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Schlomann BH, Pai TW, Sandhu J, Imbert GF, Graham TGW, Garcia HG. Spatial microenvironments tune immune response dynamics in the Drosophila larval fat body. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.12.612587. [PMID: 39345471 PMCID: PMC11429692 DOI: 10.1101/2024.09.12.612587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
Immune responses in tissues display intricate patterns of gene expression that vary across space and time. While such patterns have been increasingly linked to disease outcomes, the mechanisms that generate them and the logic behind them remain poorly understood. As a tractable model of spatial immune responses, we investigated heterogeneous expression of antimicrobial peptides in the larval fly fat body, an organ functionally analogous to the liver. To capture the dynamics of immune response across the full tissue at single-cell resolution, we established live light sheet fluorescence microscopy of whole larvae. We discovered that expression of antimicrobial peptides occurs in a reproducible spatial pattern, with enhanced expression in the anterior and posterior lobes of the fat body. This pattern correlates with microbial localization via blood flow but is not caused by it: loss of heartbeat suppresses microbial transport but leaves the expression pattern unchanged. This result suggests that regions of the tissue most likely to encounter microbes via blood flow are primed to produce antimicrobials. Spatial transcriptomics revealed that these immune microenvironments are defined by genes spanning multiple biological processes, including lipid-binding proteins that regulate host cell death by the immune system. In sum, the larval fly fat body exhibits spatial compartmentalization of immune activity that resembles the strategic positioning of immune cells in mammals, such as in the liver, gut, and lymph nodes. This finding suggests that tissues may share a conserved spatial organization that optimizes immune responses for antimicrobial efficacy while preventing excessive self-damage.
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2
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Ortiz de Ora L, Wiles ET, Zünd M, Bañuelos MS, Haro-Ramirez N, Suder DS, Ujagar N, Angulo JA, Trinh C, Knitter C, Gonen S, Nicholas DA, Wiles TJ. Phollow: Visualizing Gut Bacteriophage Transmission within Microbial Communities and Living Animals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.12.598711. [PMID: 38915633 PMCID: PMC11195241 DOI: 10.1101/2024.06.12.598711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Bacterial viruses (known as "phages") shape the ecology and evolution of microbial communities, making them promising targets for microbiome engineering. However, knowledge of phage biology is constrained because it remains difficult to study phage transmission dynamics within multi-member communities and living animal hosts. We therefore created "Phollow": a live imaging-based approach for tracking phage replication and spread in situ with single-virion resolution. Combining Phollow with optically transparent zebrafish enabled us to directly visualize phage outbreaks within the vertebrate gut. We observed that virions can be rapidly taken up by intestinal tissues, including by enteroendocrine cells, and quickly disseminate to extraintestinal sites, including the liver and brain. Moreover, antibiotics trigger waves of interbacterial transmission leading to sudden shifts in spatial organization and composition of defined gut communities. Phollow ultimately empowers multiscale investigations connecting phage transmission to transkingdom interactions that have the potential to open new avenues for viral-based microbiome therapies.
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Affiliation(s)
- Lizett Ortiz de Ora
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
| | - Elizabeth T Wiles
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
| | - Mirjam Zünd
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
| | - Maria S Bañuelos
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
| | - Nancy Haro-Ramirez
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
| | - Diana S Suder
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
| | - Naveena Ujagar
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
| | - Julio Ayala Angulo
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
| | - Calvin Trinh
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
| | - Courtney Knitter
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
| | - Shane Gonen
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
| | - Dequina A Nicholas
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, California, USA
- Center for Epigenetics and Metabolism, School of Medicine, University of California, Irvine, California, USA
| | - Travis J Wiles
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California, USA
- Center for Virus Research, University of California, Irvine, California, USA
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3
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Williams A. Multiomics data integration, limitations, and prospects to reveal the metabolic activity of the coral holobiont. FEMS Microbiol Ecol 2024; 100:fiae058. [PMID: 38653719 PMCID: PMC11067971 DOI: 10.1093/femsec/fiae058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 03/25/2024] [Accepted: 04/22/2024] [Indexed: 04/25/2024] Open
Abstract
Since their radiation in the Middle Triassic period ∼240 million years ago, stony corals have survived past climate fluctuations and five mass extinctions. Their long-term survival underscores the inherent resilience of corals, particularly when considering the nutrient-poor marine environments in which they have thrived. However, coral bleaching has emerged as a global threat to coral survival, requiring rapid advancements in coral research to understand holobiont stress responses and allow for interventions before extensive bleaching occurs. This review encompasses the potential, as well as the limits, of multiomics data applications when applied to the coral holobiont. Synopses for how different omics tools have been applied to date and their current restrictions are discussed, in addition to ways these restrictions may be overcome, such as recruiting new technology to studies, utilizing novel bioinformatics approaches, and generally integrating omics data. Lastly, this review presents considerations for the design of holobiont multiomics studies to support lab-to-field advancements of coral stress marker monitoring systems. Although much of the bleaching mechanism has eluded investigation to date, multiomic studies have already produced key findings regarding the holobiont's stress response, and have the potential to advance the field further.
