{"id":{"repo_id":"cork","oai_identifier":"oai:cora.ucc.ie:10468/2771"},"canonical_url":"https://search.dev.ndltd.org/etd/cork/oai:cora.ucc.ie:10468/2771","repository":{"repo_id":"cork","name":"University College Cork","base_url":"https://cora.ucc.ie/server/oai/request"},"display":{"title":"An analysis of selected secretion systems of Pseudomonas species","abstract":"Direct secretion systems which deliver molecules from one cell to another have huge significance in shaping bacterial communities or in determining the outcome of bacterial associations with eukaryotic organisms. This work examines the roles of the Type III Secretion System (T3SS) and the Type VI Secretion System (T6SS) systems of Pseudomonas, a widespread genus including clinical pathogens and biocontrol strains. Bioinformatic analysis of T6SS phylogeny and associated gene content within Pseudomonas identified several T6SS phylogenetic groups, and linked T6SS components VgrG and Hcp encoded outside of T6SS gene loci with their cognate T6SS phylogenetic groups. Remarkably, such “orphan” vgrG and hcp genes were found to occur in diverse, horizontally transferred, operons often containing putative T6SS accessory components and effectors. The prevalence of a widespread superfamily of T6SS lipase effectors (Tle) was assessed in metagenomes from various environments. The abundance of the Tle superfamily and individual families varied between niches, suggesting there is niche specific selection and specialisation of Tle. Experimental work also discovered that P. fluorescens F113 uses the SPI-1 T3SS to avoid amoeboid grazing in mixed populations. This finding may represent a significant aspect of F113 rhizocompetence, and the rhizocompetence of other Rhizobacteria.","abstract_html":"Direct secretion systems which deliver molecules from one cell to another have huge significance in shaping bacterial communities or in determining the outcome of bacterial associations with eukaryotic organisms. This work examines the roles of the Type III Secretion System (T3SS) and the Type VI Secretion System (T6SS) systems of Pseudomonas, a widespread genus including clinical pathogens and biocontrol strains. Bioinformatic analysis of T6SS phylogeny and associated gene content within Pseudomonas identified several T6SS phylogenetic groups, and linked T6SS components VgrG and Hcp encoded outside of T6SS gene loci with their cognate T6SS phylogenetic groups. Remarkably, such “orphan” vgrG and hcp genes were found to occur in diverse, horizontally transferred, operons often containing putative T6SS accessory components and effectors. The prevalence of a widespread superfamily of T6SS lipase effectors (Tle) was assessed in metagenomes from various environments. The abundance of the Tle superfamily and individual families varied between niches, suggesting there is niche specific selection and specialisation of Tle. Experimental work also discovered that P. fluorescens F113 uses the SPI-1 T3SS to avoid amoeboid grazing in mixed populations. This finding may represent a significant aspect of F113 rhizocompetence, and the rhizocompetence of other Rhizobacteria.","abstract_has_math":false,"creators":["Egan, Michael Frank"],"institution":"University College Cork","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["O'Gara, Fergal"],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014","date_published":"2014","updated_at":"2026-07-24T01:46:08Z","subjects":["Pseudomonas","Type VI secretion system","Type III secretion system","Type VI lipase effectors","VgrG islands"],"languages":["en"],"rights":["© 2014, Michael Frank Egan."],"rights_urls":["http://creativecommons.org/licenses/by-nc-nd/3.0/"],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/10468/2771","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["O'Gara, Fergal"]},{"key":"dc:creator","label":"Author","values":["Egan, Michael Frank"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2016-06-22T09:22:40Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2016-06-22T09:22:40Z"]},{"key":"dc:date.issued","label":"Date","values":["2014"]},{"key":"dc:publisher","label":"Institution","values":["University College Cork"]},{"key":"dc:type","label":"Dc Type","values":["Doctoral thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["PhD (Science)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Pseudomonas","Type VI secretion system","Type III secretion system","Type VI lipase effectors","VgrG islands"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["© 2014, Michael Frank Egan."]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://creativecommons.org/licenses/by-nc-nd/3.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10468/2771"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Direct secretion systems which deliver molecules from one cell to another have huge significance in shaping bacterial communities or in determining the outcome of bacterial associations with eukaryotic organisms. This work examines the roles of the Type III Secretion System (T3SS) and the Type VI Secretion System (T6SS) systems of Pseudomonas, a widespread genus including clinical pathogens and biocontrol strains. Bioinformatic analysis of T6SS phylogeny and associated gene content within Pseudomonas identified several T6SS phylogenetic groups, and linked T6SS components VgrG and Hcp encoded outside of T6SS gene loci with their cognate T6SS phylogenetic groups. Remarkably, such “orphan” vgrG and hcp genes were found to occur in diverse, horizontally transferred, operons often containing putative T6SS accessory components and effectors. The prevalence of a widespread superfamily of T6SS lipase effectors (Tle) was assessed in metagenomes from various environments. The abundance of the Tle superfamily and individual families varied between niches, suggesting there is niche specific selection and specialisation of Tle. Experimental work also discovered that P. fluorescens F113 uses the SPI-1 T3SS to avoid amoeboid grazing in mixed populations. This finding may represent a significant aspect of F113 rhizocompetence, and the rhizocompetence of other Rhizobacteria."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["An analysis of selected secretion systems of Pseudomonas species"]}]}],"canonical_facts":{"dc:contributor.advisor":["O'Gara, Fergal"],"dc:creator":["Egan, Michael Frank"],"dc:date.accessioned":["2016-06-22T09:22:40Z"],"dc:date.available":["2016-06-22T09:22:40Z"],"dc:date.issued":["2014"],"dc:description.abstract":["Direct secretion systems which deliver molecules from one cell to another have huge significance in shaping bacterial communities or in determining the outcome of bacterial associations with eukaryotic organisms. This work examines the roles of the Type III Secretion System (T3SS) and the Type VI Secretion System (T6SS) systems of Pseudomonas, a widespread genus including clinical pathogens and biocontrol strains. Bioinformatic analysis of T6SS phylogeny and associated gene content within Pseudomonas identified several T6SS phylogenetic groups, and linked T6SS components VgrG and Hcp encoded outside of T6SS gene loci with their cognate T6SS phylogenetic groups. Remarkably, such “orphan” vgrG and hcp genes were found to occur in diverse, horizontally transferred, operons often containing putative T6SS accessory components and effectors. The prevalence of a widespread superfamily of T6SS lipase effectors (Tle) was assessed in metagenomes from various environments. The abundance of the Tle superfamily and individual families varied between niches, suggesting there is niche specific selection and specialisation of Tle. Experimental work also discovered that P. fluorescens F113 uses the SPI-1 T3SS to avoid amoeboid grazing in mixed populations. This finding may represent a significant aspect of F113 rhizocompetence, and the rhizocompetence of other Rhizobacteria."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["https://hdl.handle.net/10468/2771"],"dc:language.iso":["en"],"dc:publisher":["University College Cork"],"dc:rights":["© 2014, Michael Frank Egan."],"dc:rights.uri":["http://creativecommons.org/licenses/by-nc-nd/3.0/"],"dc:subject":["Pseudomonas","Type VI secretion system","Type III secretion system","Type VI lipase effectors","VgrG islands"],"dc:title":["An analysis of selected secretion systems of Pseudomonas species"],"dc:type":["Doctoral thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["PhD (Science)"]},"updated_at":"2026-07-24T01:46:08Z"}