Preparation and Evaluation of Fluorescein Isothiocyanate-Conjugated Polyclonal Antibodies for Rapid Detection of Duck Viral Enteritis (Duck Plague)

The main goal of the current study was to prepare and evaluate the suitability of fluorescein-conjugated anti-Duck enteritis virus polyclonal antibodies for routine diagnosis and research purposes. A total of 22 animals (10 rabbits, 10 guinea pigs and 2 goats) were immunized subcutaneously with Live attenuated DEV vaccine (Jansen strain) containing 106 EID50/ml. Rabbits and guinea pigs received 0.5 ml per dose, meanwhile goats received 1ml. A total of five doses with 7 day intervals were applied and the last dose was simultaneously injected with Montanide™ ISA 206 oil adjuvant. Five weeks post-immunization, DEV-specific SN antibody titers were significantly increased and reached to the peak level with a mean titer of 32, 128 and 256 in guinea pig, rabbit and goat sera, respectively. The globulin fraction of the prepared antisera was successfully precipitated with ammonium sulphate and then fluorescein-conjugated. The application of direct fluorescent antibody technique test was carried out on infected Vero cells with DEV on cover slips, revealed that positive reactions were obtained with guinea pig, rabbit and goat conjugates up to a dilution of 10-4, 10-5 and 10-6respectively. These findings clearly indicate that fluorescein-conjugated polyclonal antibodies developed in the present study can be used for accurate and precise diagnosis of DEV.