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Affiliation(s)
- Amanda Williams
- Microbial Biology Graduate Program, Rutgers University, 76 Lipman Drive, New Brunswick, NJ 08901, United States
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Drive, New Brunswick, NJ 08901, United States
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Ji B, Zhao Y. Interactions between biofilms and PFASs in aquatic ecosystems: Literature exploration. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167469. [PMID: 37778566 DOI: 10.1016/j.scitotenv.2023.167469] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/26/2023] [Accepted: 09/28/2023] [Indexed: 10/03/2023]
Abstract
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) have been detected in most aquatic environments worldwide and are referred to as "forever chemicals" because of their extreme chemical and thermal stability. Biofilms, as basic aquatic bioresources, can colonize various substratum surfaces. Biofilms in the aquatic environment have to interact with the ubiquitous PFASs and have significant implications for both their behavior and destiny, which are still poorly understood. Here, we have a preliminary literature exploration of the interaction between PFASs and biofilms in the various aquatic environments and expect to provide some thoughts on further study. In this review, the biosorption properties of biofilms on PFASs and possible mechanisms are presented. The complex impact of PFASs on biofilm systems was further discussed in terms of the composition and electrical charges of extracellular polymeric substances, intracellular microbial communities, and overall contaminant purification functions. Correspondingly, the effects of biofilms on the redistribution of PFASs in the aqueous environment were analyzed. Finally, we propose that biofilm after adsorption of PFASs is a unique ecological niche that not only reflects the contamination level of PFASs in the aquatic environment but also offers a possible "microbial pool" for PFASs biodegradation. We outline existing knowledge gaps and potential future efforts for investigating how PFASs interact with biofilms in aquatic ecosystems.
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Affiliation(s)
- Bin Ji
- School of Civil Engineering, Yantai University, Yantai 264005, PR China.
| | - Yaqian Zhao
- State Key Laboratory of Eco-Hydraulics in Northwest Arid Region, Xi'an University of Technology, Xi'an 710048, PR China; Department of Municipal and Environmental Engineering, School of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi'an 710048, PR China.
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5
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Delage E, Guilbert T, Yates F. Successful 3D imaging of cleared biological samples with light sheet fluorescence microscopy. J Cell Biol 2023; 222:e202307143. [PMID: 37847528 PMCID: PMC10583220 DOI: 10.1083/jcb.202307143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/22/2023] [Accepted: 09/22/2023] [Indexed: 10/18/2023] Open
Abstract
In parallel with the development of tissue-clearing methods, over the last decade, light sheet fluorescence microscopy has contributed to major advances in various fields, such as cell and developmental biology and neuroscience. While biologists are increasingly integrating three-dimensional imaging into their research projects, their experience with the technique is not always up to their expectations. In response to a survey of specific challenges associated with sample clearing and labeling, image acquisition, and data analysis, we have critically assessed the recent literature to characterize the difficulties inherent to light sheet fluorescence microscopy applied to cleared biological samples and to propose solutions to overcome them. This review aims to provide biologists interested in light sheet fluorescence microscopy with a primer for the development of their imaging pipeline, from sample preparation to image analysis. Importantly, we believe that issues could be avoided with better anticipation of image analysis requirements, which should be kept in mind while optimizing sample preparation and acquisition parameters.
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Affiliation(s)
- Elise Delage
- CellTechs Laboratory, SupBiotech, Villejuif, France
- Service d’Etude des Prions et des Infections Atypiques, Institut François Jacob, Commissariat à l’Energie Atomique et aux Energies Alternatives, Université Paris Saclay, Fontenay-aux-Roses, France
| | - Thomas Guilbert
- Institut Cochin, Institut national de la santé et de la recherche médicale (U1016), Centre National de la Recherche Scientifique (UMR 8104), Université de Paris (UMR-S1016), Paris, France
| | - Frank Yates
- CellTechs Laboratory, SupBiotech, Villejuif, France
- Service d’Etude des Prions et des Infections Atypiques, Institut François Jacob, Commissariat à l’Energie Atomique et aux Energies Alternatives, Université Paris Saclay, Fontenay-aux-Roses, France
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6
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Cremin K, Duxbury SJN, Rosko J, Soyer OS. Formation and emergent dynamics of spatially organized microbial systems. Interface Focus 2023; 13:20220062. [PMID: 36789239 PMCID: PMC9912014 DOI: 10.1098/rsfs.2022.0062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/19/2022] [Indexed: 02/12/2023] Open
Abstract
Spatial organization is the norm rather than the exception in the microbial world. While the study of microbial physiology has been dominated by studies in well-mixed cultures, there is now increasing interest in understanding the role of spatial organization in microbial physiology, coexistence and evolution. Where studied, spatial organization has been shown to influence all three of these aspects. In this mini review and perspective article, we emphasize that the dynamics within spatially organized microbial systems (SOMS) are governed by feedbacks between local physico-chemical conditions, cell physiology and movement, and evolution. These feedbacks can give rise to emergent dynamics, which need to be studied through a combination of spatio-temporal measurements and mathematical models. We highlight the initial formation of SOMS and their emergent dynamics as two open areas of investigation for future studies. These studies will benefit from the development of model systems that can mimic natural ones in terms of species composition and spatial structure.
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Affiliation(s)
- Kelsey Cremin
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | | | - Jerko Rosko
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Orkun S. Soyer
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
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Planchette AL, Schmidt C, Burri O, Gomez de Agüero M, Radenovic A, Mylonas A, Extermann J. Optical imaging of the small intestine immune compartment across scales. Commun Biol 2023; 6:352. [PMID: 37002381 PMCID: PMC10066397 DOI: 10.1038/s42003-023-04642-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 02/28/2023] [Indexed: 04/03/2023] Open
Abstract
The limitations of 2D microscopy constrain our ability to observe and understand tissue-wide networks that are, by nature, 3-dimensional. Optical projection tomography (OPT) enables the acquisition of large volumes (ranging from micrometres to centimetres) in various tissues. We present a multi-modal workflow for the characterization of both structural and quantitative parameters of the mouse small intestine. As proof of principle, we evidence its applicability for imaging the mouse intestinal immune compartment and surrounding mucosal structures. We quantify the volumetric size and spatial distribution of Isolated Lymphoid Follicles (ILFs) and quantify the density of villi throughout centimetre-long segments of intestine. Furthermore, we exhibit the age and microbiota dependence for ILF development, and leverage a technique that we call reverse-OPT for identifying and homing in on regions of interest. Several quantification capabilities are displayed, including villous density in the autofluorescent channel and the size and spatial distribution of the signal of interest at millimetre-scale volumes. The concatenation of 3D imaging with reverse-OPT and high-resolution 2D imaging allows accurate localisation of ROIs and adds value to interpretations made in 3D. Importantly, OPT may be used to identify sparsely-distributed regions of interest in large volumes whilst retaining compatibility with high-resolution microscopy modalities, including confocal microscopy. We believe this pipeline to be approachable for a wide-range of specialties, and to provide a new method for characterisation of the mouse intestinal immune compartment.
