Revealing the 3D architecture of mature colony biofilms with optical mesoscopy
Lead Research Organisation:
University of Strathclyde
Department Name: Physics
Abstract
The overall aim of this project is to understand the structure and function of mature biofilms, including spontaneously-assembling channels which we have discovered in bacterial colonies. Key to this approach is our use of the Mesolens, a unique UK optical invention with sub-cellular resolution and high temporal resolution which we have developed at Strathclyde.
Biofilms are one of the most pervasive and successful modes of life. They are aggregate communities of microorganisms attached to surfaces and are composed of cells, their extracellular matrices, extracellular polysaccharides and nucleic acids. All multi-cellular organisms are colonised by microorganisms that form biofilms, and they may be associated with persistent infections in plants, animals and humans, as well as the contamination of medical devices and implants. Biofilms are also considered a significant environmental hazard, responsible for biofouling and the reduction in quality of drinking water and may pose a significant threat to public health. The composition and structure of biofilms inherently offer protection to their constituent cells from environmental, mechanical and chemical factors contributing to their resilience.
Bacterial biofilms display remarkable changes as they grow and develop, and much of our understanding of biofilm architecture arises from imaging studies using scanning and transmission electron microscopy, atomic force microscopy, widefield epi-fluorescence microscopy, confocal laser scanning microscopy, super-resolution optical microscopy, lattice lightsheet imaging, correlative light-electron microscopy, optical coherence tomography40 and magnetic resonance imaging.
However, with all of these imaging techniques there is a strict compromise between the size of the imaging volume and the spatial resolution, limiting the study of biofilm architecture to either high-resolution microscopic imaging of early-stage colonies comprising very few cells, or low-resolution macro-scale imaging of late-stage colonies where individual bacteria cannot be resolved. Moreover, many of these techniques are limited to studying fixed material, and dynamic cell events are missed, or only the surface is visible and internal 3D detail cannot be observed. This limits our understanding of the dynamic architecture of biofilms. Our early results from using the Mesolens to study biofilm architecture have revealed intracolony channels for the first time, but we do not know the function of these channels: it may be possible to use these channels as drug delivery routes to aid more rapid biofilm dispersal.
We will use optical mesoscopy to study the architecture of mature biofilms comprising wild-type, mutant and mixed populations in 3D with sub-cellular resolution throughout so that we might learn about the structure and function of these newly discovered channels. Once a more thorough understanding has been reached, we aim to explore whether these channels can be used to shuttle antimicrobial agents into the biomass to facilitate disruption and dispersal of the biofilm.
Biofilms are one of the most pervasive and successful modes of life. They are aggregate communities of microorganisms attached to surfaces and are composed of cells, their extracellular matrices, extracellular polysaccharides and nucleic acids. All multi-cellular organisms are colonised by microorganisms that form biofilms, and they may be associated with persistent infections in plants, animals and humans, as well as the contamination of medical devices and implants. Biofilms are also considered a significant environmental hazard, responsible for biofouling and the reduction in quality of drinking water and may pose a significant threat to public health. The composition and structure of biofilms inherently offer protection to their constituent cells from environmental, mechanical and chemical factors contributing to their resilience.
Bacterial biofilms display remarkable changes as they grow and develop, and much of our understanding of biofilm architecture arises from imaging studies using scanning and transmission electron microscopy, atomic force microscopy, widefield epi-fluorescence microscopy, confocal laser scanning microscopy, super-resolution optical microscopy, lattice lightsheet imaging, correlative light-electron microscopy, optical coherence tomography40 and magnetic resonance imaging.
However, with all of these imaging techniques there is a strict compromise between the size of the imaging volume and the spatial resolution, limiting the study of biofilm architecture to either high-resolution microscopic imaging of early-stage colonies comprising very few cells, or low-resolution macro-scale imaging of late-stage colonies where individual bacteria cannot be resolved. Moreover, many of these techniques are limited to studying fixed material, and dynamic cell events are missed, or only the surface is visible and internal 3D detail cannot be observed. This limits our understanding of the dynamic architecture of biofilms. Our early results from using the Mesolens to study biofilm architecture have revealed intracolony channels for the first time, but we do not know the function of these channels: it may be possible to use these channels as drug delivery routes to aid more rapid biofilm dispersal.
We will use optical mesoscopy to study the architecture of mature biofilms comprising wild-type, mutant and mixed populations in 3D with sub-cellular resolution throughout so that we might learn about the structure and function of these newly discovered channels. Once a more thorough understanding has been reached, we aim to explore whether these channels can be used to shuttle antimicrobial agents into the biomass to facilitate disruption and dispersal of the biofilm.