河北和山东部分地区猪圆环病毒2型的分离鉴定及其遗传变异分析OA

In order to understand the latest prevalence of Porcine circovirus type 2(PCV2)in Hebei and Shandong Provinces and develop the vaccines targeting the current virus,61 tissue samples were collected from pigs with suspected PCV2 infection and tested by PCR.The PCV2 positive samples were aseptically treated and then inoculated onto PK-15 cells for virus isolation and the isolated strains were identified by PCR and indirect immunofluorescence method.The complete genomes of the PCV2 isolates were amplified,cloned and sequenced for sequence alignment and phylogenetic analysis.Results showed that 32 out of 61 samples(52.4%)were positive for PCV2.Five PCV2 strains were isolated from PK-15 cells and all had a full-length genome of 1767 bp.Genetic and evolutionary analysis showed that one isolate belonged to PCV2 and four to PCV2d.Amino acid sequence analysis of the cap protein revealed multiple mutations in these five isolates and some in the antigenic epitope region.These results indicated that the infection rate of PCV2 remained high in Hebei province and PCV2d was the dominant genotype.In summary,this study provided new information for the molecular epidemiology of PCV2 and materials for vaccine development and pathogenic mechanism research.