SANBACT

The proposed program falls within the field of health safety and materials hygiene. It’s focused on the prevention and the battle against the pathogenic bacterial adhesion and the hazardous biofilms formation using methods which enable the eco-preservation of the environment. The program particularly features on the surface modification of industrial materials (plastics, metals) used in very diverse domains (medical, pharmaceutical, food, etc.) in the aim of providing them one or several antibacterial functionalities: anti-bioadhesive (based on physical and physico-chemical effects) combined or not combined with bactericidal properties, bacteriostatical properties or a "slow down growth” effect. All these properties and combined effects can be summarized as antibiofilm effects (biological effect). Thus, these new surfaces should be able to reduce the consumption of biocides and water now needed to ensure a hygienic status to the contaminated materials during the cleaning/disinfection procedures generating a significant amount of effluent. Consequently, this project exhibits a threefold interest: economical, environmental and of public health. New surfaces will be developed through an integrative and multiscale approach of the bioadhesive phenomena . In this new approach, the size, the morphology, the presence or absence of exocellular structures as well as the physicochemical and physiological caracterictics of the targeted bacteria will be necessarily taken into account. These surfaces are obtained either by grafting or by deposition of bioactive substances (i.e. "natural" substances acting on the "development cycle" of the bacteria) or molecules with defined specificities (hydrophobic to hydrophilic) and that, in order to be able to answer to a variety of applicative situations. In all cases, only raw materials compliant with the environmental legislation (REACH, Biocides) will be implemented. Their realization will lead to original structures and to specific physico-chemical properties tightly controlled via multi scale analysis (nanometric to macroscopic). These new anti-bacterial surfaces will have to be validated for conventional materials used in different technological fields of application. Due to their specificities, sampling and analysis methodologies adapted to the measurement of low levels of biocontamination will necessarily have to be developed. That’s why, in parallel with the "surface engineering" part of the project, methods for the sampling and the recovery of contaminating flora and techniques for biocontamination evaluation with detection limits below 10 cells / mm ² will be developed and / or improved. Through a multidisciplinary and multi-scale approach the project will lead to significant advances in the scientific knowledge of: - Bacteria / new surfaces interactions and especially the role of each component of the cell envelope (pili, flagella, capsules ...) in these interactions. - Reactivity of bacterial cells after contact with these native or modified abiotic surfaces (physiological changes which can result in morphological modification and growth modification or in a variation in their genetic expression and in their virulence expression...). This set of knowledge is now essential in a process of rational and effective control of surface biocontamination. Result of a federative multidisciplinary approach linking complementary skills, the project combines actors from institutional research laboratories (INRA, AgroParisTech, CNRS, Universities), from technical centers (CTTM and ISHA) and from industial (Eudica) who already worked together.