DecLiq

Biofilm removal from medical or industrial equipment is a major hygiene concern to prevent dissemination of pathogenic microorganisms from contaminated surfaces. As an alternative to conventional chemical decontamination that relies on environmentally hazardous reagents, cleaning procedures of confined surfaces based on capillary detachment of surface-attached bacteria by a moving air/liquid interface are attracting interest as greener methods. The cleaning efficiency of such methods depends on a complex interplay between physical, physico-chemical and microbiological parameters, and a clear picture of how these factors orchestrate is yet to be established. Moreover, the fate of bacteria that resist capillary cleaning and subsequent drying and how they may re-colonize surfaces has been unexplored. In this project, we propose to design an experimental platform and methodology allowing for high-throughput screening of the effect of such parameters on bacteria adhesion and fate. The setup and analysis chain will rely on (i) the design of a multiplexed microfluidic chip allowing to expose adhered bacteria to controlled fluid compositions, moving gas/liquid interfaces and drying times, (ii) a custom-made miniature flow control device for seamless integration of the whole fluidic setup on microscopy equipment, (iii) multimodal optical monitoring of the state and spatial organization of bacteria (reflection interference contrast, confocal and super-resolution microscopies), (iv) the design of molecular probes for smFISH (single molecule fluorescence in situ hybridization) transcriptomic analysis to monitor adhesion-related gene expression of bacteria. The design of this integrated device will be guided throughout the project by modelling and experimental feedback, to create an optimized platform offering unprecedented insights into the mechanisms controlling the efficiency of “capillary decontamination”.