Type IV Secretion in Gram-positive Pathogens

Type IV secretion systems (T4SS) are multiprotein complexes dedicated to the intercellular transport of proteins or protein-DNA complexes. T4SS translocate DNA and protein substrates across the cell envelope generally by a mechanism requiring direct contact with a recipient cell. Conjugative plasmid transfer is performed by a T4SS that transports DNA substrates to recipient cells in a contact-dependent process. My research group works on different research lines with the goal to understand and reduce the dissemination of antibiotic resistance via conjugative T4SS.

Enterococcus faecalis Type IV Secretion System

Molecular Monitoring of Microbial Contaminations

Detection and monitoring of pathogens, antibiotic resistance and transfer genes in the environment by molecular tools, such as PCR, quantitative real-time PCR and quantification of resistance transfer via fluorescence monitoring tools. Environmental samples of interest are contaminated surface waters and soils. Samples are derived from the largest sewage field in the world, the Mezquital Valley, Mexico and from anthropogenic German and Indian soils.

Channel transporting untreated wastewater from Mexico City

Antimicrobial Coatings / Biofilm Inhibitors

Molecular studies on bacterial pathogens derived from closed environments, such as the International Space Station (ISS). The Gram-positive isolates (focus on Staphylococcus and Enterococcus) are studied with respect to biofilm formation, presence of resistance genes and conjugative transfer capabilities. 

Novel silver and ruthenium-based antimicrobial surface coatings are tested for their mechanism of action and for applicability under microgravity conditions, on diverse medical devices and in water filter systems etc. The molecular reaction - metal stress - of the microorganisms upon contact with the coating is studied via RNA sequencing and quantitative real-time PCR.



Disruption of E. faecalis biofilm by AGXX
E. faecalis biofilm on silver mesh