| Porcine parvovirus is one of the main pathogens cause reproductive failure of bigs.It can cause stillbirths, deformities and mummified foetus and sick piglets, and it can also cause dermatitis symptoms of piglets, non-suppurative myocarditis and emaciation syndrome. PPV often infect with PRV, PCV, CSFV, PRRSV and that aggravates the damage degree of PPV. Because of widespread popularity and harm of the disease, the disease has been one hot spot of the pig disease. We isolated and identified PPV Henan local strain HP104, and studied its biological characteristics, also finished the whole genome sequencing. In order to do better to the cultivation, we explored the cultural character of HP104 on different cells. We also experimented the immunogenicity of HP 104 with the guinea pigs.Polymerase chain reaction (PCR) was used to detect the DNA of suspected porcine parvovirus (PPV) pathologic samples from Henan Province, a PPV strain HP 104 was successfully isolated by inoculating the positive pathologic material on the swine testicular (ST) cells. Biological characteristics of the virus were studied by observing the lesions of ST cell, detected TCID50 and HA titer of the virus, studied the physiochemical characteristics. Specific gene fragment was amplified by PCR and the sequence was analysed. The cells infected by the virus appeared stable CPE after 10 passages. Hemagglutination (HA) titer of the virus reached 210 at the 15th passage and the virus reached 108.5TCID50/0.1 mL at the 20th passage, the virus was not sensitive to chloroform, heat, acid and trypsin. The virus was observed to be visible round with a diameter of 23 -26 nm by electron microscopy. PCR amplification product was consistent with expectation. Compared with other PPV strains, the homology of the little gene sequence is 100%. It was confirmed that the isolated virus was belonged to porcine parvovirus.4 pairs of primers were designed according PPV sequences published on Genbank to amplify the whole genome fragments of PPV HP104, and the whole genome was sequenced. The result showed that the genome length of PPV HP 104 strain was 4679 bp. The PPV HP104 strain had the closest genetic relationship With NADL-2 strains, the PPV HP 104 strain was distant with SR-1 strains.The virus PPV HP104 was germinated on 1 strain ST cell and 3 strains PK-15 cell, and culture characteristics were compared. The result showed that the PK-15 cells of different sources had different proliferation effect. The TCID50 of PPV HP104 on ST cell was higher than that on PK-15 cells.The PPV HP104 was purified and inactivated with 0.3% formaldehyde. We mixed the white oil adjuvants with inactivated PPV suspension, after 28 days injected to guinea pigs, we used the HI to detect the antibody level which reached 128, the negative control group contain no antibody. |
