Molecular Epidemiology Of Classical Swine Fever Virus Isolatedfrom Three Province Of Northwest Of China In Recent Years

The E2 gene nucleotide sequences of nine field strains of Classical Swine Fever virus (CSFV) isolated from Gansu, Ningxia and Qinghai province of China from 2002 to 2006 were amplified by reverse transcription (RT) and nested polymerase chain reaction (nPCR), and then, the amplified fragments were cloned and sequenced. The E2 nucleotide sequences and the deduced amino acid sequences of nine strains and C-strain were compared and analyzed by DNAStar software. The further study on genetic relationship was done by phylogenic tree constructed on the base of analyzing the dataset of E2 gene with computer software. The result revealed that the homology of the nucleotide sequences between five field strains and the C-strain were from 79.5 to 95.7 percent and the deduced amino acid sequences were from 87.3 to 96.2 percent and they were classified into two different Group in the phylogenetic tree, two of the five recent field strains belong to Subgroup 1.1 which contain Shimen strain and C-strain, and the other three strains belong to Subgroup 2.1.