Infectious laryngotracheitis infection in chickens raised in Western Canada: Molecular characterization and vaccine efficacy studies

Barboza Solis, Catalina

Infectious laryngotracheitis infection in chickens raised in Western Canada: Molecular characterization and vaccine efficacy studies

dc.contributor.advisor	Abdul Careem, Faizal
dc.contributor.author	Barboza Solis, Catalina
dc.contributor.committeemember	van der Meer, Frank
dc.contributor.committeemember	Fonseca, Kevin
dc.date	2021-11
dc.date.accessioned	2021-08-05T18:43:23Z
dc.date.available	2021-08-05T18:43:23Z
dc.date.issued	2021-07-30
dc.description.abstract	Genomic surveillance of circulating infectious laryngotracheitis virus (ILTV) in specific geographical areas is vital for the control of the disease caused by ILTV, infectious laryngotracheitis (ILT). ILTV is endemic in backyard flocks in some Canadian provinces including Alberta (AB). Sporadic outbreaks of ILTV are reported throughout Canada in both commercial and non-commercial poultry flocks. However, there is a lack of information on the molecular nature of circulating ILTV strains associated with ILT in Canada. Vaccines are used for the control of ILT, and vaccination is employed only in certain provinces due to concerns of limitations of the currently available vaccines. In AB, only breeder flocks are vaccinated routinely in addition to a portion of the backyard flocks. Out of the two commercially available vaccines, the recombinant viral vector vaccines are considered the safest. This is due to their lack of bird-to-bird transmission and reversion to a virulent form. The first part of the thesis work was focussed on genotyping ILTV isolates linked to ILT clinical cases in AB and British Columbia (BC). Through partial sequencing of open reading frame (ORF) a and b using Sanger sequencing technology, we were able to genotype 27 ILTV isolates from AB and 5 ILTV isolates from BC. We demonstrated that the most common genotype causing ILT outbreaks in AB were chicken embryo origin (CEO) vaccine revertant ILTV strains and then, wild-type ILTV strains. In BC, we identified CEO vaccine and CEO revertant ILTV strains as cause of ILT outbreaks. The second part of this thesis was focussed on determining if recombinant herpesvirus of turkeys- laryngotracheitis (rHVT-LT) commercial vaccine could protect chickens from ILT induced by a wild-type ILTV strain isolated from AB. Our results showed that the rHVT-LT can decrease viral shedding though the oropharyngeal route. However, it did not mitigate clinical signs at the peak of the disease, and it failed to reduce viral replication in the feather tips. Overall, the work described in the thesis contributed to the knowledge on ILTV molecular epidemiology and vaccine-mediated control of ILT.	en_US
dc.identifier.citation	Barboza Solis, C. (2021). Infectious laryngotracheitis infection in chickens raised in Western Canada: Molecular characterization and vaccine efficacy studies (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/39074
dc.identifier.uri	http://hdl.handle.net/1880/113708
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 laryngotracheitis, Sanger sequencing, live attenuated vaccine, rHVT-LT, chicken, back yard poultry	en_US
dc.subject.classification	Veterinary Science	en_US
dc.subject.classification	Virology	en_US
dc.title	Infectious laryngotracheitis infection in chickens raised in Western Canada: Molecular characterization and vaccine efficacy studies	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