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Hardo G, Li R, Bakshi S. Quantitative microbiology with widefield microscopy: navigating optical artefacts for accurate interpretations. NPJ IMAGING 2024; 2:26. [PMID: 39234390 PMCID: PMC11368818 DOI: 10.1038/s44303-024-00024-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Accepted: 06/21/2024] [Indexed: 09/06/2024]
Abstract
Time-resolved live-cell imaging using widefield microscopy is instrumental in quantitative microbiology research. It allows researchers to track and measure the size, shape, and content of individual microbial cells over time. However, the small size of microbial cells poses a significant challenge in interpreting image data, as their dimensions approache that of the microscope's depth of field, and they begin to experience significant diffraction effects. As a result, 2D widefield images of microbial cells contain projected 3D information, blurred by the 3D point spread function. In this study, we employed simulations and targeted experiments to investigate the impact of diffraction and projection on our ability to quantify the size and content of microbial cells from 2D microscopic images. This study points to some new and often unconsidered artefacts resulting from the interplay of projection and diffraction effects, within the context of quantitative microbiology. These artefacts introduce substantial errors and biases in size, fluorescence quantification, and even single-molecule counting, making the elimination of these errors a complex task. Awareness of these artefacts is crucial for designing strategies to accurately interpret micrographs of microbes. To address this, we present new experimental designs and machine learning-based analysis methods that account for these effects, resulting in accurate quantification of microbiological processes.
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Affiliation(s)
- Georgeos Hardo
- Department of Engineering, University of Cambridge, Cambridge, UK
| | - Ruizhe Li
- Department of Engineering, University of Cambridge, Cambridge, UK
| | - Somenath Bakshi
- Department of Engineering, University of Cambridge, Cambridge, UK
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2
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Barbotin A, Billaudeau C, Sezgin E, Carballido-López R. Quantification of membrane fluidity in bacteria using TIR-FCS. Biophys J 2024; 123:2484-2495. [PMID: 38877702 PMCID: PMC11365102 DOI: 10.1016/j.bpj.2024.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 05/28/2024] [Accepted: 06/10/2024] [Indexed: 06/16/2024] Open
Abstract
Plasma membrane fluidity is an important phenotypic feature that regulates the diffusion, function, and folding of transmembrane and membrane-associated proteins. In bacterial cells, variations in membrane fluidity are known to affect respiration, transport, and antibiotic resistance. Membrane fluidity must therefore be tightly regulated to adapt to environmental variations and stresses such as temperature fluctuations or osmotic shocks. Quantitative investigation of bacterial membrane fluidity has been, however, limited due to the lack of available tools, primarily due to the small size and membrane curvature of bacteria that preclude most conventional analysis methods used in eukaryotes. Here, we develop an assay based on total internal reflection-fluorescence correlation spectroscopy (TIR-FCS) to directly measure membrane fluidity in live bacteria via the diffusivity of fluorescent membrane markers. With simulations validated by experiments, we could determine how the small size, high curvature, and geometry of bacteria affect diffusion measurements and correct subsequent measurements for unbiased diffusion coefficient estimation. We used this assay to quantify the fluidity of the cytoplasmic membranes of the Gram-positive bacteria Bacillus subtilis (rod-shaped) and Staphylococcus aureus (coccus) at high (37°C) and low (20°C) temperatures in a steady state and in response to a cold shock, caused by a shift from high to low temperature. The steady-state fluidity was lower at 20°C than at 37°C, yet differed between B. subtilis and S. aureus at 37°C. Upon cold shock, the membrane fluidity decreased further below the steady-state fluidity at 20°C and recovered within 30 min in both bacterial species. Our minimally invasive assay opens up exciting perspectives for the study of a wide range of phenomena affecting the bacterial membrane, from disruption by chemicals or antibiotics to viral infection or change in nutrient availability.
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Affiliation(s)
- Aurélien Barbotin
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France.
| | - Cyrille Billaudeau
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Erdinc Sezgin
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden
| | - Rut Carballido-López
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France.
