Publicação
Determination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human blood
| Resumo: | Nosocomial infections are a worldwide concern due to their impact on patients’ health and costs to the health care system. The majority of these infections are associated with the use of indwelling medical devices, which serve as scaffold for biofilm formation by bacteria or other microorganisms. Due to its remarkable capability to form biofilms on medical devices, Staphylococcus epidermidis, a commensal bacterium of healthy human skin and mucosae, has emerged as one of major causes of medical devices-associated infections, being particularly associated with vascular catheters. As a consequence, S. epidermidis biofilms are frequently associated with the emergence of bloodstream infections. Nevertheless, the interplay between S. epidermidis biofilms and human blood is poorly understood. Recently it was reported that S. epidermidis biofilms increase the transcription of genes associated with iron utilization when in contact with human blood. Iron is an important element for bacterial growth and low free-iron environments, like human blood, may be detrimental. Hence, in order to determine the importance of iron utilization for S. epidermidis, we have assessed the influence of different iron concentrations on the bacterium growth rate and biofilm formation capacity. In addition, the susceptibility of S. epidermidis biofilms to humans’ blood bactericidal activity and the quantification of the transcription of genes involved in iron detoxification (hssR and hrtA genes) were also addressed. The results obtained showed that the increasing iron concentrations tested had no significantly effect on S. epidermidis growth rate. In contrast, two of the four strains used showed increased biofilm formation capacity in the presence of high concentration of iron (500 μM FeCl3). Interestingly, 32 to 73% of the biofilm cells were able to survive the exposure to human blood. Nevertheless, the transcription of hssR gene was only found significantly increased in one of the strains used (clinical isolate PT11003). Although it was not possible to detect the hrtA gene, it is probably being transcribed since the activation of the hrtAB operon is hssR-dependent. In the future, iron-deprivation experiments should be performed in order to better understand iron utilization in S. epidermidis biofilms. |
|---|---|
| Autores principais: | Soares, Pedro Miguel Oliveira |
| Assunto: | Staphylococcus epidermidis Biofilms Human blood Iron Gene expression Ferro Sangue humano Expressão genética Engenharia e Tecnologia::Biotecnologia Industrial |
| Ano: | 2015 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| _version_ | 1867439268895391744 |
|---|---|
| author | Soares, Pedro Miguel Oliveira |
| author_facet | Soares, Pedro Miguel Oliveira |
| author_role | author |
| contributor_name_str_mv | Cerca, Nuno França, Ângela Maria Oliveira Sousa RepositóriUM - Universidade do Minho |
| country_str | PT |
| creators_json_txt | [{\"Person.name\":\"Soares, Pedro Miguel Oliveira\"}] |
| datacite.contributors.contributor.contributorName.fl_str_mv | Cerca, Nuno França, Ângela Maria Oliveira Sousa RepositóriUM - Universidade do Minho |
| datacite.creators.creator.creatorName.fl_str_mv | Soares, Pedro Miguel Oliveira |
| datacite.date.Accepted.fl_str_mv | 2015-01-01T00:00:00Z |
| datacite.rights.fl_str_mv | http://purl.org/coar/access_right/c_abf2 |
| datacite.subjects.subject.fl_str_mv | Staphylococcus epidermidis Biofilms Human blood Iron Gene expression Ferro Sangue humano Expressão genética Engenharia e Tecnologia::Biotecnologia Industrial |
| datacite.titles.title.fl_str_mv | Determination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human blood Determinação da importância da aquisição de ferro para a sobrevivência de biofilmes de Staphylococcus epidermidis em contacto com sangue humano |
| dc.contributor.none.fl_str_mv | Cerca, Nuno França, Ângela Maria Oliveira Sousa RepositóriUM - Universidade do Minho |
| dc.creator.none.fl_str_mv | Soares, Pedro Miguel Oliveira |
| dc.date.Accepted.fl_str_mv | 2015-01-01T00:00:00Z |
| dc.format.none.fl_str_mv | application/pdf |
| dc.identifier.none.fl_str_mv | https://hdl.handle.net/1822/41435 |
| dc.language.none.fl_str_mv | eng |
