Identification and serological differentiation of several reovirus strains isolated from chickens with suspected malabsorption syndrome.

Five virus strains designated CO8, 43A, 45, 81-5, and 82-9 were isolated from the intestines of 3-to-6-week-old broilers showing signs and lesions consistent with malabsorption syndrome. The strains were identified as reoviruses based on their effect on chicken embryo kidney cells, morphology, chloroform, iododeoxyuridine and heat sensitivity, hemagglutination ability, pathogenicity in embryos, and replication cycle. Relatedness values, determined by cross-neutralization studies, revealed that the strains could be classified into three distinct serotypes. Two of the serotypes did not share antigenic relationship with strain S1133, which has been used in the field to vaccinate chickens against viral arthritis.