Elucidating stress responses in bacterial biofilms using electromagnetic sensors and transcriptome analysis on single-cell level

点击翻译按钮获取中文摘要

Biofouling is ubiquitous in nature. The formation of these so-called biofilms poses significant challenges for technical systems in aqueous environments. Biofilms are sessile formations of bacteria on substrates which coexist symbiotically mutually profiting metabolically and sharing protection strategies. Bacteria organized in biofilms are significantly better protected against environmental hazards compared to the planktonic state in free solution. Besides being a major economic problem due to the reduction performance of technical systems (membranes, material properties, etc.) biofilms have become a major thread for human health. Their short genetic cycle allows for fast evolutionary adaptability which results, e.g., in the development of resistance to most antibiotics. This is a common problem in hospitals where these persistent biofilms are a source of severe infections and similar diseases.In order to developed more sophisticated anti-biofilm treatment strategies quantitative tools are required which elucidate the physiological and genetic adaptability of bacteria in biofilms when probed with anti-biofilm reagents, e.g., for cleaning or disinfection. The aim of this project is to provide such a tool which allows determining physiological (morphological) and genetic changes quantitatively on a single-cell level. This tool will be used on single-species biofilms which will be subjected to various anti-biofilm treatment procedures (stress) in order to induce physiological and genetic responses. The biofilms will then be dissolved to raw cell solutions using suitable enzymatic cocktails that target the extra-cellular matrix. The cell solutions are then subjected to microfluidic flow-through filtration and mechanical trapping on a single-cell level. Once mechanically immobilized the cells are accessible for electrical characterization using a microwave electrochemical impedance spectroscopy based sensor system. The data acquired from the system will be matched to equivalent models extracting relevant parameters which are compared among bacteria originating from differently treated biofilms. In addition the cells will be extracted for single-cell gene expression analysis allowing correlation of electrical (physiological) changes to genetic changes.This combined approach will allow correlating stress responses of bacteria organized in biofilms with changes in their physiology and gene expression and thus allow the quantitative determination of responses of biofilms to various anti-biofilm treatment strategies. Using this tool a more detailed understanding of the mechanisms underlying the adaptability of bacteria in biofilms to treatment strategies will be enabled which will be the foundation for development of efficient strategies for biofilms removal.