Study On The Subunit Vaccine Of Streptococcus Suis-Haemophilus Parasuis

Streptococcus suis（SS） is the main pathogen which can lead meningitis, arthritis and hematosepsis. Haemophilus parasuis（HPS） can lead Glaser’s disease whose symptom includes hydrohymenitis, meningitis and arthritis. These two diseases usually occur at the same time, which causes great harm to the animal hunsbandy. The vaccine of SS2 and HPS popular in the market are almost inactivated vaccine at present. The lack of a vaccine against a broad spectrum of strains has limited the control of the disease.In recent years, a lot of antigen candidates protein of SS and HPS has been identified. So, the purpose of the our study is to develop a novel subunit vaccine which has cross immumity.1. The conservatism of the vaccine candidate proteinWe study the distribution of the SS2 protein HP0197, HP1036 and the HPS5 protein HPS₀6257, Pa1A in all clinical isolates and serotype at the level of DNA and protein. The result shows that HP0197 and HP 1036 show wide distribution in different clinical isolates, meanwhile HPS₀6257 and Pa1A show wide distribution in 15 different serotype.2. The preparation technology of the vaccineThe protein of HP0197, HP1036, HPS₀6257 and Pa1A can be expressed by bactertium coli（BL21）, then we tried to find the best condition of the protein expression and extaction to reduce the cost of the vaccine.3. The security of the vaccineWe can find the vaccine of great secuirity by the evaluation of the body tempreature and the apetite, then we also find that the body of the piglets can absorb the subunit vaccine very well.4. The protective efficiency of the vaccineA mouse attack protection test must be carried out to learn the effection of the vaccine preliminarily. The result shows that high level of specific antibody can be detected in the body of mouse, and the percent survival of the mouse after challenged by SS2, HPS4 and HPS5 are respectively 80%,60%,90%.By means of immuniting the piglets, we learn the safty of the vaccine, then evaluate the level of the antibody, the end we protract and compare the curve of the vaccine made by white oil adjuvant and a novel adjuvant. The results show that the vaccine is very safe, high level （1:1280） of specific antibody can be detected in the body of piglets, and the level of specifigic antibody indused by the vaccine made by white oil adjuvant are higher than the one indused by the vaccine made by the novel adjuvant. The percent survival of the piglets after challenged by SS2（05ZY）, HPS4（MD0322） and HPS5（SH0165） are considerible and the percent survival of the mouse after challenged by SS2, HPS4 and HPS5 are respectively 80%,80%,60%. We evaluated the content of bacteria in the tissue and organ, at the same time, we made the pathological section. We found that the content of bacteria in the immune class lower than the one in the blank class. In histology, we can find the pathological degree of the blank class is more serious than the one of the immune class.