarrhea virus was isolated and named as PEDV-GS10 strain.2.Development of inactivated vaccineDuring virus culture,Vero cells were subcultured in DMEM medium containing 8% newborn fetal bovine serum,and PEDV-GS10 strain was inoculated into Vero cells at a volume ratio of 0.5%,and cultured in a greenhouse at 37 °C for 48-72 h.virus.The PEDV-GS10 strain virus solution was added to a final concentration of 0.07% formaldehyde,and inactivated at 2-8 ° C for 48 h.After sterilizing and inactivation tests,the vaccine was prepared with ISA 61 VG adjuvant,and the test was found to be safe and effective for piglets.3.Field trials of vaccinesThe safety test and effectiveness test of pregnant sows showed that the pig epidemic diarrhea inactivated vaccine(GS10 strain)is safe and effective for pregnant sows,and has no effect on the number and quality of pregnant sows.The antibody continues at least until 28 days postpartum.