Research Group "Biofilms"

Biofilms are the preferred sessile life form of microorganisms. They have a complex three-dimensional structure in which the microbes are embedded in a highly variable polymeric matrix consisting of proteins, carbohydrates, nucleic acids and other polymers. Biofilms can be formed on almost all artificial and natural surfaces. They play an ecologically important role in the environment, but are disturbing and harmful in urban infrastructure (e.g., water pipelines) or in industrial processes (food industry). If biofilms occur in the human body, e.g. on catheters, implants, wound infections, they often lead to diseases that are difficult to treat and often chronic. Mature biofilms can hardly be completely eliminated by drug treatments because the microbes embedded in a biofilm benefit from the protective matrix environment and thus have a greatly reduced sensitivity to disinfectants, antibiotics and even the immune system. Therefore, the research group is dedicated to different approaches to biofilm control.

Current Projects

Establishment of in vitro biofilm models for time-resolved standardized analysis of active substances

Project duration: 01.04.2021- 31.03.2026

The overall objective of the joint project Smart M2IP (basic technology 1) within the Leibniz Center for Photonics in Infection Research (LPI) is the research and implementation of innovative imaging platforms for the qualitative and quantitative 2D, 3D and 4D analysis of biological systems as well as interactions with external influencing factors or active agents. The UKJ is responsible for the subproject ''Provision of reference analytics and clinical material as well as biological in vitro and in vivo models' the IIMK takes over the task to establish different biofilm platforms to enable pharmacokinetic analyses of novel drugs in bacterial biofilms. Various PhD projects will be attached to the subproject, which will work on specific scientific questions and establish and standardize the biofilm models and make them available to the LPI.

The project is funded by the German Federal Ministry of Education and Research under grant number 13N15467.

Biologicals to fight aginst bacterial biofilms

Project period: 01.07.2021- 30.06.2026

Since bacterial biofilms have up to 100-fold higher tolerance to antimicrobial agents, biofilm-associated infections are difficult to treat effectively. Therefore, in this project the effect of bacteriophages and probiotically active microorganisms on bacterial biofilms of the most common biofilm-forming human pathogenic species, P. aeruginosa, K. pneumoniae, S. aureus will be investigated. At the same time, novel optical analysis methods for detection of efficacy in biofilms will be established for LPI.

The PhD project is carried out within the framework of the Leibniz Center for Photonics in Infection Research (LPI) and is funded by the German Federal Ministry of Education and Research under the grant numbers 13N15720 and 13N15467.

Galleria mellonella model for the investigation of therapeutics and implant materials against bacterial infections and colonization

Project period: 01.04.2021- 31.03.2024

Infections due to biofilm formation on implants are becoming an increasing problem in industrialized countries due to demographic changes and increasing numbers of implantations. Antimicrobial treatment is difficult and usually the implant has to be removed completely. Therefore, much research is being done on improved antimicrobial surfaces and therapeutic options. However, in vitro experiments do not reflect the actual properties of biofilms because they are strongly influenced by host factors. The Galleria mellonella larval model provides a simplified and manageable system to study biofilm formation and treatment in a more natural environment. Furthermore, the host response can be considered at the same time.

Development and validation of a clinical MBEC assay for individualization of biofilm-associated infections

Project duration: 01.09.2020- 31.08.2024

Cooperation partners: Leiden University, Uppsala University, University of Wine, University of Bolognia, Paul-Ehrlich-Institut (PEI)

Pseudomonas aeruginosa and Burkholderia cenocepacia are two of the most critical pathogens in cystic fibrosis (CF), forming difficult-to-treat biofilms in the lungs and associated with high mortality. Targeted therapeutic strategies that allow eradication of the formed biofilms are essential for successful therapy. However, the activity of antibiotics in biofilms is not reflected by the routinely determined minimal inhibitory concentration (MIC). The determination of the minimum biofilm-adherent concentration (MBEC), which is usually much higher than the MIC and often therapeutically inaccessible, is currently not performed as a routine diagnostic test; mainly because of methodological hurdles. Therefore, the focus of this project is on the establishment of routine methods and standardization, as well as a systematic analysis of CF isolates and correlation between MBEC of the respective isolate and patient outcome. The aim is to determine whether personalized biofilm diagnostics can improve therapy in CF patients.

The project is being conducted within the Innovative Training Network (ITN) entitled Training towards Innovative Personalized Antibiotic Therapy (TIPAT) under grant numbers EUUZI72085 and funded by the European Union's Horizon 2020 research and innovation program under Marie Skłodowska-Curie grant agreement No. 861323.

Host response biomarkers for bacterial infections using RNA profiling and Raman spectroscopy

Project duration: 01.09.2020- 31.08.2024

Cooperation partners: Leiden University, Uppsala University, Wein University, University of Bolognia, Paul Ehrlich Institute (PEI)

Pathogenic bacteria, such as Staphylococcus aureus, can escape the immune response by invading host cells or by biofilm formation, leading to chronic recurrent infections. There is also evidence that, in addition to these escape strategies, bacteria specifically stimulate the immune system and suppress the immune response. Thus, it could be shown that Treg cells, which are differentiated by stimulation with the S. aureus toxin SpA-, act as anti-inflammatory counterparts of Th17. From other unknown S. aureus effectors lead to such immunosuppression and thus may play a critical role in establishing S. aureus persistence in chronic infections. This question, and the role of antimicrobial therapy in biofilm-associated infections, will be addressed in the project. The goal is to identify host markers that allow early indication of therapy success or failure, or chronicity.