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3
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Wu Z, Deng B, Zhou Y, Xie H, Zhang Y, Lin L, Ye J. Non-Invasive Detection, Precise Localization, and Perioperative Navigation of In Vivo Deep Lesions Using Transmission Raman Spectroscopy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301721. [PMID: 37340601 PMCID: PMC10460859 DOI: 10.1002/advs.202301721] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/20/2023] [Indexed: 06/22/2023]
Abstract
Non-invasive detection and precise localization of deep lesions have attracted significant attention for both fundamental and clinical studies. Optical modality techniques are promising with high sensitivity and molecular specificity, but are limited by shallow tissue penetration and the failure to accurately determine lesion depth. Here the authors report in vivo ratiometric surface-enhanced transmission Raman spectroscopy (SETRS) for non-invasive localization and perioperative surgery navigation of deep sentinel lymph nodes in live rats. The SETRS system uses ultrabright surface-enhanced Raman spectroscopy (SERS) nanoparticles with a low detection limit of 10 pM and a home-built photosafe transmission Raman spectroscopy setup. The ratiometric SETRS strategy is proposed based on the ratio of multiple Raman spectral peaks for obtaining lesion depth. Via this strategy, the depth of the phantom lesions in ex vivo rat tissues is precisely determined with a mean-absolute-percentage-error of 11.8%, and the accurate localization of a 6-mm-deep rat popliteal lymph node is achieved. The feasibility of ratiometric SETRS allows the successful perioperative navigation of in vivo lymph node biopsy surgery in live rats under clinically safe laser irradiance. This study represents a significant step toward the clinical translation of TRS techniques, providing new insights for the design and implementation of in vivo SERS applications.
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Affiliation(s)
- Zongyu Wu
- State Key Laboratory of Systems Medicine for Cancer, School of biomedical engineeringShanghai Jiao Tong UniversityShanghai200030P. R. China
| | - Binge Deng
- State Key Laboratory of Systems Medicine for Cancer, School of biomedical engineeringShanghai Jiao Tong UniversityShanghai200030P. R. China
| | - Yutong Zhou
- State Key Laboratory of Systems Medicine for Cancer, School of biomedical engineeringShanghai Jiao Tong UniversityShanghai200030P. R. China
| | - Haoqiang Xie
- State Key Laboratory of Systems Medicine for Cancer, School of biomedical engineeringShanghai Jiao Tong UniversityShanghai200030P. R. China
| | - Yumin Zhang
- State Key Laboratory of Systems Medicine for Cancer, School of biomedical engineeringShanghai Jiao Tong UniversityShanghai200030P. R. China
| | - Li Lin
- State Key Laboratory of Systems Medicine for Cancer, School of biomedical engineeringShanghai Jiao Tong UniversityShanghai200030P. R. China
| | - Jian Ye
- State Key Laboratory of Systems Medicine for Cancer, School of biomedical engineeringShanghai Jiao Tong UniversityShanghai200030P. R. China
- Institute of Medical RoboticsShanghai Jiao Tong UniversityShanghai200240P. R. China
- Shanghai Key Laboratory of Gynecologic Oncology, Ren Ji Hospital, School of MedicineShanghai Jiao Tong UniversityShanghai200127P. R. China
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4
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Kapil K, Xu S, Lee I, Murata H, Kwon SJ, Dordick JS, Matyjaszewski K. Highly Sensitive Detection of Bacteria by Binder-Coupled Multifunctional Polymeric Dyes. Polymers (Basel) 2023; 15:2723. [PMID: 37376368 DOI: 10.3390/polym15122723] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Infectious diseases caused by pathogens are a health burden, but traditional pathogen identification methods are complex and time-consuming. In this work, we have developed well-defined, multifunctional copolymers with rhodamine B dye synthesized by atom transfer radical polymerization (ATRP) using fully oxygen-tolerant photoredox/copper dual catalysis. ATRP enabled the efficient synthesis of copolymers with multiple fluorescent dyes from a biotin-functionalized initiator. Biotinylated dye copolymers were conjugated to antibody (Ab) or cell-wall binding domain (CBD), resulting in a highly fluorescent polymeric dye-binder complex. We showed that the unique combination of multifunctional polymeric dyes and strain-specific Ab or CBD exhibited both enhanced fluorescence and target selectivity for bioimaging of Staphylococcus aureus by flow cytometry and confocal microscopy. The ATRP-derived polymeric dyes have the potential as biosensors for the detection of target DNA, protein, or bacteria, as well as bioimaging.
