A Dual Rheometer-Microscope Instrument for the Quantitative Characterization of Bacterial Biofilms

用于细菌生物膜定量表征的双流变仪-显微镜仪器

• 批准号: RTI-2019-00860
• 负责人: Virgilio, Nick
• 金额: $ 10.93万
• 依托单位: École Polytechnique de Montréal
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=667829
• 关键词: Dual; Rheometer; Microscope; Instrument; Quantitative

It is currently estimated that 80% of the planet's bacteria live in communities inside biofilms - a medium comprised of exopolysaccharides, DNA, proteins and various small molecules. A biofilm is a mechanically robust material that surrounds and protects the bacteria from the external world. As a result, these bacteria are generally more resistant or tolerant to antibiotics and disinfectants. The development of biofilms on medical devices, such as catheter and implants, and in living tissues, now poses some important issues, since intensive and prolonged treatments with antibiotics still often lead to treatment failure, and higher morbidity and mortality rates - this is a worldwide issue that still needs the development of efficient solutions. Biofilms also have useful properties, for example in the development of treatment processes for water and wastewater. Biofilm flocs allow the suspension of bacteria in the medium, or their adherence to inert supports onto which the biomass develops. As a result, understanding and controlling the properties of biofilms is of critical importance in these areas of research. Very recently, both interfacial and bulk rheology have been introduced as techniques to monitor quantitatively the viscoelastic properties of bacterial biofilms, which are directly related to the stability of the film. The commercial rheometer that we request in this proposal will be equipped with interfacial geometries, along with other various bulk measurement geometries, that will allow time-resolved, quantitative measurements of biofilms' viscoelastic properties, with a fluorescence microscope allowing microstructure and composition analyses. Previous work has demonstrated that this technique is particularly sensitive to biofilm composition, which can be controlled by gene knockout and by the external environment - temperature, composition of the media, etc. Since time-resolved measurements will be possible, quantifying the effects of perturbations, such as the addition of antibiotics, on the viscoelastic, microstructural and composition properties of biofilms will be possible. Finally, the installation of the rheometer in a Biosafety level 2 laboratory will allow the study of pathological strains such as Salmonella - a unique configuration in Canada. This original multidisciplinary program is a first collaboration between seven co-applicants and 4 collaborators with complementary expertises, including rheology, bacterial microbiology, interfacial science, water/wastewater treatment processes, veterinary medecine, and pediatrics, from Polytechnique Montreal, Université de Montréal, INRS Institut Armand-Frappier, and Stanford University.

目前估计地球上 80% 的细菌生活在生物膜内——生物膜是一种由胞外多糖、DNA、蛋白质和各种小分子组成的介质，生物膜是一种机械坚固的材料，包围并保护细菌免受外界影响。因此，这些细菌通常对抗生素和消毒剂具有更强的抗药性或耐受性。医疗器械（例如导管和植入物）以及活体组织中生物膜的形成现在带来了一些重要问题，因为生物膜的强度很高。抗生素的长期治疗仍然经常导致治疗失败以及更高的发病率和死亡率——这是一个仍然需要开发有效解决方案的世界性问题。生物膜也具有有用的特性，例如在水和水处理工艺的开发中。生物膜絮凝物允许细菌悬浮在介质中，或者它们粘附在生物质生长的惰性载体上，因此，了解和控制生物膜的特性在最近的这些研究领域中至关重要。界面和本体流变学已被引入作为定量监测细菌生物膜粘弹性特性的技术，这与膜的稳定性直接相关，我们在本提案中要求的商业流变仪将配备界面几何形状以及其他各种本体。测量几何形状，这将允许对生物膜的粘弹性特性进行时间分辨、定量测量，并使用荧光显微镜进行微观结构和成分分析，之前的工作表明该技术对生物膜成分特别敏感。可以通过基因敲除和外部环境（温度、介质成分等）进行控制。由于时间分辨测量将成为可能，因此可以量化扰动（例如添加抗生素）对粘弹性、微观结构和成分的影响最后，在生物安全二级实验室中安装流变仪将可以研究沙门氏菌等病理菌株——这是加拿大的独特配置。共同申请人和来自蒙特利尔理工学院、蒙特利尔大学、INRS 阿尔芒-弗拉皮尔研究所和斯坦福大学的七名具有互补专业知识的合作者之间的合作，包括流变学、细菌微生物学、界面科学、水/废水处理工艺、兽医学和儿科。