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Affiliation(s)
- Arielle Louise Planchette
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
| | - Cédric Schmidt
- HEPIA/HES-SO, University of Applied Sciences of Western Switzerland, Rue de la Prairie 4, 1202, Geneva, Switzerland
| | - Olivier Burri
- BioImaging & Optics Platform, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Mercedes Gomez de Agüero
- Host-microbial interactions group, Institute of Systems Immunology, Max Planck research group, University of Würzburg, Würzburg, Germany
- Mucosal Immunology Group, Department for Biomedical Research, University of Bern, Bern, Switzerland
| | - Aleksandra Radenovic
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
| | - Alessio Mylonas
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Jérôme Extermann
- HEPIA/HES-SO, University of Applied Sciences of Western Switzerland, Rue de la Prairie 4, 1202, Geneva, Switzerland
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8
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Xia H, Chen H, Cheng X, Yin M, Yao X, Ma J, Huang M, Chen G, Liu H. Zebrafish: an efficient vertebrate model for understanding role of gut microbiota. Mol Med 2022; 28:161. [PMID: 36564702 PMCID: PMC9789649 DOI: 10.1186/s10020-022-00579-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 11/21/2022] [Indexed: 12/24/2022] Open
Abstract
Gut microbiota plays a critical role in the maintenance of host health. As a low-cost and genetically tractable vertebrate model, zebrafish have been widely used for biological research. Zebrafish and humans share some similarities in intestinal physiology and function, and this allows zebrafish to be a surrogate model for investigating the crosstalk between the gut microbiota and host. Especially, zebrafish have features such as high fecundity, external fertilization, and early optical transparency. These enable the researchers to employ the fish to address questions not easily addressed in other animal models. In this review, we described the intestine structure of zebrafish. Also, we summarized the methods of generating a gnotobiotic zebrafish model, the factors affecting its intestinal flora, and the study progress of gut microbiota functions in zebrafish. Finally, we discussed the limitations and challenges of the zebrafish model for gut microbiota studies. In summary, this review established that zebrafish is an attractive research tool to understand mechanistic insights into host-microbe interaction.
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Affiliation(s)
- Hui Xia
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Huimin Chen
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Xue Cheng
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Mingzhu Yin
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Xiaowei Yao
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Jun Ma
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Mengzhen Huang
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Gang Chen
- Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, 430061, China.
| | - Hongtao Liu
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China.
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9
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BCM3D 2.0: accurate segmentation of single bacterial cells in dense biofilms using computationally generated intermediate image representations. NPJ Biofilms Microbiomes 2022; 8:99. [PMID: 36529755 PMCID: PMC9760640 DOI: 10.1038/s41522-022-00362-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
Accurate detection and segmentation of single cells in three-dimensional (3D) fluorescence time-lapse images is essential for observing individual cell behaviors in large bacterial communities called biofilms. Recent progress in machine-learning-based image analysis is providing this capability with ever-increasing accuracy. Leveraging the capabilities of deep convolutional neural networks (CNNs), we recently developed bacterial cell morphometry in 3D (BCM3D), an integrated image analysis pipeline that combines deep learning with conventional image analysis to detect and segment single biofilm-dwelling cells in 3D fluorescence images. While the first release of BCM3D (BCM3D 1.0) achieved state-of-the-art 3D bacterial cell segmentation accuracies, low signal-to-background ratios (SBRs) and images of very dense biofilms remained challenging. Here, we present BCM3D 2.0 to address this challenge. BCM3D 2.0 is entirely complementary to the approach utilized in BCM3D 1.0. Instead of training CNNs to perform voxel classification, we trained CNNs to translate 3D fluorescence images into intermediate 3D image representations that are, when combined appropriately, more amenable to conventional mathematical image processing than a single experimental image. Using this approach, improved segmentation results are obtained even for very low SBRs and/or high cell density biofilm images. The improved cell segmentation accuracies in turn enable improved accuracies of tracking individual cells through 3D space and time. This capability opens the door to investigating time-dependent phenomena in bacterial biofilms at the cellular level.
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10
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Sundarraman D, Smith TJ, Kast JVZ, Guillemin K, Parthasarathy R. Disaggregation as an interaction mechanism among intestinal bacteria. Biophys J 2022; 121:3458-3473. [PMID: 35982615 PMCID: PMC9515126 DOI: 10.1016/j.bpj.2022.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/22/2022] [Accepted: 08/11/2022] [Indexed: 12/01/2022] Open
Abstract
The gut microbiome contains hundreds of interacting species that together influence host health and development. The mechanisms by which intestinal microbes can interact, however, remain poorly mapped and are often modeled as spatially unstructured competitions for chemical resources. Recent imaging studies examining the zebrafish gut have shown that patterns of aggregation are central to bacterial population dynamics. In this study, we focus on bacterial species of genera Aeromonas and Enterobacter. Two zebrafish gut-derived isolates, Aeromonas ZOR0001 (AE) and Enterobacter ZOR0014 (EN), when mono-associated with the host, are highly aggregated and located primarily in the intestinal midgut. An Aeromonas isolate derived from the commensal strain, Aeromonas-MB4 (AE-MB4), differs from the parental strain in that it is composed mostly of planktonic cells localized to the anterior gut. When challenged by AE-MB4, clusters of EN rapidly fragment into non-motile, slow-growing, dispersed individual cells with overall abundance two orders of magnitude lower than the mono-association value. In the presence of a certain set of additional gut bacterial species, these effects on EN are dampened. In particular, if AE-MB4 invades an already established multi-species community, EN persists in the form of large aggregates. These observations reveal an unanticipated competition mechanism based on manipulation of bacterial spatial organization, namely dissolution of aggregates, and provide evidence that multi-species communities may facilitate stable intestinal co-existence.
