Investigation Of Pig Infected With PRRSV And PCV2 In Jilin Area And Analysis Of PRRSV Nsp2 Gene Genovariation

As the demand of pork increased year by year,it is often seen pathogeny infected swines due to the continuously substantial economic losses to the pig industry.Porcine circovirus-associated disease(PCVAD)and Porcine reproductive and respiratory syndrome(PRRS)are more common in feeding,Gene recombinations of attenuated vaccine strains and street strains have been enforced genovariation trendency of PRRSV.Particularly,NADC30-like strain been inducing complexity and difficulty of clinical treatment.For the purpose of detection swines mix-infection with PCV2 and PRRSV,in this study we statisticsed and analysised inspection time,areas,age,immunity,clinical symptoms,necropsy of swines mixed-infection in Jilin area.We amplicated ORF1 and NSP2 of PCV2 and PRRSV by PCR,respectively.We had detected 86 suspectial material of nine areas in Jilin area.The result shown the rate of PCV2 positive and PRRSV was 43% and 48.8%,respectively.And 30 mix-infection with PCV2 and PRRSV.As the meanwhile,we found that mix-infection in December extremely significant then other months and imported swines from external always induced mixed-infection,and piglets infected with PRRSV were signification increase.In the paper,we had detected 42 PRRSV positive via detected Nsp2 strain and compared gene sequences,the result shown that 9 classical strains,11 highly pathogenic strains,22 NADC30-like strain,and we found swines still can be infected after injured vaccine PRRSV,which couldn't prevent swines from infection.The result of phylogenetic tree enlightens us that we ampliciated Nsp2 of NADC30-like strain,which nucleotide and amino acid borth have the same bases deletion with NADC30.However there are 7 strains with bases deletion at 868~873,which indicates that the new genovariation.In this paper,we found mixed-infection of PCV2 and PRRSV in Jilin area was 34.9% and the rate of NADC30-like strain was 52.4%,what enlightens us is that NADC30-like strain has been becomed the common strain of PRRSV.