Genomic and Virulence Profiling of Erysipelothrix rhusiopathiae Isolated from Widespread Muskox Mortalities in Arctic Archipelago

Seru, Lakshmi Vineesha

Genomic and Virulence Profiling of Erysipelothrix rhusiopathiae Isolated from Widespread Muskox Mortalities in Arctic Archipelago

dc.contributor.advisor	Niu, Dongyan
dc.contributor.advisor	Kutz, Susan
dc.contributor.author	Seru, Lakshmi Vineesha
dc.contributor.committeemember	Mohamed, Faizal Abdul Careem
dc.contributor.committeemember	Forde, Taya L
dc.date	2023-06
dc.date.accessioned	2023-04-26T17:41:37Z
dc.date.available	2023-04-26T17:41:37Z
dc.date.issued	2023-04-21
dc.description.abstract	Muskoxen are an important food and economic resource for the indigenous people in the Canadian Arctic; however, in recent years this species has experienced substantial disease-related population declines. A single strain (‘Arctic clone’) of Erysipelothrix rhusiopathiae was associated with mass mortalities of muskoxen on Banks and Victoria Islands in 2010-2013, and various wild species on Prince Patrick Island in 2017. In 2021, an outbreak of E. rhusiopathiae was reported for the first time in muskoxen on Ellesmere Island. The predominance of the Arctic clone in the Arctic raises the question of virulence of this lineage. Objectives of this study were to characterize E. rhusiopathiae isolates from Ellesmere Island and identify amino acid sequence variations among 17 virulence genes, pathogenicity islands and prophages among 28 Arctic clone and 31 other closely related E. rhusiopathiae genomes. In addition, unique genetic contents of the Arctic clone that may encode virulence traits were determined via pan-genome wide association studies. Comparison of virulence gene sequences among 59 E. rhusiopathiae genomes offered insights into amino acid variations unique to the Arctic clone. I found that 16 of 17 virulence genes investigated were present and 4 of 17 were highly conserved among all the genomes. Putative virulence gene sequences of adhesin, rhusiopathiae surface protein-A, choline binding protein-B and leucine rich repeat protein had amino acid sequence variants unique to the Arctic clone. These genes encoded proteins that help E. rhusiopathiae to attach to the host endothelial cells and form biofilms. Characterizing pathogenicity islands revealed a novel finding of 12/28 Arctic clone isolates harbouring toxin-B. Toxin-B is an exotoxin produced by Clostridiodes difficile and causes pathogenesis via cytolysis. None of the prophages harboured virulence genes. The core genome alignment of 59 E. rhusiopathiae whole genomes provided evidence that the Arctic clone might be associated with the mortality on Ellesmere Island. The newly isolated E. rhusiopathiae belong to the Arctic clone, which was found to contain unique amino acid sequences for known virulence genes. The Arctic clone may have gained new virulence traits via mobile genetic elements mediated.
dc.identifier.citation	Seru, L. V. (2023). Genomic and virulence profiling of Erysipelothrix rhusiopathiae isolated from widespread muskox mortalities in Arctic Archipelago (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.uri	http://hdl.handle.net/1880/116107
dc.identifier.uri	https://dx.doi.org/10.11575/PRISM/dspace/40953
dc.language.iso	en
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary
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.
dc.subject	Arctic
dc.subject	muskoxen
dc.subject	mortality
dc.subject	Erysipelothrix rhusiopathiae
dc.subject	virulence genes
dc.subject	pathogenicity islands
dc.subject	prophages
dc.subject	pan-genome wide association studies
dc.subject.classification	Veterinary Science
dc.title	Genomic and Virulence Profiling of Erysipelothrix rhusiopathiae Isolated from Widespread Muskox Mortalities in Arctic Archipelago
dc.type	master thesis
thesis.degree.discipline	Veterinary Medical Sciences
thesis.degree.grantor	University of Calgary
thesis.degree.name	Master of Science (MSc)
ucalgary.thesis.accesssetbystudent	I require a thesis withhold – I need to delay the release of my thesis due to a patent application, and other reasons outlined in the link above. I have/will need to submit a thesis withhold application.