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Affiliation(s)
- Deepika Sundarraman
- Department of Physics and Materials Science Institute, University of Oregon, Eugene, Oregon
| | - T Jarrod Smith
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon
| | - Jade V Z Kast
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon
| | - Karen Guillemin
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon; Humans and the Microbiome Program, CIFAR, Toronto, Ontario
| | - Raghuveer Parthasarathy
- Department of Physics and Materials Science Institute, University of Oregon, Eugene, Oregon; Institute of Molecular Biology, University of Oregon, Eugene, Oregon.
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11
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Palma V, Gutiérrez MS, Vargas O, Parthasarathy R, Navarrete P. Methods to Evaluate Bacterial Motility and Its Role in Bacterial–Host Interactions. Microorganisms 2022; 10:microorganisms10030563. [PMID: 35336138 PMCID: PMC8953368 DOI: 10.3390/microorganisms10030563] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/02/2022] [Accepted: 02/06/2022] [Indexed: 11/16/2022] Open
Abstract
Bacterial motility is a widespread characteristic that can provide several advantages for the cell, allowing it to move towards more favorable conditions and enabling host-associated processes such as colonization. There are different bacterial motility types, and their expression is highly regulated by the environmental conditions. Because of this, methods for studying motility under realistic experimental conditions are required. A wide variety of approaches have been developed to study bacterial motility. Here, we present the most common techniques and recent advances and discuss their strengths as well as their limitations. We classify them as macroscopic or microscopic and highlight the advantages of three-dimensional imaging in microscopic approaches. Lastly, we discuss methods suited for studying motility in bacterial–host interactions, including the use of the zebrafish model.
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Affiliation(s)
- Victoria Palma
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
| | - María Soledad Gutiérrez
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
- Millennium Science Initiative Program, Milenium Nucleus in the Biology of the Intestinal Microbiota, National Agency for Research and Development (ANID), Moneda 1375, Santiago 8200000, Chile
| | - Orlando Vargas
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
| | - Raghuveer Parthasarathy
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA;
- Department of Physics and Materials Science Institute, University of Oregon, Eugene, OR 97403, USA
| | - Paola Navarrete
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
- Millennium Science Initiative Program, Milenium Nucleus in the Biology of the Intestinal Microbiota, National Agency for Research and Development (ANID), Moneda 1375, Santiago 8200000, Chile
- Correspondence:
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12
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Bridier A, Briandet R. Microbial Biofilms: Structural Plasticity and Emerging Properties. Microorganisms 2022; 10:138. [PMID: 35056587 PMCID: PMC8778831 DOI: 10.3390/microorganisms10010138] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 01/07/2022] [Indexed: 02/01/2023] Open
Abstract
Microbial biofilms are found everywhere and can be either beneficial or detrimental, as they are involved in crucial ecological processes and in severe chronic infections. The functional properties of biofilms are closely related to their three-dimensional (3D) structure, and the ability of microorganisms to collectively and dynamically shape the community spatial organization in response to stresses in such biological edifices. A large number of works have shown a relationship between the modulation of the spatial organization and ecological interactions in biofilms in response to environmental fluctuations, as well as their emerging properties essential for nutrient cycling and bioremediation processes in natural environments. On the contrary, numerous studies have emphasized the role of structural rearrangements and matrix production in the increased tolerance of bacteria in biofilms toward antimicrobials. In these last few years, the development of innovative approaches, relying on recent technological advances in imaging, computing capacity, and other analytical tools, has led to the production of original data that have improved our understanding of this close relationship. However, it has also highlighted the need to delve deeper into the study of cell behavior in such complex communities during 3D structure development and maturation- from a single-cell to a multicellular scale- to better control or harness positive and negative impacts of biofilms. For this Special Issue, the interplay between biofilm emerging properties and their 3D spatial organization considering different models, from single bacteria to complex environmental communities, and various environments, from natural ecosystems to industrial and medical settings are addressed.
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Affiliation(s)
- Arnaud Bridier
- Antibiotics, Biocides, Residues and Resistance Unit, Fougères Laboratory, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 35300 Fougères, France
| | - Romain Briandet
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
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Liu Y, Patko D, Engelhardt I, George TS, Stanley-Wall NR, Ladmiral V, Ameduri B, Daniell TJ, Holden N, MacDonald MP, Dupuy LX. Plant-environment microscopy tracks interactions of Bacillus subtilis with plant roots across the entire rhizosphere. Proc Natl Acad Sci U S A 2021; 118:e2109176118. [PMID: 34819371 PMCID: PMC8640753 DOI: 10.1073/pnas.2109176118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2021] [Indexed: 11/18/2022] Open
Abstract
Our understanding of plant-microbe interactions in soil is limited by the difficulty of observing processes at the microscopic scale throughout plants' large volume of influence. Here, we present the development of three-dimensional live microscopy for resolving plant-microbe interactions across the environment of an entire seedling growing in a transparent soil in tailor-made mesocosms, maintaining physical conditions for the culture of both plants and microorganisms. A tailor-made, dual-illumination light sheet system acquired photons scattered from the plant while fluorescence emissions were simultaneously captured from transparent soil particles and labeled microorganisms, allowing the generation of quantitative data on samples ∼3,600 mm3 in size, with as good as 5 µm resolution at a rate of up to one scan every 30 min. The system tracked the movement of Bacillus subtilis populations in the rhizosphere of lettuce plants in real time, revealing previously unseen patterns of activity. Motile bacteria favored small pore spaces over the surface of soil particles, colonizing the root in a pulsatile manner. Migrations appeared to be directed toward the root cap, the point of "first contact," before the subsequent colonization of mature epidermis cells. Our findings show that microscopes dedicated to live environmental studies present an invaluable tool to understand plant-microbe interactions.
