Abstract

To the best of our knowledge, the present study was the first to address the accuracy of using fluorescein-conjugated polyclonal antibodies in routine diagnosis of AEV in Egypt. For raising of anti AEV-hyperimmune sera, a total of 10 male boskat rabbits, 10 male guinea pigs and 2 male goats were used. The Mean SN antibody titers were estimated at weekly intervals and results revealed that they are gradually increased and reached to the peak level at the 5th week post-immunization with a mean titer of 256, 128 and 512 in the sera of rabbits, guinea pigs and goats, respectively. The immunoglobulin contents of the prepared antisera were precipitated by ammonium sulphate and then conjugated with FITC. In order to evaluate the accuracy of the prepared conjugates in diagnostic purposes, direct FAT was carried out on AEV-infected Vero cells using ten-fold serial dilutions of the conjugated immunoglobulins. Rabbit, guinea pig and goat conjugates showed clear positive reactions up to the dilution of 1/100000, 1/10000 and 1/1000000, respectively. The overall findings revealed that accurate and precise diagnosis of AE could be achieved by direct FAT using fluorescein-conjugated anti-rabbit and anti-goat AEV polyclonal antibodies.

Key words: Avian encephalomyelitis virus, Hyperimmune sera, Fluorescien-isothiocyanate.