Abstract:

Porcine Hokovirus(PHoV) is a new parvovirus of pigs which was recently discovered in Hong Kong，China in 2008.In present study，a total of 147 blood samples were collected from pig farms and slaughter houses in Lanzhou，Zhangye and Tianshui city，Gansu province.Two pairs of primers were designed based on VP1 regions of PHoV genome(GenBank accession No.EU200677).One hundred and forty seven samples were detected by nested PCR(nPCR) assay for PHoV.The nPCR showed an overall prevalence of PHoV as high as 38.10%(56/147).Of which，>12-week-old pigs showed a significantly higher positive rate(55.56% ) than <6-week-old piglets(25.00%) （P<0.05），while there was no significant differences among three cities （P>0.05）.Out of the 56 positives，12 were selected in terms of geographical distribution for sequencing(GenBank accession No.：JQ177084-JQ177095).Phylogenetic analysis together with 11 reference VP1 sequences of PHoV from GenBank revealed a homology of 95.2%-99.0% among the present 12 VP1 sequences.Of which，JQ177093，JQ177085 and JQ177089 formed a separate branch in the phylogenetic tree，and other 9 together with 12 reference sequences from GenBank formed the second branch.Of the later 9，JQ177095，JQ177087 and JQ177091 formed a sub-branch closely related to JF738366 from wild boar in Romania，whereas JQ177086，JQ177090 and JQ177094 formed another sub-branch just next to HK3 from Hong-kong pigs，and the third sub-branch of JQ177088，JQ177092 and JQ177084 closely related to HK5.The present 12 PHoV-VP1 sequences shared a homogeneity of 95.2%-99.0% with Romania wild boar isolate (JF738366)，and 96.7%-99.7% with Hong Kong-originated HK1-HK6.The present findings confirmed a high prevalence of PHoVs both evolved from Romania wild boar isolate and Hong Kong pig isolates in Gansu province.