Isolation And Identification Of New-castle Virus From Egg-layer Poultry

Newcastle disease Is an acute virulent infectious disease (ND), caused by Newcastle diseasevirus (NDV), mainly infecting birds. Newcastle disease was one of the main infectiousdiseases; seriously harmed our country and the world industry. To a certain extent, Newcastledisease was under control with the vaccination, but in the existence of immune selectionpressure, NDV virulence had a tendency to strengthen, make the immune chickens disease.The range of feeding farm was10000breeding egg-laying chickens flock. The disease broke out,characterized by depression, inappetence, yellowish-green dejacta, mortality rising rapidly,more than400death in the peak et al. we suspected that it was Newcastle disease infected, Wehas made the comprehensive diagnosis to and the etiology for the virus. The result showedthat the typical symptoms were characterized by haemorrhage of the gland stomach nippleand haemorrhage between glandular and muscular stomach, mucosa haemorrhage, ulcer ofduodenum, jejunum, ileum lymphatic follicles, swelling and diarrhea of caecum tonsil,spotted diarrhea of rectum mucous membrane, hemorrhagic catarrhal inflammation ofrespiratory tract mucous. The histopathology is duodenal villi broken, mucosal epithelial cellnecrosis, hyperaemia, edema, diarrhea and haemorrhage mucosa muscular, edema andhaemorrhage of mucosa lamina proprias, a large number of lymphocyte infiltration,meningeal congestion, haemorrhage, blood vessel sleeve phenomenon, focal, diffusehyperplasia of glial cells, satellite phenomenon, neuronophagia, lymphocyte diffuseinfiltration under leptomeninges. Newcastle disease antibody levels increased significantlyafter15days. The average valence of7degrees is2.22times early onset, more than sevendegrees accounted for60%,11more than10%. A new-castle virus was isolated from lung ofegg-layer poultry, The isolated virus could grow in chicken embryo fibroblast cells (CEF)with10-4.8TCID50/0.1mL, typical cytopathic effect was observed. According to the conservedregion of duck original EDSV sequence, a pair of primers was designed for PCR. The700band was observed, demonstrated the infection of new-castle disease. At histopathology, thecharacterized lesion was observed, congestion of brain membrane, hemorrhage andcongestion of duodenum, lymphocytic necrosis in lymphocytic nodular.