Characterization And Preparation Of Porcine Transmissible Gastroenteritis Virus Vaccine Strain

Transmissible gastroenteritis （TGE） is a highly contagious disease of swine caused byTransmissible gastroenteritis virus （TGEV）. TGEV belongs to a member of Coronaviridae family.Vaccination is an effective measure for control of TGEV. As a consequence, development ofvaccines against TGEV becomes important. Availability of purified vaccine virus is a prerequistfor development of vaccine.In this study, We cultured the TGEV strain HR/DN1kept in our laboratory according to theveterinary biological products registered classification and data requirements on the basis ofprevious experiments. After subculturing dozens of generations, the virus titer has been stable at10^6.0-10^7.0/0.1mL. And then, a series of physical and chemical testing of seed virus had beentested:1. the test of the type of nucleic acid and the lipid solvent sensitivity test confirmed thatTGEV was RNA virus with capsule membrane;2. pH3.0acid experiments confirmed that the viruswas more stable under the condition of low temperature, and the virus would be inactivated underhigh temperature.3.Heat sensitive experiments demonstrated TGEV was not heat resistant, and thevirus was relatively stable under the condition of50℃, but with the increase of temperature, thevirus titer would decline. We also employed indirect immunofluorescence assay, RT-PCR etc. toidentify the virus. The end, reference to the veterinary drug standard of the People’s Republic ofChina,purity tests on the cell and virus were carried out respectively--bacteria, mold, mycoplasmaand exogenous virus pollution detection, proving both the cells and virus were non-pollution.Experimental results showed that the virus had the characteristic of high titer, subculturingsteady, etc. According to the basic conditions for virus seed preparation, we established theoriginal seed batch, basic seed batch, after virus propagation. The establishment of virus seed bankprovided a solid foundation for the next experiments on the swine and vaccine development.