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Characterization and comparison of the pathogenicity of viscerotropic velogenic Newcastle disease virus isolates in Korea
2012
Kim, J.H., Seoul National University, Seoul, Republic of Korea | Sung, H.W., Kangwon National University, Chuncheon, Republic of Korea | Kim, I.H., Seoul National University, Seoul, Republic of Korea | Lee, E.K., Animal, Plant and Fisheries Quarantine and Inspection Agency, Anyang, Republic of Korea | Choi, K.S., Animal, Plant and Fisheries Quarantine and Inspection Agency, Anyang, Republic of Korea | King, Daniel Jack, Southeast Poultry Research Laboratory, USDA-ARS, Athens, GA, USA
A total of 18 Newcastle disease virus (NDV) isolates that were recovered from 1949 through 1997 were characterized and pathotyped. All viruses were highly virulent as determined by intracerebral pathogenicity indices greater-than or equal to 1.81 in day-old. These pathotypes are typical for viscerotropic velogenic NDV (VVNDV) pathotype viruses. Some differences were observed for the chicken red blood cell elution rate and thermostability of the hemagglutinin at 56℃. Three antigenic groups were identified by a hemagglutination-inhibition assay using NDV monoclonal antibodies. And the predominant gross lesions were as follows: discharge from the nasal cavity, tracheal mucus, petechial hemorrhage in the heart fat, kidney urates and hemorrhage with or without necrosis in the gastrointestinal tract. Severe hemorrhagic or necrotic lesions were also noted in the lymphoid organs and were localized primarily in the spleen and cecal tonsil. However, differences in the occurrence and frequency of the gross lesions were observed between the virus strains. Among them, NDV strains that induced neurological symptoms belonged only to genotype Ⅵ. This strain had spread throughout Korea during the late 1980s to the 1990s, which suggests that specific VVNDVs genotypes might result in neurological symptoms.
Show more [+] Less [-]Characterization of a pigeon paramyxovirus (PPMV-1) isolated from chickens in South Africa
2004
Abolnik, C. (Agricultural Research Council, Onderstepoort (South Africa). Onderstepoort Veterinary Research Inst.) | Horner, P. | Maharaj, R. | Viljoen, G.J.