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Affiliation(s)
- Yangminghao Liu
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, United Kingdom
| | - Daniel Patko
- Ecological Sciences, The James Hutton Institute, Dundee DD2 5DA, United Kingdom
- Department of Conservation of Natural Resources, Neiker, Derio 48160, Spain
| | - Ilonka Engelhardt
- Ecological Sciences, The James Hutton Institute, Dundee DD2 5DA, United Kingdom
- Department of Conservation of Natural Resources, Neiker, Derio 48160, Spain
| | - Timothy S George
- Ecological Sciences, The James Hutton Institute, Dundee DD2 5DA, United Kingdom
| | | | - Vincent Ladmiral
- Institut Charles Gerhardt de Montpellier, Université de Montpellier, CNRS, ENSCM, Montpellier 34090, France
| | - Bruno Ameduri
- Institut Charles Gerhardt de Montpellier, Université de Montpellier, CNRS, ENSCM, Montpellier 34090, France
| | - Tim J Daniell
- Plants, Photosynthesis and Soil, School of Biosciences, The University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Nicola Holden
- Northern Faculty, Scotland's Rural College, Aberdeen AB21 9YA, United Kingdom
| | - Michael P MacDonald
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, United Kingdom;
| | - Lionel X Dupuy
- Ecological Sciences, The James Hutton Institute, Dundee DD2 5DA, United Kingdom;
- Department of Conservation of Natural Resources, Neiker, Derio 48160, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao 48009, Spain
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14
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Zhang J, Zhang M, Wang Y, Donarski E, Gahlmann A. Optically Accessible Microfluidic Flow Channels for Noninvasive High-Resolution Biofilm Imaging Using Lattice Light Sheet Microscopy. J Phys Chem B 2021; 125:12187-12196. [PMID: 34714647 DOI: 10.1021/acs.jpcb.1c07759] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Imaging platforms that enable long-term, high-resolution imaging of biofilms are required to study cellular level dynamics within bacterial biofilms. By combining high spatial and temporal resolution and low phototoxicity, lattice light sheet microscopy (LLSM) has made critical contributions to the study of cellular dynamics. However, the power of LLSM has not yet been leveraged for biofilm research because the open-on-top imaging geometry using water-immersion objective lenses is not compatible with living bacterial specimens; bacterial growth on the microscope's objective lenses makes long-term time-lapse imaging impossible and raises considerable safety concerns for microscope users. To make LLSM compatible with pathogenic bacterial specimens, we developed hermetically sealed, but optically accessible, microfluidic flow channels that can sustain bacterial biofilm growth for multiple days under precisely controllable physical and chemical conditions. To generate a liquid- and gas-tight seal, we glued a thin polymer film across a 3D-printed channel, where the top wall had been omitted. We achieved negligible optical aberrations by using polymer films that precisely match the refractive index of water. Bacteria do not adhere to the polymer film itself, so that the polymer window provides unobstructed optical access to the channel interior. Inside the flow channels, biofilms can be grown on arbitrary, even nontransparent, surfaces. By integrating this flow channel with LLSM, we were able to record the growth of S. oneidensis MR-1 biofilms over several days at cellular resolution without any observable phototoxicity or photodamage.
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Affiliation(s)
- Ji Zhang
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Mingxing Zhang
- School of Materials Science and Engineering, Northeastern University, Shenyang, Liaoning 110819, China
| | - Yibo Wang
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Eric Donarski
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Andreas Gahlmann
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States.,Department of Molecular Physiology & Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22903, United States
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15
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Schlomann BH, Parthasarathy R. Gut bacterial aggregates as living gels. eLife 2021; 10:71105. [PMID: 34490846 PMCID: PMC8514234 DOI: 10.7554/elife.71105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 09/06/2021] [Indexed: 11/28/2022] Open
Abstract
The spatial organization of gut microbiota influences both microbial abundances and host-microbe interactions, but the underlying rules relating bacterial dynamics to large-scale structure remain unclear. To this end, we studied experimentally and theoretically the formation of three-dimensional bacterial clusters, a key parameter controlling susceptibility to intestinal transport and access to the epithelium. Inspired by models of structure formation in soft materials, we sought to understand how the distribution of gut bacterial cluster sizes emerges from bacterial-scale kinetics. Analyzing imaging-derived data on cluster sizes for eight different bacterial strains in the larval zebrafish gut, we find a common family of size distributions that decay approximately as power laws with exponents close to −2, becoming shallower for large clusters in a strain-dependent manner. We show that this type of distribution arises naturally from a Yule-Simons-type process in which bacteria grow within clusters and can escape from them, coupled to an aggregation process that tends to condense the system toward a single massive cluster, reminiscent of gel formation. Together, these results point to the existence of general, biophysical principles governing the spatial organization of the gut microbiome that may be useful for inferring fast-timescale dynamics that are experimentally inaccessible. The human gut is home to vast numbers of bacteria that grow, compete and cooperate in a dynamic, densely packed space. The spatial arrangement of organisms – for example, if they are clumped together or broadly dispersed – plays a major role in all ecosystems; but how bacteria are organized in the human gut remains mysterious and difficult to investigate. Zebrafish larvae provide a powerful tool for studying microbes in the gut, as they are optically transparent and anatomically similar to other vertebrates, including humans. Furthermore, zebrafish can be easily manipulated so that one species of bacteria can be studied at a time. To investigate whether individual bacterial species are arranged in similar ways, Scholmann and Parthasarathy exposed zebrafish with no gut bacteria to one of eight different strains. Each species was then monitored using three-dimensional microscopy to see how the population shaped itself into clusters (or colonies). Schlomann and Parthasarathy used this data to build a mathematical model that can predict the size of the clusters formed by different gut bacteria. This revealed that the spatial arrangement of each species depended on the same biological processes: bacterial growth, aggregation and fragmentation of clusters, and expulsion from the gut. These new details about how bacteria are organized in zebrafish may help scientists learn more about gut health in humans. Although it is not possible to peer into the human gut and watch how bacteria behave, scientists could use the same analysis method to study the size of bacterial colonies in fecal samples. This may provide further clues about how microbes are spatially arranged in the human gut and the biological processes underlying this formation.
