Serologic comparison of avian reovirus isolates using virus neutralization and an enzyme-linked immunosorbent assay

The serologic relatedness of six avian reovirus isolates (CO8, S1133, 81-5, 2408, 1733, and UMI 203) were determined using a virus-neutralization (VN) test and an enzyme-linked immunosorbent assay (ELISA). Six groups of 20 specific-pathogen-free broilers each were twice infected with one of the six isolates per group. Serum was reacted against each isolate in a beta VN test in chicken embryo kidney cells and against the S1133 virus in ELISA. Relatedness (R) values, determined by cross VN, revealed that all belonged to a single serotype. However, the CO8 isolate represented a major subtype difference compared with the other isolates. R values among the five other isolates indicated minor or no subtype differences. ELISA also showed major differences between the CO8 and the other isolates.