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Affiliation(s)
- Kriti Kapil
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Shirley Xu
- Department of Chemical and Biological Engineering, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Inseon Lee
- Department of Chemical and Biological Engineering, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Hironobu Murata
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Seok-Joon Kwon
- Department of Chemical and Biological Engineering, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Jonathan S Dordick
- Department of Chemical and Biological Engineering, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Krzysztof Matyjaszewski
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
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5
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Abstract
Micro-/nanorobots (MNRs) can be autonomously propelled on demand in complex biological environments and thus may bring revolutionary changes to biomedicines. Fluorescence has been widely used in real-time imaging, chemo-/biosensing, and photo-(chemo-) therapy. The integration of MNRs with fluorescence generates fluorescent MNRs with unique advantages of optical trackability, on-the-fly environmental sensitivity, and targeting chemo-/photon-induced cytotoxicity. This review provides an up-to-date overview of fluorescent MNRs. After the highlighted elucidation about MNRs of various propulsion mechanisms and the introductory information on fluorescence with emphasis on the fluorescent mechanisms and materials, we systematically illustrate the design and preparation strategies to integrate MNRs with fluorescent substances and their biomedical applications in imaging-guided drug delivery, intelligent on-the-fly sensing and photo-(chemo-) therapy. In the end, we summarize the main challenges and provide an outlook on the future directions of fluorescent MNRs. This work is expected to attract and inspire researchers from different communities to advance the creation and practical application of fluorescent MNRs on a broad horizon.
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Affiliation(s)
- Manyi Yang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, P. R. China
| | - Xia Guo
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, P. R. China
| | - Fangzhi Mou
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, P. R. China
| | - Jianguo Guan
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, P. R. China
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Ondzighi‐Assoume CA, Bhusal B, Traore AM, Ouma WK, Mmbaga MT, Swiggart EM. Efficient fluorescence-based localization technique for real-time tracking endophytes route in host-plants colonization. PLANT DIRECT 2022; 6:e427. [PMID: 35959216 PMCID: PMC9360559 DOI: 10.1002/pld3.427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 06/01/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
Bacterial isolates that enhance plant growth and suppress plant pathogens growth are essential tools for reducing pesticide applications in plant production systems. The objectives of this study were to develop a reliable fluorescence-based technique for labeling bacterial isolates selected as biological control agents (BCAs) to allow their direct tracking in the host-plant interactions, understand the BCA localization within their host plants, and the route of plant colonization. Objectives were achieved by developing competent BCAs transformed with two plasmids, pBSU101 and pANIC-10A, containing reporter genes eGFP and pporRFP, respectively. Our results revealed that the plasmid-mediated transformation efficiencies of antibiotic-resistant competent BCAs identified as PSL, IMC8, and PS were up 84%. Fluorescent BCA-tagged reporter genes were associated with roots and hypocotyls but not with leaves or stems and were confirmed by fluoresence microscopy and PCR analyses in colonized Arabidopsis and sorghum. This fluorescence-based technique's high resolution and reproducibility make it a platform-independent system that allows tracking of BCAs spatially within plant tissues, enabling assessment of the movement and niches of BCAs within colonized plants. Steps for producing and transforming competent fluorescent BCAs, as well as the inoculation of plants with transformed BCAs, localization, and confirmation of fluorescent BCAs through fluorescence imaging and PCR, are provided in this manuscript. This study features host-plant interactions and subsequently biological and physiological mechanisms implicated in these interactions. The maximum time to complete all the steps of this protocol is approximately 3 months.
