Studies On Biologic Characteristics Of Streptococcus Suis 2 And Inactive Vaccine With Propolis As Adjuvant

Streptococcosis of suis is one of the major communicable diseases in pig farm. There are many serotype of streptococcus suis and streptococcus suis 2 is the most fortis in virulence. There were few researchs about streptococcus suis 2 in china.Streptococcus suis 2 need eutrophy medium to be cultured. Streptococcus suis 2 can grew well on THB,GMTB and brain-heart medium,They grow badly on common culture medium.If they culture on blood plate ,they can grow to conglboat,microprominence,blink andβ-haemolytic's microcolony. They can agglutinate streptococcus suis 2's positive serum.In this article,we construct a method of PCR to identificate steptococcus suis 2.Use the PCR method we make sure that two main virulent factor MRP and EF are in the ten strains which we have studied.The PCR method we have constructed can help we to make sure whether the strain which we have studied is streptococcus suis 2 or not and whether they own virulent factor MRP,EF. The sensitivity of this PCR method can get to 20CFU/ml.Through the research about the pathogensis to experimental animal of streptococcus suis 2,we can concloud that kunming mouse are not sensitive to steptococcus suis to,some streptococcus suis 2 are fatal to Balb/c mouse.Different stains's virulcnce are variance to pig.If pigs are infected with streptococcus suis 2, its can present meningitis or arthritis and the bacterium can be found in pars encephalica,heart,liver,spleen,lung and joint capsule.Most internal organ can show macroscopic pathological change such as congestion,punctate hemorrhage,infarct and etal..By the pathological section which stained by HE,we can find that congestion of small vessels,serosity exudation,phlegmonosi's cell infiltrate,segmented cell cytosis in mening,lungs,liver etal.Base on the research about the bionomics of streptococcus suis 2,we choose two strains which have the higher virulent and well in immunogenicity to prepare inactivated vaccine.In the prepare of vaccine,we used proplis as adjuvant。In the prepare, the difficulty is how to make the proplis dissolve in water liquor.We solved this problem successfully by ues emuldifier.By use proplis as adjuvant,the vaccine's effection get improved,and immunine stage is longer.On the other hand ,use proplis as adjuvant is more safe compare to white oil and aluminium hydrate as adjuvant.