Isolation And Evolution Of Porcine Parvovirus Strain Ppv2010

Porcine parvovirus disease is caused by porcine parvovirus (PPV), and is a propagation obstructive disease with the main features of sow abortion, fetal death, fetal malformations, mummified and weak fetal pig. Worldwide spread of PPV has affected the development of the pig farming industry seriously. In this study, a number of tissue samples were collected from a Jilin pig farm, and after blind passages, the virus produced obvious CPE on the PK-15cells. Electron microscopy and immunofluorescence analysis proved that the isolated virus is PPV, which was designate as PPV2010.Five pairs of specific primers designed according to the PPV sequence published in GenBank were used to amplify the full genome of PPV. Each PCR fragment overlapped and resulting products were cloned into pMD18-T vector, followed by identification by the restriction endonuclease and sequencing. Using DNASTAR software, the full-length PPV genome was achieved and was allocated a GenBank accession number JN872448.PPV genome, NS1gene and the VP2gene sequences published in GenBank were firstly collected by the MUSCLE, and then by Se-Al manually aligned; the optimal nucleotide substitution model of all data sets were calculated by ModelTest3.7the GTR+G+I was the best model. A phylogenetic tree was constructed by PAUP4.0. DNASTAR software was used to compare the nucleotide and amino acid homology between the strains. The results showed that PPV2010strain and BQ strain have the highest homology. The recombination of PPV was analyzed and no recombination event was occurred in PPV evolutionary process. MCC tree was built and the result showed that PPV already existed approximate164(95%HPD:55-397) years. The virus obtained in this study provided basis for further biological study of PPV and gave rise to new conclusion regarding the evolutionary divergence time of PPV.