The Investigate Of Molecular Epidemiology Of PCV2 In Anhui

Pig circovirus disease as one of newly identified diseases is associated with postweaning multisystemic wasting syndrome (PMWS). The patients represent the congenital tremors and PMWS in clinic. PCV2 is considered as the pathogen of PMWS. It dose not only induce PMWS, but also is associated with dermatitis and nephropathy syndrome,congenital tremors,proliferative and necrotizing pneumonia and reproductive disorders. PCV2 brought on tremendous economic losses for swine production, so the related investigation is important for us to prevent and treat PCV2.Firstly, according to the published ORF2 genomic sequence of porcine PCV2, we designed a pair of specific primers. The assay of all 2 PCV2 referential strains can amplify the products of 630bp, but not PCV1, CCV and HCV. The sensitive experiment indicated that PCV2 5fg DNA that was diluted to as low as 1/100 was still detected by the PCR. Simultaneously, 120 samples, which were collected from slaughterhouses of Suzhou, Huaining, Fuyang and Hefei, and 30 samples, which were collected from 3 different hogpens of Shucheng, Chaohu and Huajie, were detected by using developed PCR. The results indicated that the PCV2 infection abroad existed in Anhui areas. Thereinto, the positive ratio of Suzhou slaughterhouse was 6.1%, the same as Hefei, Fuyang was 10%, but Huaining was 23.3%. To 3 different hogpens detected, the results indicated that positive ratio of Shucheng hogpen was 20%, Chaohu was 20% while Huajie was 70%.Secondly, for knowing tissue status of infected PCV2 from pathogen, we separately detected the different tissue of detected positive samples. It included spleen, lung, kidney, lymph, and so on. The results indicated that the different tissues were detected PCV2 positive, but the positive ratio was different. The positive ratio of spleen and lymph reached 100%, and it reduced immunity of swine; the positive ratio of lung was 80%, the positive ratio of kidney was about 40%.Thirdly,through amplifying positive samples by PCR and analyzing molecular characteristics of ORF2 region and constructing their phylogenic trees, the results indicated four positive strains connected to AY484416 referential strain from UK. They consisted of an embranchment, and the embranchment was close to three strains of DQ795679, AY556476 and AY556473 in phylogenic tree. But the distance was far away from AY325495 strain and AY556474 strain in phylogenic tree.