Genotyping of bovine viral diarrhea viruses from cattle in China between 2005 and 2008.

Eighteen bovine viral diarrhea viruses (BVDV) from cattle in China between 2005 and 2008 were genetically typed by sequencing of the 5'-untranslated region (5'-UTR) of the viral genome and for selected isolates the N(pro) region. Phylogenetic reconstructions indicated that all of the 18 BVDV positive samples examined in this work clustered within the BVDV type 1 genotype. Of the 15 previously described subgenotypes of BVDV1 (1a-1o), 12 of the samples examined in this work clustered with the Chinese BVDV ZM-95 strain of pig origin, which was the prototype of BVDV1m, while 2 samples clustered with the BVDV1b. But 4 samples formed a separate group appearing to be a potentially new subgenotype, which was tentatively typed as "BVDV1p". Based on these results there appears to be highly genetic variation within the Chinese BVDV field isolates. As well, the phylogenetic reconstructions indicate that the clustering of the Chinese BVDV1m subgenotype in the phylogenetic tree is a result of geographic isolation. The information obtained from this work will be useful when carrying out epidemiological surveys of BVDV detected in China, especially for the BVDV1m detection in Chinese cattle.