Isolation and Characterization of a Field Strain of Bovine Ephemeral Fever Virus in China

The infected blood was collected from dairy cattle showing similar Bovine Ephemera Fever (BEF) clinical signs in Taizhou area of Zhejiang province. The blood frozen-thawed 3 times was concentrated decuple by centrifugation, then the virus had 7 blind passages in suckling mice by an intracerebral inoculation route and 10 passages in BHK21 cells. The suckling mice died regularly 3-4 days after inoculation from the 3rd passage with 100% mortality rate. In BHK21 cells, the CPE occurred from the secondary passage and 80% cells approximately emerged pathological changes post-infection from the 4th passage. The virus isolated was proved to be Bovine Ephemera Fever Virus (BEFV) by RT-PCR, Transmission Electron Microscopy (TEM), Virus Neutralization (VN) test and IFA test. The virus isolated was designated JT02L. The homologies of amino acid sequence of the G gene compared with JB76H (Beijing strain), Taiwan strain and BB7721 (Australia s strain) all were above 90%.