ResearchPad - avian-pathology https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Pathological and virological analysis of concurrent disease of chicken anemia virus infection and infectious bronchitis in Japanese native chicks]]> https://www.researchpad.co/article/N005c68e5-8529-4af6-a7e1-b1cddf141fda A concurrent infection of chicken anemia virus (CAV) and infectious bronchitis virus (IBV) was detected in Japanese native chicks in 2017, in which a high mortality rate (97.7%) was recorded in a small flock of 130 chicks exhibiting poor growth. Histological examination revealed that the affected chicks exhibited two different pathological entities: one was severe hematopoietic and lymphocytic depletion with abnormally large cells containing intranuclear inclusion bodies of CAV, whereas the other was renal tubular necrosis due to IBV infection. Immunohistochemistry detected CAV antigens in the bone marrow, liver, and spleen as well as IBV antigens in the kidneys, trachea, and air sacs. CAV was isolated from the liver sample of the chicks, and the isolated strain was designated as CAV/Japan/HS1/17. A phylogenetic analysis of the CAV VP1 gene revealed that CAV/Japan/HS1/17 is genetically similar to Chinese strains collected from 2014 to 2016. An experimental infection was performed using CAV/Japan/HS1/17 and specific-pathogen-free chicks to determine the pathogenicity of CAV/Japan/HS1/17. The isolate caused 100% anemia and 70% mortality to chicks inoculated at one day old, 80% of chicks inoculated at seven days old also developed anemia, and 10% died from CAV infection. These results suggest that the unusually high mortality in Japanese native chicks can be attributed to dual infection with both CAV and IBV. The results of the experimental infection suggest that CAV/Japan/HS1/17 has a pathogenic potential to specific-pathogen-free chicks and a relatively higher pathogenicity than previous Japanese CAV strains.

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<![CDATA[Change of pathotype and phylogenetic analysis of infectious bronchitis virus detected in Kagoshima prefecture, Japan]]> https://www.researchpad.co/article/Ncf024d8e-30ca-490e-8c96-e2b294f293ca Infectious bronchitis (IB) is a highly contagious disease in chickens, induced by IB virus (IBV) infection. The pathotype and S1 genotype of IBV field strain that was detected from 2008 to 2018 were investigated in Kagoshima prefecture, Japan. The frequency of cases that the renal lesion characteristic of IBV infection was histopathologically confirmed was significantly higher from 2014 to 2018 than from 2008 to 2009, suggesting the altered pathotype of IBV. Of 7 genotypes (JP-I, JP-II, JP-III, JP-IV, Mass, Gray, and 4/91) that have been detected in Japan, 6 genotypes except for JP-II were detected since 2008 and it appeared that the JP-III and JP-I have been predominant. The JP-IV with different antigenicity from other genotypes was detected since 2009.

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