Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

You searched for id:"handle:10900/84178". One record found.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


Universität Tübingen

1. Nguyen, Thien Ngoc Tran. Establishment and evaluation of Staphylococcus aureus strains with integrative reporter-plasmids for detection of cap and agr promoter activity and establishment of a 3D collagen model .

Degree: 2018, Universität Tübingen

Staphylococcus aureus (S. aureus) is a gram-positive bacterium with a “split personality”. Staphylococci are part of the normal skin flora, but can also cause skin and wound infections as well as fatal septicaemia. The mechanism of transition from apathogenic colonisation to invasive infections is modulated by several gene regulators. An important gene regulator is the Accessory Gene Regulator (Agr) system, which is responsible for the modulation of hundreds of genes. The agr locus consists of two transcriptional units expressed from two divergent promoters P2 and P3. The Agr system is a typical two-component system and is regulated by a quorum sensing mechanism, whereby staphylococci produce an extracellular autoinducing peptide (AIP). AIP binds to its receptor, the histidine kinase AgrA and causes the autoinduction of the Agr operon itself through the agr P2 promoter, as well as the activation of various target genes through the agr P3 promoter. Gene expression is activated by a regulatory RNAIII molecule (originating from the agr P3 promoter) and, among other regulatory functions, leads to the expression of the capA-P biosynthesis cluster, which leads to the synthesis of capsular polysaccharide (CP). The capA-P operon is controlled by the capP promoter upstream of capA. CPs protect staphylococci from opsono-phagocytosis, but also mask surface molecules and therefore reduce the ability of staphylococci to adhere to tissue surfaces. Analysis using fluorescence-activated cell sorting and immunofluorescence staining have revealed that not all staphylococci within a single culture produce CP in the post-exponential phase, but rather present phenotypically heterogeneous. The aim of this study was to establish reporter strains to simultaneously analyse the activity of both the agr-P3 and the cap-P promoter on a single cell level. For this, promoters with fluorescence proteins were cloned into integration vectors and integrated into the S. aureus chromosome. We used integration vectors that either used the S. aureus pathogenicity island I (SaPI-I) as an attachment site, or integrated with a phage (attachment site geh). Plasmids with various combinations of fluorescence genes Venus (ven) or Cerulean (cer) and different selection markers were tested. The generated strains were verified using PCR to confirm correct integration, and phenotypically analysed using confocal fluorescence microscopy. We were able to show that all reporter strains had successfully integrated the vector plasmid at the correct attachment site. In one case, partial deletion of the integration plasmid was observed. In another case, we were able to detect multiple integration of the vector. Fluorescence microscopy revealed that 1. Agr-activity is largely homogeneous and is highest in the post-exponential phase. 2. cap-A activity is also at highest levels in the post-exponential phase. 3. cap-P activity is highly heterogeneous within a single culture. 4. Promoter fusion constructs with Venus displayed a stronger fluorescence signal than fusion… Advisors/Committee Members: Wolz, Christiane (Prof. Dr.) (advisor).

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Nguyen, T. N. T. (2018). Establishment and evaluation of Staphylococcus aureus strains with integrative reporter-plasmids for detection of cap and agr promoter activity and establishment of a 3D collagen model . (Thesis). Universität Tübingen. Retrieved from http://hdl.handle.net/10900/84178

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Nguyen, Thien Ngoc Tran. “Establishment and evaluation of Staphylococcus aureus strains with integrative reporter-plasmids for detection of cap and agr promoter activity and establishment of a 3D collagen model .” 2018. Thesis, Universität Tübingen. Accessed November 20, 2018. http://hdl.handle.net/10900/84178.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Nguyen, Thien Ngoc Tran. “Establishment and evaluation of Staphylococcus aureus strains with integrative reporter-plasmids for detection of cap and agr promoter activity and establishment of a 3D collagen model .” 2018. Web. 20 Nov 2018.

Vancouver:

Nguyen TNT. Establishment and evaluation of Staphylococcus aureus strains with integrative reporter-plasmids for detection of cap and agr promoter activity and establishment of a 3D collagen model . [Internet] [Thesis]. Universität Tübingen; 2018. [cited 2018 Nov 20]. Available from: http://hdl.handle.net/10900/84178.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Nguyen TNT. Establishment and evaluation of Staphylococcus aureus strains with integrative reporter-plasmids for detection of cap and agr promoter activity and establishment of a 3D collagen model . [Thesis]. Universität Tübingen; 2018. Available from: http://hdl.handle.net/10900/84178

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.