In immunodeficient patients, for example with cystic fibrosis (CF), the opportunistic pathogen Staphylococcus aureus causes chronic infections of respiratory tract that are treated with antibiotics (ATB) in the long term. However, exposure to antibiotics can lead to persistence, thereby result a recurrence of infection. The aim of this work was to examine in selected pairs of S. aureus chronological isolates from the respiratory tract of CF patients how their ability to form persisters is changing in time. I have found that the ability to persist within the clonal pair does not change significantly after two years of survival in the host, and that the ability to persist depends on the adaptative mutations of the isolates. Persister formation may depend on mutations in operon of the alternative sigma B factor (sigB) and the major virulence gene regulator (agr). By dual staining with DioC2(3) and To-pro-3, I was able to determine the changes in membrane potential and membrane permeability during the killing curve with ATBs. The distribution into subpopulations according to these parameters depends primarily on the antibiotic used. I conclude that various antibiotics can induce different mechanisms causing a persistent state. Futhermore, I have constructed plasmids with a labeled promoter to determine...
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:446669 |
| Date | January 2019 |
| Creators | Kotková, Hana |
| Contributors | Lichá, Irena, Tkadlec, Jan |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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