Leise Riber

Aktuel forskning

Interactions of bacterial communities and prevalence of antimicrobial resistance genes in natural environments. Molecular mechanisms involved in spread and acquisition of antibiotics resistance through horizontal gene transfer among bacterial populations. Dynamics of plasmid transfer and stability within bacterial species in complex environments. Transfer frequencies and host range of various conjugative plasmids are studied by a cultivation independent single cell based transfer-reporter gene approach using the Green Fluorescent Protein (GFP) together with Fluorescence-activated cell sorting (FACS).

Molecular microbiology; Construction and optimization of molecular methods for tagging plasmids and bacterial chromosomes for use in the transfer-reporter gene based system when studying horizontal gene transfer on a single cell level.

Plasmid biology; Studying and characterizing environmental conjugative plasmids with respect to finding gene determinants involved in plasmid dependent regulation of biofilm formation and plasmid transfer.

Aktuel forskning

Interactions of bacterial communities and prevalence of antimicrobial resistance genes in natural environments. Molecular mechanisms involved in spread and acquisition of antibiotics resistance through horizontal gene transfer among bacterial populations. Dynamics of plasmid transfer and stability within bacterial species in complex environments. Transfer frequencies and host range of various conjugative plasmids are studied by a cultivation independent single cell based transfer-reporter gene approach using the Green Fluorescent Protein (GFP) together with Fluorescence-activated cell sorting (FACS).

Molecular microbiology; Construction and optimization of molecular methods for tagging plasmids and bacterial chromosomes for use in the transfer-reporter gene based system when studying horizontal gene transfer on a single cell level.

Plasmid biology; Studying and characterizing environmental conjugative plasmids with respect to finding gene determinants involved in plasmid dependent regulation of biofilm formation and plasmid transfer.

CV

Research interests

My main focus is on finding new strategies to limit the occurrence of plasmid-borne spread of antimicrobial resistance. The spread of antimicrobial resistance among bacterial populations is mainly due to the acquisition of resistance genes located on transferable plasmids obtained through horizontal gene transfer. New ways of reducing the spread and selection of resistance therefore include the disturbance of the dynamics of plasmid transfer and stability. Current work areas include studying molecular mechanisms involved in horizontal gene transfer and plasmid stability, as well as baseline studies of the prevalence and dissemination of resistance plasmids in complex natural environments. Areas of expertise include various techniques within molecular microbiology and bacterial genetics. Main focus is on construction of bacterial reporter strains and cloning of conjugative plasmids using mini-mu and Tn7 based transposon systems for studies of horizontal gene transfer (HGT) and plasmid dynamics in complex environments. Additionally, HGT studies include expertise within cell counting using flow cytometry as well as cell sorting for 16S sequencing using Fluorescence activated cell sorting (FACS).

Education

2003-2007 Ph.D., (Molecular Microbiology). Roskilde University, Roskilde.

1996-2003  Cand. Polyt., (Chemistry, Biotechnology). Technical University of Denmark, Lyngby.

Employment

2010-        Post-doctoral Fellow, (Molecular Microbiology). University of Copenhagen, Institute of Biology, KU-BIO, Copenhagen.

2008-2010 Post-doctoral Fellow, (Molecular Microbiology and Food Microbiology). National Food Institute, Technical University of Denmark, DTU-FOOD, Mørkhøj.

2006-2007   Post-doctoral Fellow, (Molecular Microbiology). Roskilde University, Roskilde.

Publications and Presentations

5 publications in international peer reviewed journals; about 10 contributions to

conferences (posters, oral presentations), workshops, etc. Once receiver of the

Scholarship “Carlsbergs Mindelegat for Brygger J.C. Jacobsen”.

1.         Charbon, G., et al., Suppressors of DnaA(ATP) imposed overinitiation in Escherichia coli. Mol Microbiol. 2011. 79(4): p. 914-28.

2.         Gronlund, H., et al., Microarray-based genotyping of Salmonella: inter-laboratory evaluation of reproducibility and standardization potential. Int J Food Microbiol. 2011. 145: p. S79-85.

3.         Riber, L., et al., Loss of Hda activity stimulates replication initiation from I-box, but not R4 mutant origins in Escherichia coli. Mol Microbiol, 2009. 71(1): p. 107-22.

4.         Riber, L. and A. Lobner-Olesen, Coordinated replication and sequestration of oriC and dnaA are required for maintaining controlled once-per-cell-cycle initiation in Escherichia coli. J Bacteriol, 2005. 187(16): p. 5605-13.

5.         Riber, L., et al., Hda-mediated inactivation of the DnaA protein and dnaA gene autoregulation act in concert to ensure homeostatic maintenance of the Escherichia coli chromosome. Genes Dev, 2006. 20(15): p. 2121-34.