الفهرس | Only 14 pages are availabe for public view |
Abstract The goal of this study is a trial to prepare different types of Salmonella Typhimurium vaccines ”local isolate” (Formalized Inactivated, Gamma-Irradiated inactivated by three doses of radiation ”3.5, 4.5 and 5.5 KGy” and Vector vaccines) and evaluate these prepared vaccines through performing quality control tests; purity, sterility and safety tests and assess their immunological efficacy in vaccinated birds, determination of the protection percentage, shedding of Salmonella Typhimurium in the intestinal content as well as the effect of these vaccines on internal organs (Liver, heart and spleen) as clearance test and finally estimation of the humoral immune response in vaccinated birds using ELISA and compare these findings with results of another imported living attenuated Salmonella Typhimurium vaccine. The obtained results showed that all the prepared vaccines are safe, pure and not contaminated with any extraneous contaminants. Challenge test after inoculation of the vaccinated different chicken groups with virulent Salmonella Typhimurium strain which revealed that the use of irradiated vaccines are the most effective and protective vaccines than other prepared vaccine. Shedding test revealed the use of irradiated vaccine (3.5 KGy) or vector one is more effective in reduction of cecal colonization than other types of the prepared vaccines. Clearance test classified the vaccinated groups into 3 categories; first one has the lowest value of reisolation which means the highest value of clearance represented by “4.5 KGy” irradiated vaccine group, followed by formalized, “3.5 KGy” irradiated, “5.5 KGy” irradiated and vector vaccines then finally the highest value of reisolation category is the living attenuated vaccine and control groups. Generally in could be concluded that “4.5 KGy” irradiated vaccine gave the best clearance value than other types of the prepared vaccines. Statistically, there is a significant difference between groups with special reference to group (4) (vaccinated with irradiated ”4.5 KGy” inactivated Salmonella Typhimurium vaccine). Generally, although all the prepared Salmonella Typhimurium vaccines are proved to be safe, potent and protective but it could be concluded that the ”4.5 KGy” irradiated inactivated Salmonella Typhimurium vaccine gave the best and highest values of the immunological parameters during assessment of the prepared vaccines through whole the length of the experiment and it could be used safely to immunize the chicken against infection with Salmonella Typhimurium. |