Pathogenesis of Newcastle Disease in Vaccinated Chickens: Pathogenicity of Isolated Virus and Vaccine Effect on Challenge of Its Virus
| Autor: | Toshiki Nakamura, Masaji Mase, Kunitoshi Imai, Mitsuru Ito, Manabu Yamada, Kikuyasu Nakamura, Yu Yamamoto |
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| Rok vydání: | 2014 |
| Předmět: |
vaccinated chicken
animal structures Necrosis Newcastle Disease Newcastle disease virus Spleen Chick Embryo Newcastle disease Virus Disease Outbreaks Microbiology Tracheitis medicine Animals Bursa of Fabricius specific-pathogen-free chicken Full Paper Virulence General Veterinary biology pathogenesis Vaccination Viral Vaccines Hemagglutination Inhibition Tests medicine.disease biology.organism_classification Immunohistochemistry Virology Specific Pathogen-Free Organisms medicine.anatomical_structure Avian Pathology medicine.symptom Chickens Encephalitis |
| Zdroj: | The Journal of Veterinary Medical Science |
| ISSN: | 1347-7439 0916-7250 |
| DOI: | 10.1292/jvms.13-0284 |
| Popis: | The pathogenicity of Newcastle disease (ND) virus, isolated from ND outbreak in vaccinated chickens, was evaluated through experiments. The pathogenicity indexes (mean death time (MDT); 58 hr, intracerebral pathogenicity index (ICPI); 1.7 and intravenous pathogenicity index (IVPI); 2.51) indicated that the ND virus was velogenic. The ND virus caused lymphocytic necrosis in the spleen with fibrinous exudation and proliferation of macrophages, sinusoidal fibrin exudation in the liver, proliferation of macrophages in the lung, lymphocytic necrosis and depletion in the bursa of Fabricius, cecal tonsils and thymus, necrosis of bone marrow, tracheitis, conjunctivitis and necrosis of feather epithelial cells in specific-pathogen-free chickens. Immunohistochemically, ND virus antigens were seen in the lesions mentioned above. The ND virus could not induce the encephalitis and pancreatitis that were observed in the natural case of ND in vaccinated chickens. There was no clinical disease in vaccinated chickens after the challenge of the ND virus. In diluted ND vaccine experiments, chickens vaccinated with a high dilution of vaccine and then challenged with the ND virus showed clinical sign and mortality with pancreatic focal necrosis. Vaccine diluted with fresh tap water had no effect on protection against the challenge of the ND virus. This study suggests that improper vaccination may be involved in outbreaks of ND in vaccinated chickens. |
| Databáze: | OpenAIRE |
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