Vancomycin Resistant Enterococcus faecium

Mariam Labrouzi, Marion Kracmerov√°, Brigita Meskauskaite, Anna Billeschou Larsen & Maria Christensen

Student thesis: Bachelor project


In the last decade, the microbial resistance towards antibiotics has grown remarkably and is becoming a prevalent issue. Within the area of research, the problem is explored in new ways. A method that can be applied in order to try to characterize bacterial antibiotic resistance is the sequencing of specific relevant genes. In this project, the issue at hand is the resistance of Enterococcus faecium to the last resort antibiotic vancomycin. In the capital region of Denmark, hospitals have seen outbreaks of infections caused by Vancomycin resistant Enterococci (VRE) bacteria, which has led to a regular screening of blood and stool samples from patients. Such samples were used for the purpose of this research paper. The aim was to establish whether transposons, with their corresponding vancomycin resistance genes and IS elements were identifiable in the Enterococcus faecium plasmids. The methods used were the purification of plasmids using the ZR BAC miniprep kit and the sequencing of the plasmids using the Oxford Nanopore MinION with the application of the 1D rapid protocol.
From the five plasmid samples that were sequenced, three presented fragments that could constitute a plasmid based on the LT603681 reference plasmid selected based on hit occurrence in all the plasmids. These samples were V1511, V1932, V1542 and V1877 and presented with the vanA gene cluster conferring vancomycin resistance. This isolate was found to be vancomycin resistant when plated on VRE selective plates which correlated with the finding of the full vanA gene cluster. The V1511 and V1932 plasmids were both missing the vanZ gene and presented with a considerably shortened vanX gene. Both of these strains were noticed to be vancomycin variable on plates which could indicate that the vanX gene plays a certain role in vancomycin variability.

EducationsBasic - Bachelor Study Program in Natural Science, (Bachelor Programme) Bachelor
Publication date28 May 2017
Number of pages65