Abstract:

In this study, an unknown virus was isolated from rectal swabs of cattle with severe diarrhea and hemorrhagic dysentery in Beijing. The unknown virus was identified as non-enveloped particles about 30 nm in diameter and containing RNA genome by physicochemical characteristics analysis. All of four layers which were purified by cesium chloride density gradient centrifugation were amplified with random polymerase chain reaction (PCR), and the products from layer 2 ranged mainly from 500 to 1 500 bp, showing comet tail-shaped entrainment phenomena, were purified and sequenced. The sequence blast results showed that the virus shared high gene homology with bovine enterovirus type 2. Therefore, specific primers of bovine enterovirus type 2 was used further to identify the virus, and the unknown virus was finally verified exactly belonging to BEV2 (93% nucleotide identity). Two healthy adult cattle were inoculated with the virus as experiment animals, but no clinical symptoms appeared, although antigen and serum antibody were positive after challenge.