Properties of avian reoviruses isolated from chickens in Poland

One hundred and seventy-six samples collected from internal organs of sick birds and 40 samples taken from healthy birds were used for virus isolation. The isolation was carried out on SPF chicken embryos by inoculating them into the yolk sac with the material prepared by generally accepted methods. Three passages were performed. The presence of viral antigen was detected by the agar gel precipitation test using positive standard serum against reovirus strain S1133. Viral antigen was found in 79 samples (36.6%). Reoviruses were most often found in the bursa of Fabricius (in 61.7% of samples), liver (56.0%) and small intestine (36.8%). No virus was detected in samples collected from the: caecal tonsils and trachea. The examined strains multiplied in embryo membranes and lymphatic organs of embryos inducing pathological lesions and death.