Studies On The Pathogenicity Of Streptococcus Suis Serotype 2 To Minipig

Streptococcus suis is an important amphixenosis that cause serious diseases such as meningitis,arthritis,encarditis,septicemia and pneumonia.While 35 serotypes (1–34 and 1/2)have been identified, serotype 2 is considered the most prevalent and the most virulent in pigs.The disease pose a great threaten to the public health,and should be given full consideration.Objective: To establish the fluorescent quantitative PCR detection method of Streptococcus suis ,to detect the dynamic distribution of Streptococcus suis type 2 in blood of pigs infection with s.suis serotype 2; Animal models of minipig infected with SH-08 was established,the pathological changes was observedMethods: Based on the glutamate dehydrogenase of Streptococcus suis type 2 gene, TaqMan probe quantitative PCR method was established to detect bacteria of blood. Animal models of minipig infected with SH-08 was established successfully, pathological damage was observed by microscope.Results: The results showed that bactria 24h after infection was able to detect fluorescence signal , it was not detected on 7d after infection, GDH gene copy in the blood could reach a maximum to 104.51 .Clinical symptoms manifested as sepsis and arthritis, histopathological examination revealed that the main organ congestion and hemorrhage, interstitial pneumonia.Conclusion:A TaqMan probe quantitative PCR on Streptococcus suis was established successfully, Growth Rule on bacteria from the blood of pigs infected was analysised. Pathological changes were found, such as granular degeneration and vacuolar degeneration of myocardial cell;hemorrhage, vacuolar degeneration and necrosis of liver cell in liver; necrotizing inflammation in the spleen; interstitial pneumonia;glomerular nephritis; fibrin exudation from tonsil crypt, degeneration and loss of epithelial cell in tonsil; necrosis in lymph node.