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Affiliation(s)
- Brandon H Schlomann
- Department of Physics, Institute of Molecular Biology, and Materials Science Institute, University of Oregon, Eugene, United States.,Department of Physics and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Raghuveer Parthasarathy
- Department of Physics, Institute of Molecular Biology, and Materials Science Institute, University of Oregon, Eugene, United States
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16
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Skaar EP. Imaging Infection Across Scales of Size: From Whole Animals to Single Molecules. Annu Rev Microbiol 2021; 75:407-426. [PMID: 34343016 DOI: 10.1146/annurev-micro-041521-121457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Infectious diseases are a leading cause of global morbidity and mortality, and the threat of infectious diseases to human health is steadily increasing as new diseases emerge, existing diseases reemerge, and antimicrobial resistance expands. The application of imaging technology to the study of infection biology has the potential to uncover new factors that are critical to the outcome of host-pathogen interactions and to lead to innovations in diagnosis and treatment of infectious diseases. This article reviews current and future opportunities for the application of imaging to the study of infectious diseases, with a particular focus on the power of imaging objects across a broad range of sizes to expand the utility of these approaches. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Eric P Skaar
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA;
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17
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Impens F, Dussurget O. Three decades of listeriology through the prism of technological advances. Cell Microbiol 2021; 22:e13183. [PMID: 32185895 DOI: 10.1111/cmi.13183] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/28/2020] [Accepted: 01/29/2020] [Indexed: 12/15/2022]
Abstract
Decades of breakthroughs resulting from cross feeding of microbiological research and technological innovation have promoted Listeria monocytogenes to the rank of model microorganism to study host-pathogen interactions. The extraordinary capacity of this bacterium to interfere with a vast array of host cellular processes uncovered new concepts in microbiology, cell biology and infection biology. Here, we review technological advances that revealed how bacteria and host interact in space and time at the molecular, cellular, tissue and whole body scales, ultimately revolutionising our understanding of Listeria pathogenesis. With the current bloom of multidisciplinary integrative approaches, Listeria entered a new microbiology era.
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Affiliation(s)
- Francis Impens
- Center for Medical Biotechnology, VIB, Ghent, Belgium.,Department for Biomedical Medicine, Ghent University, Ghent, Belgium.,VIB Proteomics Core, VIB, Ghent, Belgium
| | - Olivier Dussurget
- Institut Pasteur, Unité de Recherche Yersinia, Paris, France.,Université de Paris, Sorbonne Paris Cité, Paris, France
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18
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Ishikawa T, Omori T, Kikuchi K. Bacterial biomechanics-From individual behaviors to biofilm and the gut flora. APL Bioeng 2020; 4:041504. [PMID: 33163845 PMCID: PMC7595747 DOI: 10.1063/5.0026953] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/16/2020] [Indexed: 02/07/2023] Open
Abstract
Bacteria inhabit a variety of locations and play important roles in the environment and health. Our understanding of bacterial biomechanics has improved markedly in the last decade and has revealed that biomechanics play a significant role in microbial biology. The obtained knowledge has enabled investigation of complex phenomena, such as biofilm formation and the dynamics of the gut flora. A bottom-up strategy, i.e., from the cellular to the macroscale, facilitates understanding of macroscopic bacterial phenomena. In this Review, we first cover the biomechanics of individual bacteria in the bulk liquid and on surfaces as the base of complex phenomena. The collective behaviors of bacteria in simple environments are next introduced. We then introduce recent advances in biofilm biomechanics, in which adhesion force and the flow environment play crucial roles. We also review transport phenomena in the intestine and the dynamics of the gut flora, focusing on that in zebrafish. Finally, we provide an overview of the future prospects for the field.
