For general public

Microbiology at the nanoscale

For years, microbiologists have been using microscopy to look at microbes. The invention of the light microscope in the 17th century enabled them to observe the morphological details of individual cells directly. Later, fluorescence microscopy techniques were developed to localize specific molecules in cells and to visualize the organization and heterogeneity of cells in microbial communities. Yet, the spatial resolution of optical microscopy is limited by the diffraction limit of light, meaning the arrangement and interactions of the individual molecules cannot be resolved.

Recent advances in nanotechnology have offered new opportunities to study single cells and single molecules in microbiology. Since 1997, the Dufrêne group uses atomic force microscopy to study microbes at molecular resolution, with the goal to address fundamental questions in a way that was not previously possible.

Recent breakthroughs include: deciphering the supramolecular architecture of microbial cells, understanding the molecular elasticity of cell surface molecules and its role in adhesion and mechanosensing, and elucidating the spatial distribution of cell surface receptors and their stress-induced clustering. These studies have provided key insights into the structure and functions of cell surfaces, and have contributed to the growth of the emerging field of live-cell nanoscopy, which should have an important impact on biology and medicine. Achieving these goals is possible owing to successful collaborations with experts in molecular microbiology.

Currently, our ambition is to push the limits of nanoscopy beyond state-of-the-art to establish it as an innovative platform for studying microbial adhesion and biofilm formation. Biofilms are currently estimated to be involved in more than 65 % of hospital-acquired (nosocomial) infections. These surface-associated microbial communities lead to infections that are difficult to fight because many cells in the biofilm are protected from host defenses and are resistant to many antibiotics. We whish to understand how pathogens use their surface molecules to guide cell adhesion and trigger infections, and to develop anti-adhesion strategies for treating biofilm-infections.