| dc.rights.none.fl_str_mv | http://purl.org/coar/access_right/c_abf2 |
| dc.subject.none.fl_str_mv | Staphylococcus epidermidis Biofilms Human blood Iron Gene expression Ferro Sangue humano Expressão genética Engenharia e Tecnologia::Biotecnologia Industrial |
| dc.title.fl_str_mv | Determination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human blood Determinação da importância da aquisição de ferro para a sobrevivência de biofilmes de Staphylococcus epidermidis em contacto com sangue humano |
| dc.type.none.fl_str_mv | http://purl.org/coar/resource_type/c_bdcc |
| description | Nosocomial infections are a worldwide concern due to their impact on patients’ health and costs to the health care system. The majority of these infections are associated with the use of indwelling medical devices, which serve as scaffold for biofilm formation by bacteria or other microorganisms. Due to its remarkable capability to form biofilms on medical devices, Staphylococcus epidermidis, a commensal bacterium of healthy human skin and mucosae, has emerged as one of major causes of medical devices-associated infections, being particularly associated with vascular catheters. As a consequence, S. epidermidis biofilms are frequently associated with the emergence of bloodstream infections. Nevertheless, the interplay between S. epidermidis biofilms and human blood is poorly understood. Recently it was reported that S. epidermidis biofilms increase the transcription of genes associated with iron utilization when in contact with human blood. Iron is an important element for bacterial growth and low free-iron environments, like human blood, may be detrimental. Hence, in order to determine the importance of iron utilization for S. epidermidis, we have assessed the influence of different iron concentrations on the bacterium growth rate and biofilm formation capacity. In addition, the susceptibility of S. epidermidis biofilms to humans’ blood bactericidal activity and the quantification of the transcription of genes involved in iron detoxification (hssR and hrtA genes) were also addressed. The results obtained showed that the increasing iron concentrations tested had no significantly effect on S. epidermidis growth rate. In contrast, two of the four strains used showed increased biofilm formation capacity in the presence of high concentration of iron (500 μM FeCl3). Interestingly, 32 to 73% of the biofilm cells were able to survive the exposure to human blood. Nevertheless, the transcription of hssR gene was only found significantly increased in one of the strains used (clinical isolate PT11003). Although it was not possible to detect the hrtA gene, it is probably being transcribed since the activation of the hrtAB operon is hssR-dependent. In the future, iron-deprivation experiments should be performed in order to better understand iron utilization in S. epidermidis biofilms. |
| dirty | 0 |
| eu_rights_str_mv | openAccess |
| format | masterThesis |
| fulltext.url.fl_str_mv | https://repositorium.uminho.pt/bitstreams/276b2b7a-136f-4be7-b1d0-c61106abe4f6/download |
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| identifier.url.fl_str_mv | https://hdl.handle.net/1822/41435 |
| instacron_str | repositorium |
| institution | Universidade do Minho |
| instname_str | Universidade do Minho |
| language | eng |
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| network_name_str | RepositóriUM - Universidade do Minho |
| oai_identifier_str | oai:repositorium.uminho.pt:1822/41435 |
| organization_str_mv | urn:organizationAcronym:repositorium |
| person_str_mv | Soares, Pedro Miguel Oliveira |
| publishDate | 2015 |
| reponame_str | RepositóriUM - Universidade do Minho |
| repository_id_str | urn:repositoryAcronym:rum |
| service_str_mv | urn:repositoryAcronym:rum |
