Pathogenesis of and, host responses to Canadian 4/91 infectious bronchitis virus infection in specific pathogen free chickens

Mohamed Najimudeen, Fathima Shahnas

Pathogenesis of and, host responses to Canadian 4/91 infectious bronchitis virus infection in specific pathogen free chickens

dc.contributor.advisor	Abdul Careem, Mohamed Faizal
dc.contributor.author	Mohamed Najimudeen, Fathima Shahnas
dc.contributor.committeemember	Cork, Susan
dc.contributor.committeemember	Van Marle, Giudo
dc.contributor.committeemember	van der Meer, Franciscus
dc.contributor.committeemember	Abdul Careem, Mohamed Faizal
dc.date	2021-11
dc.date.accessioned	2021-08-09T20:38:31Z
dc.date.available	2021-08-09T20:38:31Z
dc.date.issued	2021-07-30
dc.description.abstract	Infectious bronchitis (IB) is an economically important disease in chickens caused by infectious bronchitis virus (IBV), which is a coronavirus. The 4/91 strain of IBV is globally distributed with a broad tissue tropism. In Canada, the 4/91 IBV strain was first recorded in 2011 and was dominant until 2017 in Eastern Canadian poultry flocks. The affected flocks presented clinically with respiratory and egg production problems. Information is lacking on the pathogenesis of Canadian (CAN) 4/91 IBV and host responses to this virus in chickens. Thus, the objectives of the thesis research were to determine the impact of the CAN 4/91 IBV variant on egg production and quality and then, to investigate the nephropathogenicity and host responses mounted against this virus infection in specific pathogen-free (SPF) chickens. To investigate CAN 4/91 IBV infection in laying hens, 28-week-old hens were infected with CAN 4/91 IBV and compared with uninfected controls. The hens were monitored daily for egg production and quality and for other clinical signs. Oropharyngeal (OP) and cloacal (CL) swab samples were collected at predetermined time points. A subset of hens from each group were euthanized at 6 and 10 days post-infection (dpi). We observed that the CAN 4/91 IBV isolate has a very broad tissue tropism including the reproductive tract. However, it did not significantly affect egg production or egg quality with minor histological changes in the shell gland. The analysis of the kidneys showed histopathological lesions in infected animals and significant recruitment of T cells and macrophages. For investigation of pathogenicity of CAN 4/91 IBV in the respiratory tract and kidneys of young chickens, one-week-old, unsexed chickens were infected with CAN 4/91 IBV maintaining uninfected controls. The chickens were monitored daily for clinical signs. At 3, 7 and 10 dpi, 5 chickens from each group were euthanized. IBV replicated and induced histopathological lesions, upregulation of genes of proinflammatory mediators and significant recruitment of T cells and macrophages in lung and kidney tissues. Overall, our study contributed to the understanding of the pathogenesis of and host responses to CAN 4/91 IBV infection in SPF layer chickens.	en_US
dc.identifier.citation	Mohamed Najimudeen, F. S. (2021). Pathogenesis of and, host responses to Canadian 4/91 infectious bronchitis virus infection in specific pathogen free chickens (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/39084
dc.identifier.uri	http://hdl.handle.net/1880/113722
dc.language.iso	eng	en_US
dc.publisher.faculty	Veterinary Medicine	en_US
dc.publisher.institution	University of Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.	en_US
dc.subject	Infectious bronchitis virus, Pathogenesis, Immune responses	en_US
dc.subject.classification	Veterinary Science	en_US
dc.subject.classification	Virology	en_US
dc.subject.classification	Immunology	en_US
dc.title	Pathogenesis of and, host responses to Canadian 4/91 infectious bronchitis virus infection in specific pathogen free chickens	en_US
dc.type	master thesis	en_US
thesis.degree.discipline	Veterinary Medical Sciences	en_US
thesis.degree.grantor	University of Calgary	en_US
thesis.degree.name	Master of Science (MSc)	en_US
ucalgary.item.requestcopy	true	en_US