Functional genomics of motile commensal intestinal bacteria

Neville, B. Anne

Please note that Appendix A & B are currently unavailable due to a restriction requested by the author.. Restriction lift date: 10000-01-01

Functional genomics of motile commensal intestinal bacteria

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dc.check.chapterOfThesis	Appendix A & B
dc.check.date	10000-01-01
dc.check.embargoformat	E-thesis on CORA only	en
dc.check.info	Please note that Appendix A & B are currently unavailable due to a restriction requested by the author.	en
dc.check.opt-out	Not applicable	en
dc.check.reason	This thesis contains third party copyrighted materials for which permission was not given for online use	en
dc.contributor.advisor	O'Toole, Paul W.	en
dc.contributor.advisor	Ross, R. Paul	en
dc.contributor.author	Neville, B. Anne
dc.contributor.funder	Irish Research Council for Science Engineering and Technology	en
dc.contributor.funder	Science Foundation Ireland	en
dc.date.accessioned	2013-07-30T08:18:57Z
dc.date.available	2013-07-30T08:18:57Z
dc.date.issued	2013
dc.date.submitted	2013
dc.description.abstract	Flagella confer upon bacteria the ability to move and are therefore organelles of significant bacteriological importance. The innate immune system has evolved to recognise flagellin, (the major protein component of the bacterial flagellar filament). Flagellate microbes can potentially stimulate the immune systems of mammals, and thus have significant immunomodulatory potential. The flagellum-biogenesis genotype and phenotype of Lactobacillus ruminis, an autochthonous intestinal commensal, was studied. The flagellum-biogenesis genotypes of motile enteric Eubacterium and Roseburia species were also investigated. Flagellin proteins were recovered from these commensal species, their amino-termini were sequenced and the proteins were found to be pro-inflammatory, as assessed by measurement of interleukin-8 (IL-8) secretion from human intestinal epithelial cell lines. For L. ruminis, this IL-8 secretion required signalling through Toll Like Receptor 5. A model for the regulation of flagellum-biogenesis in L. ruminis was inferred from transcriptomics data and bioinformatics analyses. Motility gene expression in this species may be under the control of a novel regulator, LRC_15730. Potential promoters for genes encoding flagellin proteins in the Eubacterium and Roseburia genomes analysed were inferred in silico. Relative abundances of the target Eubacterium and Roseburia species in the intestinal microbiota of 25 elderly individuals were determined. These species were found to be variably abundant in these individuals. Motility genes from these species were variably detected in the shotgun metagenome databases generated by the ELDERMET project. This suggested that a greater depth of sequencing, or improved evenness of sequencing, would be required to capture the full diversity of microbial functions for specific target or low abundance species in microbial communities by metagenomics. In summary, this thesis used a functional genomics approach to describe flagellum-mediated motility in selected Gram-positive commensal bacteria. The regulation of flagellum biosynthesis in these species, and the consequences of flagella expression from a host-interaction perspective were also considered.	en
dc.description.status	Not peer reviewed	en
dc.description.version	Accepted Version
dc.format.mimetype	application/pdf	en
dc.identifier.citation	Neville, B. A. 2013. Functional genomics of motile commensal intestinal bacteria. PhD Thesis, University College Cork.	en
dc.identifier.endpage	399
dc.identifier.uri	https://hdl.handle.net/10468/1201
dc.language.iso	en	en
dc.publisher	University College Cork	en
dc.rights	© 2013. Anne Neville	en
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/	en
dc.subject	Bacterial motility	en
dc.subject	Flagellin	en
dc.subject	Flagellum biogenesis	en
dc.subject	Pro-inflammatory response	en
dc.subject	Eubacterium	en
dc.subject	Roseburia	en
dc.subject	Lactobacillus	en
dc.subject.lcsh	Bacteria--Motility	en
dc.subject.lcsh	Flagella (Microbiology)	en
dc.thesis.opt-out	false
dc.title	Functional genomics of motile commensal intestinal bacteria	en
dc.type	Doctoral thesis	en
dc.type.qualificationlevel	Doctoral	en
dc.type.qualificationname	PhD (Science)	en
ucc.workflow.supervisor	cora@ucc.ie