| Pseudorabies,also known as ojesky disease,is a viral disease caused by pseudorabies virus,which is of great economic significance to the pig industry.Although some countries have implemented the purification strategy of porcine pseudorabies,it is still one of the most important porcine diseases in many countries,especially in areas with dense pig herds,including China.Since 2011 a variant of pseudorabies virus with enhanced pathogenicity has been prevalent in China.Even though pigs in many areas have been vaccinated,its infection rate is still high.Therefore,for China,the control and purification of porcine pseudorabies is still a huge challenge,which needs to formulate different prevention and control measures according to the prevalence of porcine pseudorabies in different regions,so as to provide a basis for the purification of the disease in China.Therefore,this study conducted epidemiological investigation and analysis of porcine pseudorabies in northern Liaoning Province,and revealed the prevalence of porcine pseudorabies in northern Liaoning Province through the amplification of virulence genes and system development analysis of different pig herds in different pig farms,wild virus infection and more serious pig farms in northern Liaoning Province.The results showed that: 1.Among the investigation results of pigs for different purposes,the PRV wild virus infection of production sows was the most serious,with the positive rate of PRV gE antibody of 46.01%,followed by breeding boars,with the positive rate of PRV gE antibody of45.52% respectively.The PRV wild virus infection rate of finishing pigs was the lowest,with26.72%,and the average PRV wild virus infection rate of pigs was 40.02%.In terms of vaccine immunization,the average positive rate of PRV gB antibody was 73.19%,and the overall antibody level was low.2.From the situation of PRV wild virus infection in pig farms in different regions,the positive rate of PRV gE antibody in pig farms in Tieling area is 46.49%,and the infection rate is the lowest.The positive rate of PRV gE antibody in pig farms in the other three areas is more than 50%,including 56.54% in Fuxin area,57.22% in Fushun area and 59.37% in Shenyang area.3.In terms of immune effect,the positive rate of PRV gB antibody in non immune field was 46%(46/100),the positive rate of PRV gB antibody in immune field was 78.18%(896/1146).The positive rate of PRV gE antibody in non immune field was 33%(33/100),the positive rate of PRV gE antibody in immune field was 42.41%(486/1146).4.PRV gE gene was amplified from the disease materials collected in different regions,and the total length of c DNA sequence was1737 bp.The results showed that the isolates of SY gE and TL gE were closely related,and the isolates of FS gE and FX gE were closely related;The PRV wild strains isolated from pig farms in northern Liaoning are the same branches as those isolated from Qingdao,Tai’an,Shandong and Hebi,Henan.SY gE,TL gE,FS gE and MK622295 1 QD2 gE has the highest nucleotide homology,99.8%-99.9%,FX gE and MK622285.1 and KF130887 The nucleotide homology of ZM gE was 99.8%.Through this investigation and analysis,it can be found that although the overall immunization level of pig farms with pseudorabies virus in northern Liaoning Province is 78%,it is still lower than 80% of the immunization standard,and immunization still needs to be strengthened.In addition,wild virus infection in pig farms is relatively common,so it is necessary to strengthen pig farm management and prevention and control measures to provide a basis for the purification of the disease. |
