Comparative Histological And Pathologic Study On Large-white And Tongcheng Pigs That Infected HP-PRRSV

Porcine Reproductive and Respiratory Syndrome (PRRSV) is the most important infections disease can cause either reproductive failure or respiratory disease. Reproductive failure is characterized by abortion or delivery of stillborn, near-full-term fetuses or premature,weak piglets. The pathologic characteristic of the infected PRRSV pigs was not all the same in reported papers, the susceptibility is one of the important infectious factor besides of the different type of virus and different route of infection. Is it different piece can cause different pathological characteristic? Nowadays, have been not reported. Therefore the present study attempted to carry out an research on this area. The contents of this study were as follows:Eighteen pigs of tongcheng and large white were killed, View and record the pathological anatomy. Results showed that the injure of the large-white lungs is more seriously than tongcheng pigs, petechial hemorrhages were seen on the surfaces of the kidney and all the lymph node of body are swelling and bleeded. However, the control group is normal.Histopathological changes of the infected group show that interstitial pneumonia, there are more exudate in large-white alveolar spaces than tongcheng infected group (p<0.05). The structure of the infected group tonsil is unclear,there are more necrolysis lymphocytes and less lymph follicles (p<0.05). The germinal centers of the spleen were not observed in the infected group, there is massive haemorrhage in the spleen capsule and are more necrolysis lymphocytes.The control group is normal.The immunohistochemistry staining of the antigen of PRRSV showed that there were yellow positive plasmids in cytoplasm of alveolar macrophage (AM), the type II alveolar epithelium and lymphocyte. There are more positive signal in large-white infected group than tongcheng infected group (p<0.05). Antigen of PRRSV distributed in the cytoplasm of mononuclear phagocyte and lymphocyte in spleen, tonsil, hilar lymph node, mandibular node, cervical lymph node and inguinal lymph node. In the four kinds of lymph node, the positive signal in large-white infected group were more than in tongcheng infected group(p<0.01), Moreover, the antigen of PRRSV distributed in the hilar lymph node and cervical lymph node is more than mandibular node and inguinal lymph node (p＜0.01).The immunohistochemistry staining of the antigen of TNF-a showed that there were yellow positive plasmids in cytoplasm of macrophage and lymphocyte. Antigen of TNF-a distributed in the control group than in infected group in spleen, tonsil, hilar lymph node and mandibular node.The results indicated that there were pathologic lesions in tongcheng and large-white infected PRRSV group, and the lesions of large-white infected group was more seriously than tongcheng infected group. The distribution of PRRSV in large-white group was more than tongcheng. The distribution of TNF-a was not all the same.The date show that Large-white pigs is susceptibility to PRRSV than tongcheng pigs.