Polyclonal hyperimmune serum against Pasteurella multocida type A:5, A:8 and A:9 was prepared in boskat rabbits. The indirect haemagglutination test (IHT) showed that such serum had an antibody titer of 1114. The immunoglobulins in the prepared antiserum were precipitated using saturated ammonium sulphate solution. Its concentration was adjusted to be 18mg/ml in normal saline then it was conjugated with horse radish peroxidase and evaluated through the application of double sandwich ELISA. It was successful to detect Pasteurella multocida antibodies in positive serum samples with strong positive reactions up to a dilution of 1:100 of
the prepared conjugate.In the present study, polymerase chain reaction (PCR) using random primer (E-20) was used to characterize and identify strains included in this study. Strains included 4 vaccinal reference strains of Pasteurella multocida, CU strain and 4 field isolates of Pasteurella multocida isolated from diseased turkeys which were identified biochemically and serologically as A:1, A:3, A3x4 and D:11. The obtained results revealed that all strains were reacted positively and in different manner with the E20 primer except the 2 field isolates. The results of these reactions demonstrated in terms of bands of different molecular weight specific to each strain. This can be used as a base for characterization and differentiation of strains involved in the present study as the 2 field strains A:1 and A:3 react with primer. Mouse protection test was performed by vaccination of mice with local fowl cholera oil adjuvant vaccine then challenge with virulent field strains A:1, A:3, D:12 and untypable isolates. Results revealed that the local fowl cholera adjuvant vaccine could protect mice against virulent challenge with A:1, A:3 and D:12 field strains but it could not be protect mice against untypable isolates