| spelling | engporNosocomial infections are a worldwide concern due to their impact on patients’ health and costs to the health care system. The majority of these infections are associated with the use of indwelling medical devices, which serve as scaffold for biofilm formation by bacteria or other microorganisms. Due to its remarkable capability to form biofilms on medical devices, Staphylococcus epidermidis, a commensal bacterium of healthy human skin and mucosae, has emerged as one of major causes of medical devices-associated infections, being particularly associated with vascular catheters. As a consequence, S. epidermidis biofilms are frequently associated with the emergence of bloodstream infections. Nevertheless, the interplay between S. epidermidis biofilms and human blood is poorly understood. Recently it was reported that S. epidermidis biofilms increase the transcription of genes associated with iron utilization when in contact with human blood. Iron is an important element for bacterial growth and low free-iron environments, like human blood, may be detrimental. Hence, in order to determine the importance of iron utilization for S. epidermidis, we have assessed the influence of different iron concentrations on the bacterium growth rate and biofilm formation capacity. In addition, the susceptibility of S. epidermidis biofilms to humans’ blood bactericidal activity and the quantification of the transcription of genes involved in iron detoxification (hssR and hrtA genes) were also addressed. The results obtained showed that the increasing iron concentrations tested had no significantly effect on S. epidermidis growth rate. In contrast, two of the four strains used showed increased biofilm formation capacity in the presence of high concentration of iron (500 μM FeCl3). Interestingly, 32 to 73% of the biofilm cells were able to survive the exposure to human blood. Nevertheless, the transcription of hssR gene was only found significantly increased in one of the strains used (clinical isolate PT11003). Although it was not possible to detect the hrtA gene, it is probably being transcribed since the activation of the hrtAB operon is hssR-dependent. In the future, iron-deprivation experiments should be performed in order to better understand iron utilization in S. epidermidis biofilms.application/pdfporDetermination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human bloodAlternativeTitleporDeterminação da importância da aquisição de ferro para a sobrevivência de biofilmes de Staphylococcus epidermidis em contacto com sangue humanoSoares, Pedro Miguel OliveiraCerca, NunoFrança, Ângela Maria Oliveira SousaHostingInstitutionOrganizationalRepositóriUM - Universidade do Minhoe-mailmailto:repositorium@usdb.uminho.ptrepositorium@usdb.uminho.pt201520152015-01-01T00:00:00ZHandlehttps://hdl.handle.net/1822/41435http://purl.org/coar/access_right/c_abf2open accessStaphylococcus epidermidisBiofilmsHuman bloodIronGene expressionFerroSangue humanoExpressão genéticahttp://www.oecd.org/science/inno/38235147.pdfFields of Science and Technology (FOS)Engenharia e Tecnologia::Biotecnologia Industrial964315 bytesliteraturehttp://purl.org/coar/resource_type/c_bdccmaster thesishttp://purl.org/coar/access_right/c_abf2application/pdffulltexthttps://repositorium.uminho.pt/bitstreams/276b2b7a-136f-4be7-b1d0-c61106abe4f6/download |
| spellingShingle | Determination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human blood Soares, Pedro Miguel Oliveira Staphylococcus epidermidis Biofilms Human blood Iron Gene expression Ferro Sangue humano Expressão genética Engenharia e Tecnologia::Biotecnologia Industrial |
| status | SINGLETON |
| subject.fl_str_mv | Staphylococcus epidermidis Biofilms Human blood Iron Gene expression Ferro Sangue humano Expressão genética |
| subject.other.fl_str_mv | Engenharia e Tecnologia::Biotecnologia Industrial |
| title | Determination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human blood |
| title_full | Determination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human blood |
| title_fullStr | Determination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human blood |
| title_full_unstemmed | Determination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human blood |
| title_short | Determination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human blood |
| title_sort | Determination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human blood |
| topic | Staphylococcus epidermidis Biofilms Human blood Iron Gene expression Ferro Sangue humano Expressão genética Engenharia e Tecnologia::Biotecnologia Industrial |
| topic_facet | Staphylococcus epidermidis Biofilms Human blood Iron Gene expression Ferro Sangue humano Expressão genética Engenharia e Tecnologia::Biotecnologia Industrial |
| url | https://hdl.handle.net/1822/41435 |
| visible | 1 |