Investigation On The Porcine Circovirus Viruses And The Establishment Of Fluorescence Quantity PCR For Porcine Circovirus Type 1

Porcine circovirus Virus type2 (PCV2)is the causative agent of postweaning multisystemic wasting syndrome (PMWS)that has become an emerging and important disease in swine. The ORF2 gene is the main region encoding the structural protein that can be used to differentiate PCV1 and PCV2. In the present study, the epidemiological disease associated with PCV2 and PCV1 infection was investigated and PCR was applied for the detection of PCV2 and PCV1 in tissues from diseased or dead pigs in South China region and High fever region.Tirthteen PCV2 isolates and eleven PCV1 isolates were isolated from the clinical samples. The complete genome sequence for the isolates were determined and compared with other PCV2 and PCV1 strains.1 144 swine tissue samples collected from South China were subjected to the nested PCR assay for both PCV1 and PCV2.The results showed that 21(14.6%))tissue samples were PCV1 positive, 40 (27.8%)PCV2 positive, and interestingly 7(4.9%)samples were positive for both the PCV1 and PCV2. 98 swine tissue samples collected from"Mystery fever syndrome"pigs were subjected to the nested PCR assay for both PCV1 and PCV2. 79.6% PCV2 positive,7% PCV2 positive. The result indicate in the"Mystery fever syndrome"pigs herds, the PCV2 infection were quite severity。2 Eleven PCV1 complete genomes were amplified from pig tissue, thirteen PCV1 complete genomes were amplified from pig tissues, The genome sequences were determined, and the results demonstrated that the complete genome of all the 11 PCV1 isolates were 1759bp in length, the complete genome of all the 13 PCV2 isolates were 1767bp in length, Five PCV2 isolates variance were very little of South China. Eight PCV2 isolates variance were prodigious of High fever region .3 A pair of primers was designed according to the PCV1 sequence in Genbank, and the ORF2 gene was amplified by polymerase chain reaction (PCR). Meanwhile, according to the known ORF2 gene sequences of PCV1 surveyed by our laboratory previously, a pair of primers and a TaqMan probe were designed. The FQ-PCR assay was carried out by quantitative concentration of serial 10 fold dilutions of pMD-ORF2 DNA by optimizing circulation parameters. Furthermore, we found the sensitivity of FQ-PCR was roughly equal to that of nPCR and was prior to that of PCR by detecting the positive field samples.