Bacteriocins of bovine non-aureus staphylococci

Simple item page
atmire.migration.oldid6038
dc.contributor.advisorBarkema, Herman W.
dc.contributor.advisorDe Buck, Jeroen
dc.contributor.authorCarson, Domonique
dc.contributor.committeememberOrsel, Karsina
dc.contributor.committeememberCobo, Eduardo
dc.date.accessioned2017-09-22T14:42:37Z
dc.date.available2017-09-22T14:42:37Z
dc.date.issued2017
dc.date.submitted2017en
dc.description.abstractThe non-aureus staphylococci (NAS) species are among the most prevalent isolated from bovine milk and have been reported to inhibit major mastitis pathogens, likely by producing bacteriocins. This thesis is comprised of two sections, focusing on in vitro inhibition assays and in silico identification of bacteriocin gene clusters and bacteriocin resistance genes in NAS and Staphylococcus aureus, using isolates obtained from the Canadian Bovine Mastitis and Milk Quality Research Network. The first part determined the inhibitory capability of 441 bovine NAS isolates (comprising 25 species) against bovine S. aureus and human methicillin-resistant S. aureus (MRSA) and determined the presence of bacteriocin biosynthetic gene clusters in NAS whole genomes. Overall, 40 isolates from 9 species (S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. saprophyticus, S. sciuri, S. simulans, S. warneri, and S. xylosus) inhibited growth of S. aureus in vitro; of which, 23 isolates (from S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. simulans, and S. xylosus) also inhibited MRSA. 105 putative bacteriocin gene clusters encompassing 6 different subclasses (lanthipeptides, sactipeptides, lasso peptides, class IIa, class IIc, and class IId) in 95 whole genomes from 16 species were identified. The second part of the thesis determined the susceptibility of 139 bovine S. aureus isolates to a bacteriocin producing S. chromogenes isolate and identified and described the distribution of genes potentially associated with susceptibility and resistance in S. aureus whole genomes. Overall, 90 S. aureus isolates (65%) were resistant to inhibition by the S. chromogenes isolate. We identified 77 genes that were associated with an isolate being resistant. We also identified 76 genes that were associated with an isolate being susceptible to the S. chromogenes. Bacteriocin susceptibility and resistance seems to be linked to a large number of genes, the majority of which are annotated as hypothetical proteins and will need further assessment to determine their role in S. aureus susceptibility. Overall, bacteriocins may be a potential source of novel antimicrobials and this thesis represents the foundation to explore novel NAS bacteriocins.en_US
dc.identifier.citationCarson, D. (2017). Bacteriocins of bovine non-aureus staphylococci (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25092en_US
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/25092
dc.identifier.urihttp://hdl.handle.net/11023/4124
dc.language.isoeng
dc.publisher.facultyGraduate Studies
dc.publisher.facultyVeterinary Medicine
dc.publisher.institutionUniversity of Calgaryen
dc.publisher.placeCalgaryen
dc.rightsUniversity 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.subjectAgriculture
dc.subjectBioinformatics
dc.subjectMicrobiology
dc.subjectVeterinary Science
dc.subject.othermastitis
dc.subject.otherbovine
dc.subject.otherbacteriocin
dc.subject.otherstaphylococci
dc.titleBacteriocins of bovine non-aureus staphylococci
dc.typemaster thesis
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameMaster of Science (MSc)
ucalgary.item.requestcopytrue
Files
Collections
Open Theses and Dissertations