Publicação
Survival of Staphylococcus epidermidis biofilm-released cells in human blood and plasma
| Resumo: | Staphylococcus epidermidis colonizes healthy human skin and mucosa as a commensal microbe. It is an opportunistic pathogen, since it requires a major breach in the host innate defence. Also, this bacterial species has become one of the leading nosocomial pathogens, in particular medical devices-related infections such as intravascular catheters. Accordingly, S. epidermidis causes at least 22 % of bloodstream infections, detected in intensive care in the United Sates. The main factor that often sustains the commensal lifestyle of this bacteria is its remarkable capability to adhere to the surfaces of indwelling medical devices and subsequently form biofilms. Once a biofilm is completely developed, cells start to detach from the biofilm. The release of cells from biofilms plays a crucial role in spread of the infection, as they have been associated with acute infections such sepsis and devastating embolic events of endocarditis. However, despite its pathogenicity, the research regarding to the interaction between S. epidermidis biofilm-released cells (Brc) and human blood lies in an embryonic state. For a better understanding of the interaction between these cells and host immune system, Brc were characterized upon contact to human blood and plasma. Furthermore, virulence determinants were analyzed and its quantification performed by quantitative PCR. Our results revealed that S. epidermidis Brc display virulence potential. Interestingly, S. epidermidis Brc survival showed different responses between strains as well as donors. The transcriptome differences in response to immune cells between the strains studied enhance the particular characteristics inherent to each strain and, as a consequence, a particular behaviour developed when exposed to the host immune system. Thus, targeting the particular characteristics of Brc is important to prevent the severe acute infections associated with the release of cells from biofilms. In conclusion, the workflow described throughout this thesis provide an important contribution to the knowledge of the Brc, of this important nosocomial pathogen, associated with these serious and prevalent infections. |
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| Autores principais: | Gonçalves, Vanessa Acúrcio da Silva |
| Assunto: | Staphylococcus epidermidis Biofilm-released cells Human blood Plasma Gene expression Células libertadas do biofilme Sangue Expressão genética |
| Ano: | 2016 |
| 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 |
| Resumo: | Staphylococcus epidermidis colonizes healthy human skin and mucosa as a commensal microbe. It is an opportunistic pathogen, since it requires a major breach in the host innate defence. Also, this bacterial species has become one of the leading nosocomial pathogens, in particular medical devices-related infections such as intravascular catheters. Accordingly, S. epidermidis causes at least 22 % of bloodstream infections, detected in intensive care in the United Sates. The main factor that often sustains the commensal lifestyle of this bacteria is its remarkable capability to adhere to the surfaces of indwelling medical devices and subsequently form biofilms. Once a biofilm is completely developed, cells start to detach from the biofilm. The release of cells from biofilms plays a crucial role in spread of the infection, as they have been associated with acute infections such sepsis and devastating embolic events of endocarditis. However, despite its pathogenicity, the research regarding to the interaction between S. epidermidis biofilm-released cells (Brc) and human blood lies in an embryonic state. For a better understanding of the interaction between these cells and host immune system, Brc were characterized upon contact to human blood and plasma. Furthermore, virulence determinants were analyzed and its quantification performed by quantitative PCR. Our results revealed that S. epidermidis Brc display virulence potential. Interestingly, S. epidermidis Brc survival showed different responses between strains as well as donors. The transcriptome differences in response to immune cells between the strains studied enhance the particular characteristics inherent to each strain and, as a consequence, a particular behaviour developed when exposed to the host immune system. Thus, targeting the particular characteristics of Brc is important to prevent the severe acute infections associated with the release of cells from biofilms. In conclusion, the workflow described throughout this thesis provide an important contribution to the knowledge of the Brc, of this important nosocomial pathogen, associated with these serious and prevalent infections. |
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