The Bacteria&Materials Interaction Group focuses on understanding, predicting and controlling material-bacteria interactions for health-related applications. In particular, we combine interdisciplinary knowledge in the pursuit of understanding how bacteria adhere to surfaces, and how the adhesion can be controlled. Among our core strengths are the expertise ranging from microbiology to biomaterials, and the long-term experience in working with hospitals, academic partner institutions, and industry.

Our key research aspects include:

• Studying mechanisms of bacterial adhesion on surfaces, particularly bacterial mechanobiology, aiming at antibacterial and anti-adhesive surfaces
• Studying mechanisms of biofilm resistance toward antimicrobials
• Development of biosensors for detection of antimicrobial resistant bacteria
• Design of novel approaches for treatment of antimicrobial resistance

Bacteria-surface interactions

Upon sensing and interacting with surfaces, bacteria trigger a variety of changes in gene expression, including the genes essential for cell-cell communication, motility and surface attachment. Although changes in these phenotypes have been observed, the mechanisms used by bacterial cells for sensing and responding to surfaces are not well understood. To develop novel classes of materials that inhibit or reduce bacterial adhesion or proliferation, a better understanding of these mechanisms is necessary. Our group is interested in studying the underlining mechanisms of surface sensing at the molecular level and the consequent impact on cell adhesion.

We have close collaborations with Dr. Dominik Abt (Cantonal Hospital St. Gallen), (Dr. Kurt Ruffieux (protecturo), Prof. Leo Eberl (University of Zurich), Prof. Henny van der Mei (University Medical Center Groningen) and Prof. Songmei Wu (Beijing Jiaotong University). We greatly acknowledge support from Innosuisse.

The majority of infections are caused by bacterial biofilms. Bacteria living in biofilms can tolerate much higher antibiotic concentrations compared to planktonic bacteria and survive long enough to evolve antimicrobial resistance (AMR). Our group aims to investigate how bacteria generate resistant during biofilm formation on medical devices. This enables to gain more insight into the underlying mechanisms can then be leveraged to develop novel antimicrobial strategies to prevent biofilm-associated infection and AMR.

We have close collaboration with Prof. Jeremy Webb (University of Southampton), Prof. Henny van der Mei (University Medical Center Groningen), Dr. Frank Schreiber (BAM) and Dr. Christian Ahrens (Agroscope). We greatly acknowledge the support from the Swiss National Science Foundation.

Understanding mechanism of biofilm resistance toward antimicrobial surfaces by identifying involved genes and pathways.

We combine material science, chemistry, and biology to design non-invasive biosensors highly specific for resistant bacteria. The biosensors, including those for evaluation of pneumonia etiology, dental diseases and sepsis, have potential to allow surgeons to achieve rapid diagnosis and initiate appropriate treatment timely.

Diverse projects are carried out in close collaboration with Dr. Werner Albrich and Dr. Christian Kahlert (Cantonal Hospital St. Gallen), Dr. Saso Jezernik and Dr Christian Jäggi (Bioinitials), Dr. Silvia Generelli (CSEM), Dr. Stefan Stübinger (University of Basel). We greatly acknowledge support from Innosuisse.

To reduce development of antimicrobial resistance, we utilize natural materials, hazard-free and easily accessible approaches to replace antibiotics to treat biofilm associated chronic wounds. These bioinspired wound dressings not only allow elimination of biofilms but also promote tissue re-epithelization and wound healing.

This project is carried out in close collaboration with Dr. Zhihao Li (Triemli Hospital), Dr. Dominik Abt (Cantonal Hospital St. Gallen), Professor Sven Panke and Dr. Martin Held (ETHZ).

Our group hosts a Biosafety Class II Lab where we work group works with different bacterial strains including Gram-negative and Gram-positive species and multi-resistant pathogens. We study biofilms in microtiter plates, flow chambers, as well as microfluidic systems under static or dynamic conditions. Bacterial adhesion and biofilms on surfaces are analyzed by different methods such as Crystal violet assays, Fluorescence assays, Microscopy (Wide-field, CLSM, SEM), Real-time quantitative PCR.

Hervé Straub

PhD Student

herve.straub@empa.ch

Keywords: microfluidics, optical microscopy, in vitro biofilm assays, bacteria and material interactions

Jules Valentin

PhD Student

jules.valentin@empa.ch

Keywords: Microbiology, molecular biology, interface bacteria/material

Fei Pan

PhD Student

fei.pan@empa.ch

Keywords: Biointerface construction, Biomaterial & Biosensor design, Biomaterial & Biointerface characterization

Marc Tala

Project Employee

marc.tala@empa.ch

Keywords: bacterial culture, microbiology, in vitro biofilm assays, probiotics

Flavia Zuber

Laboratory technician

flavia.zuber@empa.ch

Microbiology, in-vitro biofilm assays, cell culture, cytotoxicity testing

Stefanie Altenried

Laboratory technician

stefanie.altenried@empa.ch

In vitro biofilm formation and assessment, Microbiology, Biotechnology, molecule biology

Dr. Zhihao Li

Guest scientist

zhihaoli@empa.ch