The influence of non-inhibitory concentrations of purified pyocin S2 on Pseudomonas aeruginosa isolates

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dc.contributor.advisorStorey, Douglas
dc.contributor.authorMehina, Nabiha
dc.contributor.committeememberStorey, Douglas
dc.contributor.committeememberDeVinney, Rebekah
dc.contributor.committeememberParkins, Michael
dc.contributor.committeememberHarrison, Joe
dc.date2021-06
dc.date.accessioned2021-05-03T20:09:29Z
dc.date.available2021-05-03T20:09:29Z
dc.date.issued2021-04-27
dc.description.abstractPseudomonas aeruginosa is an opportunistic pathogen whose impacts are primarily in clinical settings. It is possible for multiple P. aeruginosa strains to be involved in an infection and each strain can diverge into many morphotypes. Intraspecies interactions between strains and morphotypes leads to a complex environment involving both beneficial and antagonistic interactions. S-type pyocins are bacteriocin proteins produced by P. aeruginosa that can inhibit closely related strains. Previously, we observed a P. aeruginosa isolate using S-type pyocins to decrease the virulence of other isolates in a Drosophila melanogaster model. We have reason to believe that this decrease in virulence may not only be because of the direct inhibition of the target isolates but additionally from a reduction in their virulence factor production. As a result, we hypothesized that P. aeruginosa isolates use S- pyocins to influence the overall virulence of microbial communities by decreasing the virulence factor production of target bacteria. In the current study, we purified a DNase S-type pyocin, S2, and used a variety of virulence assays to show that subinhibitory concentrations of this pyocin alter the virulence factor production of target P. aeruginosa isolates. In doing so, we also demonstrated that the effects of S2 on virulence factor production can vary for different strains. We further explored the interactions between S2 and target bacteria by demonstrating how one isolate was able to gain resistance towards S2. Using genetic sequencing, we identified mutations that treatment with S2 is selecting for which may account for this resistance and explored how these changes may explain the altered virulence factor production displayed by this isolate. From the results of this work, we shed new light upon the reactions of surrounding strains to S2 production and proposed a potential novel mechanism of resistance against this pyocin.en_US
dc.identifier.citationMehina, N. (2021). The influence of non-inhibitory concentrations of purified pyocin S2 on Pseudomonas aeruginosa isolates (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.en_US
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/38808
dc.identifier.urihttp://hdl.handle.net/1880/113344
dc.language.isoengen_US
dc.publisher.facultyScienceen_US
dc.publisher.institutionUniversity of Calgaryen
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.en_US
dc.subjectScienceen_US
dc.subjectMicrobiologyen_US
dc.subjectMolecularen_US
dc.subjectBacteriaen_US
dc.subjectPseudomonas aeruginosaen_US
dc.subjectVirulenceen_US
dc.subjectBacteriocinen_US
dc.subjectSubinhibitoryen_US
dc.subjectInterstrain interactionsen_US
dc.subjectPyocinen_US
dc.subjectPyocin S2en_US
dc.subjectResistanceen_US
dc.subject.classificationEducation--Sciencesen_US
dc.subject.classificationMicrobiologyen_US
dc.subject.classificationBiology--Molecularen_US
dc.titleThe influence of non-inhibitory concentrations of purified pyocin S2 on Pseudomonas aeruginosa isolatesen_US
dc.typemaster thesisen_US
thesis.degree.disciplineBiological Sciencesen_US
thesis.degree.grantorUniversity of Calgaryen_US
thesis.degree.nameMaster of Science (MSc)en_US
ucalgary.item.requestcopytrueen_US
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