Staphylococcus aureus: the host-organism relationship
<p><em>Staphylococcus aureus</em> is a worldwide leading cause of skin and soft tissue, bone and joint, and bloodstream infection. Despite this, <em>S. aureus</em> is also a harmless commensal in about one third of the population, although carriage is a risk factor for...
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| Format: | Abschlussarbeit |
| Sprache: | English |
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2011
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| _version_ | 1826302589078077440 |
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| author | Miller, R Ruth Miller |
| author2 | Crook, D |
| author_facet | Crook, D Miller, R Ruth Miller |
| author_sort | Miller, R |
| collection | OXFORD |
| description | <p><em>Staphylococcus aureus</em> is a worldwide leading cause of skin and soft tissue, bone and joint, and bloodstream infection. Despite this, <em>S. aureus</em> is also a harmless commensal in about one third of the population, although carriage is a risk factor for subsequent disease. <em>S. aureus</em> has evolved resistance to several antibiotics, including meticillin, resulting in meticillin-resistant <em>S. aureus</em> (MRSA), which in the UK largely consists of two epidemic lineages. In spite of much research, substantial aspects of the epidemiology and biology of <em>S. aureus</em> are still poorly understood.</p><p>In investigating the <em>S. aureus</em> host-organism relationship, this thesis has three aims. To explore the interface between community and hospital-acquired <em>S. aureus</em>; to investigate the carriage dynamics of <em>S. aureus</em> in the community; and to use population genetic methods to study epidemic hospital associated <em>S. aureus</em> lineages.</p><p>Case-control studies comparing hospital and community-acquired MRSA revealed that the majority of UK MRSA remains healthcare associated, with community-acquired MRSA reliably identified in only 0.2% of individuals. However, an additional 0.2% of individuals also carried "feral" MRSA with molecular characteristics identical to hospital-associated strains, but in hosts with no healthcare risk factors. To further investigate <em>S. aureus</em> carriage dynamics in the community, a carriage study was designed to collect detailed host factor information and correlate this with <em>S. aureus</em> carriage over time. In the study 32% of participants carried <em>S. aureus</em> of which the majority carried for over one year. Younger age was associated with transient carriage, including S. aureus acquisition in individuals who were initially negative. Finally, whole-genome sequencing of two epidemic <em>S. aureus</em> lineages indicated rapid clonal expansion of MRSA and clear geographic and temporal genetic structure. One particularly closely related cluster of strains may provide a genetic explanation for an MRSA outbreak in Brighton.</p> |
| first_indexed | 2024-03-07T05:49:52Z |
| format | Thesis |
| id | oxford-uuid:e87e8eb4-65f4-47f4-a836-c68ba79259df |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T05:49:52Z |
| publishDate | 2011 |
| record_format | dspace |
| spelling | oxford-uuid:e87e8eb4-65f4-47f4-a836-c68ba79259df2022-03-27T10:47:09ZStaphylococcus aureus: the host-organism relationshipThesishttp://purl.org/coar/resource_type/c_db06uuid:e87e8eb4-65f4-47f4-a836-c68ba79259dfEpidemiologyInfectious diseasesMedical SciencesGenetics (medical sciences)English2011Miller, RRuth MillerCrook, DBowden, R<p><em>Staphylococcus aureus</em> is a worldwide leading cause of skin and soft tissue, bone and joint, and bloodstream infection. Despite this, <em>S. aureus</em> is also a harmless commensal in about one third of the population, although carriage is a risk factor for subsequent disease. <em>S. aureus</em> has evolved resistance to several antibiotics, including meticillin, resulting in meticillin-resistant <em>S. aureus</em> (MRSA), which in the UK largely consists of two epidemic lineages. In spite of much research, substantial aspects of the epidemiology and biology of <em>S. aureus</em> are still poorly understood.</p><p>In investigating the <em>S. aureus</em> host-organism relationship, this thesis has three aims. To explore the interface between community and hospital-acquired <em>S. aureus</em>; to investigate the carriage dynamics of <em>S. aureus</em> in the community; and to use population genetic methods to study epidemic hospital associated <em>S. aureus</em> lineages.</p><p>Case-control studies comparing hospital and community-acquired MRSA revealed that the majority of UK MRSA remains healthcare associated, with community-acquired MRSA reliably identified in only 0.2% of individuals. However, an additional 0.2% of individuals also carried "feral" MRSA with molecular characteristics identical to hospital-associated strains, but in hosts with no healthcare risk factors. To further investigate <em>S. aureus</em> carriage dynamics in the community, a carriage study was designed to collect detailed host factor information and correlate this with <em>S. aureus</em> carriage over time. In the study 32% of participants carried <em>S. aureus</em> of which the majority carried for over one year. Younger age was associated with transient carriage, including S. aureus acquisition in individuals who were initially negative. Finally, whole-genome sequencing of two epidemic <em>S. aureus</em> lineages indicated rapid clonal expansion of MRSA and clear geographic and temporal genetic structure. One particularly closely related cluster of strains may provide a genetic explanation for an MRSA outbreak in Brighton.</p> |
| spellingShingle | Epidemiology Infectious diseases Medical Sciences Genetics (medical sciences) Miller, R Ruth Miller Staphylococcus aureus: the host-organism relationship |
| title | Staphylococcus aureus: the host-organism relationship |
| title_full | Staphylococcus aureus: the host-organism relationship |
| title_fullStr | Staphylococcus aureus: the host-organism relationship |
| title_full_unstemmed | Staphylococcus aureus: the host-organism relationship |
| title_short | Staphylococcus aureus: the host-organism relationship |
| title_sort | staphylococcus aureus the host organism relationship |
| topic | Epidemiology Infectious diseases Medical Sciences Genetics (medical sciences) |
| work_keys_str_mv | AT millerr staphylococcusaureusthehostorganismrelationship AT ruthmiller staphylococcusaureusthehostorganismrelationship |