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Gewählte Master / Diploma Thesis:

Philipp Palmstorfer (2012): Molekulare Identifizierung von Listerienisolaten mittels 16S rRNA Sequenzanalyse und phylogenetische Ermittlung von Verwandtschaftsverhältnissen.
Master / Diploma Thesis - Institut für Lebensmittelwissenschaften, BOKU-Universität für Bodenkultur, pp 120. UB BOKU obvsg

Data Source: ZID Abstracts
Abstract:
The aim of this study was to identify 544 listeria isolates from various sources (foods, environmetal saples, patient isolates, etc.) by sequence analysis of the 16S rRNA sequence and to infer relationships between the isolates by exemplary phylogenetic trees. In detail, the 16S rRNA section was sequenced and a database search was performed at the NCBI database to identify the isolates. Cluster analysis of all representative listeria species and phylogenetic trees based on 16S rRNA segments were created. For the creation of phylogenetic trees, the maximum parsimony and maximum likelihood methods were applied for comparison purposes. To check the reproducibilty of the methods, 8 listeria reference sequences and 14 additional listeria reference genome sequences were included in this study. Cluster analysis and calculation of the phylogenetic trees were carried out in order to compare their relationship to listeria isolates applied in this study. The cluster analysis revealed comparable results among reference strains and isolates with the use of a pairwise alignment. Species specific comparison achieved a high strain-similarity. The phylogenetic trees showed similar patterns to the cluster analysis and also showed the known familiar relationships independently of the NCBI-imported reference sequences. The selected section (16S rRNA) was valuable for the identification of listeria isolates and further the creation of phylogenetic trees. Careful attention has to be paid to achieve a uniform length of the obtained sequence sections in order to prevent misleading similarity values among sequences. Both trees (computed with Maximum Likelihood and Maximum Parsimony) showed the same topology, suggesting the proper arrangement of the species in the trees by the applied methods.

Beurteilende(r): Kneifel Wolfgang
1.Mitwirkender: Domig Konrad
2.Mitwirkender: Zunabovic-Pichler Marija

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