Establishment And Application Of Indirect ELISA For The Detection Of Duck Salmonella Antibodies

In this experiment duck Salmonella anatum was studied as the research object, and the indirect ELISA mothed to detect IgG antibody was established successfully by using schizolysised O7 serotype S. anatum suspension, thus this mothed was developed to detect S. anatum antibody lever and provide technical support for quality assessment and the development of a vaccine immunization program.This indirect ELISA mothed used schizolysised O7 serotype S. anatum suspension as coating antigen, and the optimal indirect ELISA reaction condition was determined as follow:the antigen covering concentration was 19.51μg/ml, coving 2 h in 37℃; closing time was 1h in 37℃; the first antibody optimal working condition was 1:200, in 37℃ 1h; the second antibody optimal working condition was 1:400, in 37℃ 1h; the blinding time was 1h in 37℃; coloring time was 15min in 37℃; and the results of block assay, reproductive assay, intersective assay and sensitivity assay was showed that this indirect ELISA method for the plague virus, duck hepatitis virus, duck plague Anatipestifer, duck Escherichia coli, Staphylococcus aureus, positive serum test results duck adenovirus was negative; blocking effect was obvious; sensitivity was more than 64 times the tube agglutination test; within the plate and coefficients of variation were between 1.46%～3.12% and 1.30%～3.17%, less than 5%, indicating good reproducibility.The serum after first propolis inactivated vaccine immunization at 5 days,10 days,15 days,20 days,25 days,35 days and after second immunization at 5 days,10 days,15 days,20 days were determined by the indirect ELISA method we established. Results showed that the OD450 value after first propolis inactivated vaccine immunization at 5 days antibody was 0.589, determined positive, then OD450 value increased gradually; at 25 days and 35 days after first immunization, OD450 values very close to 1.112 and 1.113, respectively; which rose to the peak of the antibody may be reduced or an added value to first immunization no longer increase about 1.1; after second immunization D450 value was higher, it could be included second immunization was better than first immunization; as serum of unvaccinated ducks was not collected, it was difficult to determine whether the presence of maternal antibodies ducklings at 14 days of age.