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Gewählte Master / Diploma Thesis:

Agnes Berger (2013): Antimicrobial activity testing of plant-derived compounds - specific focus on enterococci.
Master / Diploma Thesis - Institut für Lebensmittelwissenschaften, BOKU-Universität für Bodenkultur, pp 291. UB BOKU obvsg

Data Source: ZID Abstracts
Enterococci are Gram-positive cocci, forming a natural part of the microflora of the mammalian gastrointestinal tract. They are applied in cheese production and as probiotics. However, enterococci have become an alarming problem because of their emerging antibiotic resistance and the increasing numbers of nosocomial infections. Multidrug resistant and especially vancomycin resistant enterococci are considered as a risk group, as they are among the most therapeutically challenging infections and there are only few drugs left for a successful treatment. The emerging antibiotic resistance increases the importance of new antibacterial substances. One source for such agents are plants. En. faecalis and En. faecium strains were examined for their resistance against ten different antibiotics with phenotypic and genotypic methods. The phenotypic methods include the agar disk diffusion, the microdilution and the Etest. The genotypic methods include the detection of resistance genes with PCR and microarray. The results of all methods were reproducible and coincided well. Additionally, different plant extracts were tested for their inhibiting effects against enterococci, including extracts from Alpinia katsumadai, Salvia officinalis, Thymus spp. and Vitis vinifera. The ethanol extracts of Salvia officinalis and blue grapes, as well as the oil from Alpinia katsumadai showed inhibiting effects on the tested En. faecium strains. The applied testing technique was a modified version of the microdilution test. The dye resazurin in combination with the electron mediator menadione was chosen as the optimal detection reagent, after testing several dyes for their colouring properties for enterococci. One of the mechanisms causing antibiotic resistance are efflux pumps. These pumps extrude antibiotics out of cells even before they can be effective. In this master thesis a method developed for the detection of this resistance mechanism in E. coli was adapted for Enterococcus species.

Beurteilende(r): Kneifel Wolfgang
1.Mitwirkender: Domig Konrad

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