DEVELOPMENT AND APPLICATION OF AN IMMUNOHISTOCHEMICAL STAINING TECHNIQUE TO DETECT AVIAN POLYOMAVIRAL ANTIGEN IN TISSUE-SECTIONS

An immunohistochemical staining technique was developed to detect poly omaviral antigens of budgerigar fledgling disease in formalin-fixed ti ssue sections. This technique used an indirect avidin-biotin, alkaline phosphatase labeling system with a mixture of monoclonal antibodies d eveloped against the virus major capsid protein. The staining techniqu e was applied retrospectively to 24 avian accessions which were origin ally diagnosed as budgerigar fledgling disease or avian polyomavirus i nfection based on microscopic findings including typical intranuclear inclusions. Immunohistochemical staining resulted in positive reaction s in some tissues from 17 of 24 cases. The tissues most frequently con taining typical intranuclear inclusions or positive immunohistochemica l staining were the spleen, liver, and kidney. Neither of the 2 nonpsi ttacine cases was positive immunohistochemically. This technique may b e used either as a rapid test on routinely processed diagnostic sample s to confirm the presence of avian polyomavirus or for pathogenesis re search studies.