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Affiliation(s)
| | - Toshihiro Omori
- Department Finemechanics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
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19
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Koch C, Kuchenbuch A, Marosvölgyi M, Weisshart K, Harnisch F. Label‐Free Four‐Dimensional Visualization of Anaerobically Growing Electroactive Biofilms. Cytometry A 2020; 97:737-741. [DOI: 10.1002/cyto.a.24169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 05/29/2020] [Accepted: 06/02/2020] [Indexed: 01/27/2023]
Affiliation(s)
- Christin Koch
- Department of Environmental MicrobiologyHelmholtz Center for Environmental Research GmbH – UFZ Permoserstraße 15, Leipzig 04318 Germany
| | - Anne Kuchenbuch
- Department of Environmental MicrobiologyHelmholtz Center for Environmental Research GmbH – UFZ Permoserstraße 15, Leipzig 04318 Germany
| | | | - Klaus Weisshart
- Carl Zeiss Microscopy GmbH Carl‐Zeiss‐Promenade 10, Jena 07745 Germany
| | - Falk Harnisch
- Department of Environmental MicrobiologyHelmholtz Center for Environmental Research GmbH – UFZ Permoserstraße 15, Leipzig 04318 Germany
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20
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Swimming motility of a gut bacterial symbiont promotes resistance to intestinal expulsion and enhances inflammation. PLoS Biol 2020; 18:e3000661. [PMID: 32196484 PMCID: PMC7112236 DOI: 10.1371/journal.pbio.3000661] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/01/2020] [Accepted: 02/24/2020] [Indexed: 01/07/2023] Open
Abstract
Some of the densest microbial ecosystems in nature thrive within the intestines of humans and other animals. To protect mucosal tissues and maintain immune tolerance, animal hosts actively sequester bacteria within the intestinal lumen. In response, numerous bacterial pathogens and pathobionts have evolved strategies to subvert spatial restrictions, thereby undermining immune homeostasis. However, in many cases, it is unclear how escaping host spatial control benefits gut bacteria and how changes in intestinal biogeography are connected to inflammation. A better understanding of these processes could uncover new targets for treating microbiome-mediated inflammatory diseases. To this end, we investigated the spatial organization and dynamics of bacterial populations within the intestine using larval zebrafish and live imaging. We discovered that a proinflammatory Vibrio symbiont native to zebrafish governs its own spatial organization using swimming motility and chemotaxis. Surprisingly, we found that Vibrio’s motile behavior does not enhance its growth rate but rather promotes its persistence by enabling it to counter intestinal flow. In contrast, Vibrio mutants lacking motility traits surrender to host spatial control, becoming aggregated and entrapped within the lumen. Consequently, nonmotile and nonchemotactic mutants are susceptible to intestinal expulsion and experience large fluctuations in absolute abundance. Further, we found that motile Vibrio cells induce expression of the proinflammatory cytokine tumor necrosis factor alpha (TNFα) in gut-associated macrophages and the liver. Using inducible genetic switches, we demonstrate that swimming motility can be manipulated in situ to modulate the spatial organization, persistence, and inflammatory activity of gut bacterial populations. Together, our findings suggest that host spatial control over resident microbiota plays a broader role in regulating the abundance and persistence of gut bacteria than simply protecting mucosal tissues. Moreover, we show that intestinal flow and bacterial motility are potential targets for therapeutically managing bacterial spatial organization and inflammatory activity within the gut. The use of live imaging and bacteria engineered to carry inducible genetic switches reveals how a gut symbiont uses swimming motility to escape the host's spatial control and persist within the physically dynamic confines of the intestine.
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21
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Sankaran J, Tan NJHJ, But KP, Cohen Y, Rice SA, Wohland T. Single microcolony diffusion analysis in Pseudomonas aeruginosa biofilms. NPJ Biofilms Microbiomes 2019; 5:35. [PMID: 31728202 PMCID: PMC6841743 DOI: 10.1038/s41522-019-0107-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 10/04/2019] [Indexed: 01/25/2023] Open
Abstract
The influence of the biofilm matrix on molecular diffusion is commonly hypothesized to be responsible for emergent characteristics of biofilms such as nutrient trapping, signal accumulation and antibiotic tolerance. Hence quantifying the molecular diffusion coefficient is important to determine whether there is an influence of biofilm microenvironment on the mobility of molecules. Here, we use single plane illumination microscopy fluorescence correlation spectroscopy (SPIM-FCS) to obtain 3D diffusion coefficient maps with micrometre spatial and millisecond temporal resolution of entire Pseudomonas aeruginosa microcolonies. We probed how molecular properties such as size and charge as well as biofilm properties such as microcolony size and depth influence diffusion of fluorescently labelled dextrans inside biofilms. The 2 MDa dextran showed uneven penetration and a reduction in diffusion coefficient suggesting that the biofilm acts as a molecular sieve. Its diffusion coefficient was negatively correlated with the size of the microcolony. Positively charged dextran molecules and positively charged antibiotic tobramycin preferentially partitioned into the biofilm and remained mobile inside the microcolony, albeit with a reduced diffusion coefficient. Lastly, we measured changes of diffusion upon induction of dispersal and detected an increase in diffusion coefficient inside the biofilm before any loss of biomass. Thus, the change in diffusion is a proxy to detect early stages of dispersal. Our work shows that 3D diffusion maps are very sensitive to physiological changes in biofilms, viz. dispersal. However, this study also shows that diffusion, as mediated by the biofilm matrix, does not account for the high level of antibiotic tolerance associated with biofilms.
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Affiliation(s)
- Jagadish Sankaran
- 1Department of Biological Sciences, National University of Singapore, 117558 Singapore, Singapore.,2Centre for BioImaging Sciences, National University of Singapore, 117557 Singapore, Singapore
| | - Nicholas J H J Tan
- 3Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551 Singapore, Singapore.,4School of Biological Sciences, Nanyang Technological University, 637551 Singapore, Singapore
| | - Ka Pui But
- 2Centre for BioImaging Sciences, National University of Singapore, 117557 Singapore, Singapore.,5Department of Chemistry, National University of Singapore, 117543 Singapore, Singapore
| | - Yehuda Cohen
- 3Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551 Singapore, Singapore.,4School of Biological Sciences, Nanyang Technological University, 637551 Singapore, Singapore
| | - Scott A Rice
- 3Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551 Singapore, Singapore.,4School of Biological Sciences, Nanyang Technological University, 637551 Singapore, Singapore.,6ithree Institute, University of Technology Sydney, Sydney, Australia
| | - Thorsten Wohland
- 1Department of Biological Sciences, National University of Singapore, 117558 Singapore, Singapore.,2Centre for BioImaging Sciences, National University of Singapore, 117557 Singapore, Singapore.,5Department of Chemistry, National University of Singapore, 117543 Singapore, Singapore
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22
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Cattò C, Cappitelli F. Testing Anti-Biofilm Polymeric Surfaces: Where to Start? Int J Mol Sci 2019; 20:E3794. [PMID: 31382580 PMCID: PMC6696330 DOI: 10.3390/ijms20153794] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 08/02/2019] [Indexed: 12/11/2022] Open
Abstract
Present day awareness of biofilm colonization on polymeric surfaces has prompted the scientific community to develop an ever-increasing number of new materials with anti-biofilm features. However, compared to the large amount of work put into discovering potent biofilm inhibitors, only a small number of papers deal with their validation, a critical step in the translation of research into practical applications. This is due to the lack of standardized testing methods and/or of well-controlled in vivo studies that show biofilm prevention on polymeric surfaces; furthermore, there has been little correlation with the reduced incidence of material deterioration. Here an overview of the most common methods for studying biofilms and for testing the anti-biofilm properties of new surfaces is provided.
