Know4Nano

Presenters

Dr. Jasmina Vidić

Research engineer
INRAE, Micalis Institute, Université Paris-Saclay, France

Dr. Vidić received a PhD in physical chemistry at the University of Belgrade in 1999 and an HDR in biophysics at the University Paris 7 in 2010. She authored and co-authored 150 peer-reviewed papers and 3 patents. Dr Vidic was the project leader in several French national projects (ANR, DIM, Poc in Labs, EUGLOH), one international project BioAsia, several bilateral projects Campus France with Serbia, Portugal, Czech, and Italy. She is a WPL of two EU projects. Dr Vidic is dedicated to the development of new types of biosensors for the analysis of bacteria, membranes, proteins, and DNA. Her experience includes designing SPR immunosensors for pathogens such as the influenza virus, prion proteins, and odor molecules. She also created electrochemical biosensors using DNA probes, aptamers, and antibodies to detect and monitor pathogens such as hepatitis A virus, influenza virus, B. cereus, Campylobacter, E. coli, and S. aureus. Currently, her research focuses on detecting bacterial pathogens and their antibiotic resistant gens directly in foods, such as milk and meat, as well as in water. Additionally, Dr Vidic is involved in projects in nanobiotechnology, including the development of bimetallic oxide nanoparticles with antibacterial and antioxidant properties for smart food packaging. She is also working on nanostructured surfaces aimed at amplifying optical signals, such as chemiluminescence and fluorescence.

Talk Title: Bacterial detection in real samples: case of Staphylococcus aureus adaptation to serum and milk

Staphylococcus aureus is one of predominant cause of infections in mammals that is challenging to treat, a consequence of its ability to develop antibiotic resistance and adapt to host defenses. Here, we report that S. aureus adaptation to natural environments such as serum and milk, triggers reversible phenotypes with a high degree of tolerance to radical oxygen species and antibiotics. Moreover, compared to S. aureus cells grown in a lab medium, S. aureus adapted to serum and milk was more virulent in vivo. By combining analytical biochemistry and electron microscopy we found that S. aureus integrated exogenous fatty acids in their plasma membrane leading to cell structural modifications. While serum-adapted S. aureus cells became retracted, lost pigment and showed decrease envelop thickness and increase membrane fluidity, the milk-adapted cells were of high diameter and envelop thickness, have rigid membrane, low permeability and increased carotenoid production. Our work demonstrates that natural environments trigger adaptive phenotypes that may prevent bacterial tracking using biosensors based on antibodies and aptamers selected to bind S. aureus cells growth in lab conditions.

This project is funded by the European Union under Horizon Europe GA 101159710