Investigation Of Pseudorabies In Shaanxi Province And Its Gene Sequence Analysis

Pseudorabies(PR) is first found in 1813 in United States, and now worldwidely spread in 50 countries and regions. Pseudorabies is first reported in China by Liu Yongchun in 1948.Since then, Pseudorabies are widely popular in Henan, Gansu, Guangxi and other 31 provinces. The prevalence and spreading of Pseudorabies has brought huge losses to the breeding industry and agricultural economy of China, and it is an important disease of the breeding industry. Now, some European countries through the use of gene-deleted vaccine combined with the wild virus antibody ELISA detection method could be a fundamental solution to Pseudorabies. Most pig farms in China that use efficient pig Pseudorabies gene-deleted vaccine on the purification of piggery PR work has achieved remarkable results,and has greatly reduced the mortality rate of the disease. Although the PR incidence is becoming less popular, but latent infections of the disease is still very serious.The spread and prevalence of Pseudorabies in Shanxi Province has caused great economic losses. In order to investigate the infection status of PRV wild isolate in the farms of different area.In Shaanxi Province, in recent years, the PRV serum antibodies of 1240 serum samples from different batches collected from 11 cities were detected by PRV g E-ELISA antibody detection kit. The serological survey result has showed that the antibody positive rates in different area of Shanxi Province ranges from 0% to 46.44%, and the average positive rates is18.46%. There were 41 PRV antibody positive farms, and the average positive rates of farms is 46.59%, and the positive rates of farms in different area ranges from 37.50% to 87.50%.These results show that the use of gene-deleted vaccine is playing a important role, and has effectively reduced the incidence of the disease, but most farms have not completely eradicated the disease, indeed in some of the farms the positive rate is 100%. This shows that some pigs in farms do not produce antibodies, thus they are in a vulnerable state.In November 2015, the PRV natural infection occurred in a farm in Hanzhong of Shanxi Province. More than 20 of the newly born piglets showed vomit, diarrhoea and the neurological symptoms such as muscle trembling, hind limb parlysis and four limbs swimming sliding. The treatment by a variety of antibiotic had no effects. The sick pigs were becoming dead one after another after 2 to 3 days. The mortality rate was up to 100%.Necropsies were performed on the dead piglets. The main pathological changes of thesesamples has revealed meningeal congestion,pulmonary congestion and edema, liver congestion and canous necrosis focuses. According to the clinical symptoms and pathological changes, the disease was preliminarily diagnosed as Pseudorabies. Subsequently, we collected the lungs, liver, spleen, kidney, heart and other organs and brain, intestinal contents and blood,by PCR detection, pathogen isolation, negative staining electron microscope observation and animal inoculation test, we could make sure it was PRV infection.gE can be used as a marker gene to distinguish infected animals from vaccinated animals,to remove positive infection of PRV animals, this can be a good way to eradicate the disease.Through on separation and identification of the PRV strains HZ-2015 of g e, and g b gene clone, and on its HIV force gene of nucleotide and the amino acids is derived sequence and both at home and abroad has separation identification of more strains PRV for homologous sex compared, and analysis, draws Gene evolution tree, understand and master PRV HZ-2015 strains genetic variation status, this work can provide basic information and science basis for Shanxi Province PRV of epidemic learn research, the diagnosis and prevention and cure,then we can formulate an integrated scheme to prevention PR, and reduce the loss of the disease of swine industry in our province.