Dr. Sofiane El-Kirat-Chatel presents Antimicrobial agents, where do they bind, how do they act? Analysis at the nanoscale

Antimicrobial agents, where do they bind, how do they act? Analysis at the nanoscale
Sofiane El-Kirat-Chatel
CNRS – University of Bordeaux
Institute of Chemistry & Biology of Membranes & Nano-objects (CBMN)
Bordeaux, France

In the last two decades, atomic force microscopy (AFM) has emerged as an attractive tool to determine the physico-chemical properties of biological samples. The possibility to operate in physiological conditions is a major advantage of this technique as it allows, e.g, to follow changes upon exposure to external stresses. During this presentation, I will briefly present the different AFM modalities we are using (imaging, single-molecule force spectroscopy and single-cell force spectroscopy) to study the impact of antimicrobial agents. I will illustrate the advantage of our approaches through examples on: i) the effect of caspofungin, an antifungal lipopeptide, on yeast cells; ii) the action of squalamine, a steroid-polyamine with a spermidine motif, on the pathogenic bacteria Staphylococcus epidermidis; and iii) the specific recognition of Staphylococcus aureus by phages. The combination of multi-scale tools offers the possibility to determine the impact of external stresses from the molecules to the microbial suspension and to explain phenotypes observed upon cell treatments.