ABSTRACT
A total of 75 P. aeruginosa isolates were secured out of 280 samples from diseased chickens suffering from different respiratory manifestations. The isolates were characterized and serotyped. The most prevalent serotypes were O3 and O4. An inactivated bivalent P. aeruginosa vaccine was prepared from these serotypes. The inactivation was achieved through irradiation with Cobalt 60. The quality control analysis of the prepared irradiated vaccine indicated that it was safe and its use was not associated with any clinical distress. Application of ELISA for evaluation of humoral immune response developed against P. aeruginosa in the vaccinated chicken groups showed significant increase in antibody titers, which was influenced by the route of immunization. The protection rates post challenge reached 100%, 96% and 90% among the intramuscularly, subcutaneously and orally vaccinated chicken groups, respectively. Also, vaccination of egg laying hens with the prepared vaccine stimulated formation and concentration of P. aeruginosa. specific IgY in the egg yolk