Effat, M. M1*; Abdallah, Y. A.2, Soheir, M. F.1, and Rady, M. M.3
1Microbiology and Immunology dept, National research centre, Giza, Egypt.
2Serum and Vaccine Research Institute, Abbassia, Egypt.
3Poultry Diseases dept, National Research centre, Giza, Egypt.
