Study On The Inulin-adjuvant Multiple Inactivated Vaccine Of Four Kinds Of Avian Pathogenic Bacteria

Avian Pasteurella multocida is a contagious bacterial disease that can endanger a wide range of birds and has a high morbidity and mortality.Chicken Pseudomonas aeruginosa is a conditional opportunistic disease in chickens.It can occur in chickens of all ages,with a mortality rate of over 90%.In addition,pullorum and shigellosis of chicken disease,but also endanger the health development of poultry industry.At present,in domestic and abroad many bacterial diseases of poultry once appear,it is very difficult to control,will cause a lot of economic losses in a short time,so we should pay attention to the prevention and control of bacterial diseases in poultry.Current therapy of poultry bacterial diseases is antibiotic treatment measures.it can kill pathogens in a certain extent,However,the problem of drug resistance caused by long-term drug use is becoming more and more serious and can not be ignored.What's more,antibiotics can affect the economic value of birds because of side effects.For the prevention and treatment of most infectious diseases,immunization is an ideal way to control the spread of disease.In recent years,with the progress of the times and the further development of aquaculture,poultry disease epidemic has many new features,the mixed infection of various pathogenic bacteria is one of its.The multiple inactivated vaccine due to the prevention of various diseases at the same time and has low cost,thus showing a good prospect.In order to investigate the adjuvant effect of inulin on four common poultry bacterial disease inactivated vaccine,the avian Pasteurella multocida,Salmonella pullorum,Shigella and Pseudomonas aeruginosa are cultured until the concentration to 2×1010 cfu/m L,after mixing proportionally,inactivated the misxed bacterial solution by adding the formaldehyde with a final concentration of 0.45% at a temperature of 37 degrees for 24 hours.Then we manufacture the oil-emulsion and inulin-adjuvant inactivated vaccine.Through the test,the stability and safety of the two vaccines are in line with the requirements.Then animal tests were used to detect the effect of two kinds of vaccines,the results show that with the prolonged time of immunization,serum antibody levels against four pathogens show a gradual upward trend,At sixth weeks after the two immunizations,the antibody levels reached the highest level in each group.The antibodies values of OD490 of the group oil emulsion vaccine group against Avian Pasteurella multocida,Salmonella pullorum,Shigella andPseudomonas aeruginosa are 0.825,1.015,1.077 and 1.089,the corresponding value of inulin vaccine group are 0.913,1.066,1.097 and 1.302,it is slightly higher than that of oil emulsion vaccine group.The toxicity test showed that two kinds of inactivated vaccine could provide more than 80% protection for the experimental animals,and had good protective effect.The inulin-adjuvant multiple inactivated vaccine was stored for 3 months and 6months in a refrigerator at a temperature of 4 degrees,then take the animal experiment to test the immune effect.The results show that inulin-adjuvant multiple inactivated vaccine can induce immune reaction of four kinds of pathogenic bacteria after 6months,The antibody level increase with the time of immunization,at sixth weeks after two immunization,the antibody level reached the highest.At this time the highest value of OD490 of the 3 months group against avian Pasteurella multocida,Salmonella pullorum,Shigella and Pseudomonas aeruginosa are 0.805,0.861,0.834,0.971,the six months group are 0.689,0.789,0.704.0.774.The protection rate of two groups are all more than 60%.According to the degree of absorption and solubility of inulin,the adjuvant group was divided into five groups: the final concentration of 10%,20%,30%,40% and 50%.The results showed that with the extension of immune time,the serum antibody levels against four pathogens show a trend of gradual increase.At sixth weeks after two immunizations,antibody OD490 reached the highest level in each group.The data can be obtained,the most suitable concentration of inulin for avian Pasteurella multocida,Salmonella pullorum,Shigella and Pseudomonas aeruginosa are 40%,30%,40% and 30%,the highest antibody OD490 value are 1.164,1.320,1.244,1.276.According to the test results and combined with the actual conditions,the optimum concentration is 30%.Therefore,it provides a reference for the development of inactivated vaccine against avian bacterial disease.