Peptidoglycan recycling in the Gram-positive bacterium Staphylococcus aureus and its role in host-pathogen interaction

<p>Bacteria are enclosed by a peptidoglycan sacculus, an exoskeleton-like polymer composed of glycan strands cross-linked by short peptides. The sacculus surrounds the cell in a closed bag-like structure and forms the main structural component of the bacterial cell wall. As bacteria grow and d...

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Tác giả chính: Dorling, J
Tác giả khác: Ligoxygakis, P
Định dạng: Luận văn
Ngôn ngữ:English
Được phát hành: 2018
Những chủ đề:
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author Dorling, J
author2 Ligoxygakis, P
author_facet Ligoxygakis, P
Dorling, J
author_sort Dorling, J
collection OXFORD
description <p>Bacteria are enclosed by a peptidoglycan sacculus, an exoskeleton-like polymer composed of glycan strands cross-linked by short peptides. The sacculus surrounds the cell in a closed bag-like structure and forms the main structural component of the bacterial cell wall. As bacteria grow and divide, cell wall remodelling by peptidoglycan hydrolases results in the release of peptidoglycan fragments from the sacculus. In Gram-negative bacteria, these fragments are efficiently trapped and recycled. Gram-positive bacteria however shed large quantities of peptidoglycan fragments into the environment. For nearly five decades, Gram-positive bacteria were thus assumed not to recycle peptidoglycan and this process has remained enigmatic until recently. In this thesis, the occurrence and physiological role of peptidoglycan recycling in the Gram-positive pathogen <em>Staphylococcus aureus</em> was investigated. <em>S. aureus</em> is an important pathogen, and is becoming increasingly resistant to many antibiotics. Through bioinformatic and experimental means it was determined that <em>S. aureus</em> may potentially recycle components of peptidoglycan and novel peptidoglycan recycling components were identified and characterised. Though disruption of putative peptidoglycan recycling in <em>S. aureus</em> appears not affect growth or gross morphology of this bacterium, potential roles for peptidoglycan recycling in cell wall homeostasis and in virulence were identified. This is to my knowledge the first demonstration of a potential role of peptidoglycan recycling in either of these aspects of bacterial physiology in any Gram-positive bacterium. This is an important step forward in understanding the basic biology of Gram-positive bacteria, and in understanding the mechanisms of virulence in <em>S. aureus</em>. Future study of this process in <em>S. aureus</em> and other Gram-positive bacteria promises to reveal yet further facets of this process and its functions, potentially leading to the identification of novel therapeutic approaches to combat infections.</p>
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spelling oxford-uuid:3fc4f926-296d-43a1-bb45-af9f37a87d8d2024-12-07T16:35:58ZPeptidoglycan recycling in the Gram-positive bacterium Staphylococcus aureus and its role in host-pathogen interactionThesishttp://purl.org/coar/resource_type/c_db06uuid:3fc4f926-296d-43a1-bb45-af9f37a87d8dMicrobiologyMolecular BiologyBiologyBiochemistryImmunologyEnglishORA Deposit2018Dorling, JLigoxygakis, P<p>Bacteria are enclosed by a peptidoglycan sacculus, an exoskeleton-like polymer composed of glycan strands cross-linked by short peptides. The sacculus surrounds the cell in a closed bag-like structure and forms the main structural component of the bacterial cell wall. As bacteria grow and divide, cell wall remodelling by peptidoglycan hydrolases results in the release of peptidoglycan fragments from the sacculus. In Gram-negative bacteria, these fragments are efficiently trapped and recycled. Gram-positive bacteria however shed large quantities of peptidoglycan fragments into the environment. For nearly five decades, Gram-positive bacteria were thus assumed not to recycle peptidoglycan and this process has remained enigmatic until recently. In this thesis, the occurrence and physiological role of peptidoglycan recycling in the Gram-positive pathogen <em>Staphylococcus aureus</em> was investigated. <em>S. aureus</em> is an important pathogen, and is becoming increasingly resistant to many antibiotics. Through bioinformatic and experimental means it was determined that <em>S. aureus</em> may potentially recycle components of peptidoglycan and novel peptidoglycan recycling components were identified and characterised. Though disruption of putative peptidoglycan recycling in <em>S. aureus</em> appears not affect growth or gross morphology of this bacterium, potential roles for peptidoglycan recycling in cell wall homeostasis and in virulence were identified. This is to my knowledge the first demonstration of a potential role of peptidoglycan recycling in either of these aspects of bacterial physiology in any Gram-positive bacterium. This is an important step forward in understanding the basic biology of Gram-positive bacteria, and in understanding the mechanisms of virulence in <em>S. aureus</em>. Future study of this process in <em>S. aureus</em> and other Gram-positive bacteria promises to reveal yet further facets of this process and its functions, potentially leading to the identification of novel therapeutic approaches to combat infections.</p>
spellingShingle Microbiology
Molecular Biology
Biology
Biochemistry
Immunology
Dorling, J
Peptidoglycan recycling in the Gram-positive bacterium Staphylococcus aureus and its role in host-pathogen interaction
title Peptidoglycan recycling in the Gram-positive bacterium Staphylococcus aureus and its role in host-pathogen interaction
title_full Peptidoglycan recycling in the Gram-positive bacterium Staphylococcus aureus and its role in host-pathogen interaction
title_fullStr Peptidoglycan recycling in the Gram-positive bacterium Staphylococcus aureus and its role in host-pathogen interaction
title_full_unstemmed Peptidoglycan recycling in the Gram-positive bacterium Staphylococcus aureus and its role in host-pathogen interaction
title_short Peptidoglycan recycling in the Gram-positive bacterium Staphylococcus aureus and its role in host-pathogen interaction
title_sort peptidoglycan recycling in the gram positive bacterium staphylococcus aureus and its role in host pathogen interaction
topic Microbiology
Molecular Biology
Biology
Biochemistry
Immunology
work_keys_str_mv AT dorlingj peptidoglycanrecyclinginthegrampositivebacteriumstaphylococcusaureusanditsroleinhostpathogeninteraction