Study On The Detection Methods Of Porcine Proliferative Enteropenthy

Porcine proliferative enteritis is a contact intestinal infectious disease of pigs caused by Lawsonia intracellularis. PPE known as necrotic ileitis, Porcine inestinal adnomatosis,regional ileitis and proliferative haemorrhagic enteropathy.It often occurred on weaned piglets of 6-20 week old, and presented in many countries and regions. These also can cause enormous economic losses. Therefore the prevention and control of the disease has become very necessary and urgent particularly. According to the epidemic characteristics of PPE, we observed the clinical symptoms pathological sections and established the specific PCR detection methods for LI in vitro.The specific PCR detection method has the merits of short time, high sensitivity.It is a good diagnostic method for the early detection of infection of pathogens,and important to prevent and control the outbreaks of PPE.The establishment of PCR diagnostic technique fill the gaps in the clinical applications and diagnosis.The content and results of this paper are as follow:1. The observation of clinic symptom,autopsy changeand histopathology on PPEIn this study, we observed the clinical symptoms and pathological changes in sick pigs. we observed histopathology changes of sicked section of intestine through HE staining, Ziehl-Neelsen's acid-fast staining, Giemsa staining and Gram staining and so on.The results showed that the main clinical symptoms manifested as anemia, weight loss, sudden death in acute cases; autopsy mainly for ileitis. Autopsy shows that the most significant characteristic is the formation of mucous membrane of brain-like folds back, Porcine inestinal adnomatosis have thickened ileum, intestinal diameter increased, Histopathological observed shows thar the disease was characterized microscopically by an abnormal and marked proliferation of immature epithelial cells in the crypts and infection of these cells.The The determination of microscope after different staining can be seen curved rod-shaped intracellular bacteria Lawson displaying different colored. This method can be used as supplementary means to diagnose the disease.2. A PCR method for detection of LI in feces of PPE-infected live pigs was established for the first time in China.According to LI 16s of gene sequence in GenBank,a pair of primers were designed and synthesized. The system and condition of PCR were optimized. The sensitivity and the specificity tests were performed.The results showed the method was highly sensitive and specific. The specific amplified band with about 210bp was obtained.as low as 1.0ng of DNA of LI was could be detected. The method is rapid and accurate,which can meet the requirement of early monitoring of LI.It provides the fasible technology method to prevent PPE in time.