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Affiliation(s)
- Cristina Cattò
- Department of Food Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy
| | - Francesca Cappitelli
- Department of Food Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy.
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23
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Schlomann BH, Parthasarathy R. Timescales of gut microbiome dynamics. Curr Opin Microbiol 2019; 50:56-63. [PMID: 31689582 PMCID: PMC6899164 DOI: 10.1016/j.mib.2019.09.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/19/2019] [Accepted: 09/23/2019] [Indexed: 02/07/2023]
Abstract
Vast communities of microorganisms inhabit the gastrointestinal tracts of humans and other animals. Understanding their initial development, fluctuations in composition, stability over long times, and responses to transient perturbations - in other words their dynamics - is important both for gaining basic insights into these ecosystems and for rationally manipulating them for therapeutic ends. Gut microbiome dynamics, however, remain poorly understood. We review here studies of gut microbiome dynamics in the presence and absence of external perturbations, noting especially the long timescales associated with overall stability and the short timescales associated with various underlying biological processes. Integrating these disparate timescales, we suggest, is an important goal for future work and is necessary for developing a predictive understanding of microbiome dynamics.
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Affiliation(s)
- Brandon H Schlomann
- Department of Physics, Materials Science Institute, and Institute of Molecular Biology, University of Oregon, Eugene, OR, United States
| | - Raghuveer Parthasarathy
- Department of Physics, Materials Science Institute, and Institute of Molecular Biology, University of Oregon, Eugene, OR, United States.
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24
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Wiles TJ, Guillemin K. The Other Side of the Coin: What Beneficial Microbes Can Teach Us about Pathogenic Potential. J Mol Biol 2019; 431:2946-2956. [PMID: 31078557 DOI: 10.1016/j.jmb.2019.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/19/2019] [Accepted: 05/01/2019] [Indexed: 02/07/2023]
Abstract
Koch's postulates and molecular Koch's postulates have made an indelible mark on how we study and classify microbes, particularly pathogens. However, rigid adherence to these historic postulates constrains our view of not only microbial pathogenesis but also host-microbe relationships in general. Collectively, the postulates imply that a "microbial pathogen" is a clearly identifiable organism with the exclusive capacity to elicit disease through an arsenal of pathogen-specific "virulence factors." This narrow definition has been repeatedly contradicted. Advances in DNA sequencing technologies and new experimental systems have revealed that the outcomes of host-microbe interactions are highly contextual and dynamic, especially those involving resident microbiota and variable aspects of host biology. Clarifying what differentiates pathogenic from non-pathogenic microbes, including their paradoxical ability to masquerade as one another, is critical to developing targeted diagnostics and treatments for infectious disease. Such endeavors will also inform the design of therapeutic strategies based on microbiome engineering by providing insights into how manipulating entire host-microbe systems may directly or indirectly alter the pathogenic potential of microbial communities. With these goals in mind, we discuss the need to develop experimental models that better capture the contexts that determine the nature of host-microbe relationships. To demonstrate the potential of one such model-the zebrafish and its resident microbiota-we describe recent work that has revealed the thin line between pathogenic and mutualistic relationships, how the intestine physically shapes bacterial populations and inflammation, and the ability of microbial transmission to override the host's innate immune system.
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Affiliation(s)
- Travis J Wiles
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
| | - Karen Guillemin
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA; Humans and the Microbiome Program, CIFAR, Toronto, Ontario, Canada.
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25
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Logan SL, Dudley C, Baker RP, Taormina MJ, Hay EA, Parthasarathy R. Automated high-throughput light-sheet fluorescence microscopy of larval zebrafish. PLoS One 2018; 13:e0198705. [PMID: 30427839 PMCID: PMC6235235 DOI: 10.1371/journal.pone.0198705] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 10/23/2018] [Indexed: 12/21/2022] Open
Abstract
Light sheet fluorescence microscopy enables fast, minimally phototoxic, three-dimensional imaging of live specimens, but is currently limited by low throughput and tedious sample preparation. Here, we describe an automated high-throughput light sheet fluorescence microscope in which specimens are positioned by and imaged within a fluidic system integrated with the sheet excitation and detection optics. We demonstrate the ability of the instrument to rapidly examine live specimens with minimal manual intervention by imaging fluorescent neutrophils over a nearly 0.3 mm3 volume in dozens of larval zebrafish. In addition to revealing considerable inter-individual variability in neutrophil number, known previously from labor-intensive methods, three-dimensional imaging allows assessment of the correlation between the bulk measure of total cellular fluorescence and the spatially resolved measure of actual neutrophil number per animal. We suggest that our simple experimental design should considerably expand the scope and impact of light sheet imaging in the life sciences.
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Affiliation(s)
- Savannah L. Logan
- Materials Science Institute, Institute of Molecular Biology, and Department of Physics, The University of Oregon, Eugene, OR, United States of America
| | - Christopher Dudley
- Materials Science Institute, Institute of Molecular Biology, and Department of Physics, The University of Oregon, Eugene, OR, United States of America
| | - Ryan P. Baker
- Materials Science Institute, Institute of Molecular Biology, and Department of Physics, The University of Oregon, Eugene, OR, United States of America
| | - Michael J. Taormina
- Materials Science Institute, Institute of Molecular Biology, and Department of Physics, The University of Oregon, Eugene, OR, United States of America
| | - Edouard A. Hay
- Materials Science Institute, Institute of Molecular Biology, and Department of Physics, The University of Oregon, Eugene, OR, United States of America
| | - Raghuveer Parthasarathy
- Materials Science Institute, Institute of Molecular Biology, and Department of Physics, The University of Oregon, Eugene, OR, United States of America
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