Molecular characterization of economically important poultry viruses in western Canada
Date
2020-12-04
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Abstract
Avian Reovirus (ARV), Chicken Astrovirus (CAstV), and Hemorrhagic Enteritis Virus (HEV) are important enteric pathogens affecting poultry production around the world. These agents are the causative agents of Viral Arthritis (VA), White Chick Syndrome (WCS), and Hemorrhagic Enteritis (HE), respectively. In meat-type chickens, pathogenic strains of ARV can replicate in the joints leading to edema, inflammatory cell infiltrate, and fibrosis, which results in rupture of tendons. Similarly, pathogenic strains of CAstV can cause transient increase in mid to late embryo mortality, reducing hatchability between 4-68%, with some hatched birds exhibiting pale plumage; these “white chicks” (WCS) usually die within the first week of life. In turkeys, HEV infection has two presentations: 1) A clinical disease consisting on gastrointestinal hemorrhages, depression and immunosuppression (Clinical HE); and 2) subclinical infection, consisting in immunosuppression and causing economical losses due to secondary infections and plant condemnations. In recent years, these diseases have gained importance in western Canada as a result of the economic losses sustained from these infections in: a) feed conversion, b) high number of culls/first week mortality, c) secondary bacterial infections, c) processing plant condemnations; and d) costly disruptions to the Canadian Supply Management system. This thesis focuses on molecular characterization of ARV, CAstV, and HEV obtained either from clinical samples (ARV, CAstV), or from cases suspected to have subclinical infection (HEV) in poultry farms located in western Canada. The biological samples from chickens (ARV, CAStV) and turkeys (HEV) were collected from cases submitted for post-mortem examination and diagnosis to Poultry Health Services (PHS), a private poultry consulting firm, located in Airdrie, Alberta, western Canada. Further studies are required to assess the virulence of these isolates for understanding their impact in the western Canada Poultry Industry and for the implementation or enhancement of vaccination practices.
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Molecular characterization, Avian Reovirus, Viral Arthritis, Chicken Astrovirus, White Chick Syndrome, Turkey Hemorrhagic Enteritis Virus, Hemorrhagic Enteritis, mutation, recombination, poultry enteric viruses
Citation
Palomino-Tapia, V. A. (2020). Molecular characterization of economically important poultry viruses in western Canada (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.