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Affiliation(s)
- Christine A. Ondzighi‐Assoume
- College of Agriculture, Department of Agricultural and Environmental SciencesTennessee State UniversityNashvilleTennesseeUSA
| | - Bandana Bhusal
- College of Agriculture, Department of Agricultural and Environmental SciencesTennessee State UniversityNashvilleTennesseeUSA
| | - Adam M. Traore
- College of Agriculture, Department of Agricultural and Environmental SciencesTennessee State UniversityNashvilleTennesseeUSA
| | - Wilson K. Ouma
- Department of Entomology and Plant PathologyThe University of TennesseeKnoxvilleTennesseeUSA
| | - Margaret T. Mmbaga
- College of Agriculture, Department of Agricultural and Environmental SciencesTennessee State UniversityNashvilleTennesseeUSA
| | - Ethan M. Swiggart
- College of Agriculture, Department of Agricultural and Environmental SciencesTennessee State UniversityNashvilleTennesseeUSA
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7
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Wang X, Wang T, Chen X, Law J, Shan G, Tang W, Gong Z, Pan P, Liu X, Yu J, Ru C, Huang X, Sun Y. Microrobotic Swarms for Intracellular Measurement with Enhanced Signal-to-Noise Ratio. ACS NANO 2022; 16:10824-10839. [PMID: 35786860 DOI: 10.1021/acsnano.2c02938] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In cell biology, fluorescent dyes are routinely used for biochemical measurements. The traditional global dye treatment method suffers from low signal-to-noise ratios (SNR), especially when used for detecting a low concentration of ions, and increasing the concentration of fluorescent dyes causes more severe cytotoxicity. Here, we report a robotic technique that controls how a low amount of fluorescent-dye-coated magnetic nanoparticles accurately forms a swarm and increases the fluorescent dye concentration in a local region inside a cell for intracellular measurement. Different from existing magnetic micromanipulation systems that generate large swarms (several microns and above) or that cannot move the generated swarm to an arbitrary position, our system is capable of generating a small swarm (e.g., 1 μm) and accurately positioning the swarm inside a single cell (position control accuracy: 0.76 μm). In experiments, the generated swarm inside the cell showed an SNR 10 times higher than the traditional global dye treatment method. The high-SNR robotic swarm enabled intracellular measurements that had not been possible to achieve with traditional global dye treatment. The robotic swarm technique revealed an apparent pH gradient in a migrating cell and was used to measure the intracellular apparent pH in a single oocyte of living C. elegans. With the position control capability, the swarm was also applied to measure calcium changes at the perinuclear region of a cell before and after mechanical stimulation. The results showed a significant calcium increase after mechanical stimulation, and the calcium increase was regulated by the mechanically sensitive ion channel, PIEZO1.
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Affiliation(s)
- Xian Wang
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
- Program in Developmental and Stem Cell Biology and Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - Tiancong Wang
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
| | - Xin Chen
- Program in Developmental and Stem Cell Biology and Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - Junhui Law
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
| | - Guanqiao Shan
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
| | - Wentian Tang
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
| | - Zheyuan Gong
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
| | - Peng Pan
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
- Department of Mechanical Engineering, McGill University, Montreal H3A 0C3, Canada
| | - Xinyu Liu
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto M5S 3G9, Canada
| | - Jiangfan Yu
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen 518172, China
- Shenzhen Institute of Artificial Intelligence and Robotics for Society (AIRS), Shenzhen 518172, China
| | - Changhai Ru
- School of Electronic and Information Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Xi Huang
- Program in Developmental and Stem Cell Biology and Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto M5G 1X8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto M5S 3G9, Canada
- Department of Electrical and Computer Engineering, University of Toronto, Toronto M5S 3G4, Canada
- Department of Computer Science, University of Toronto, Toronto M5S 3G4, Canada
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8
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Revealing bacterial cell biology using cryo-electron tomography. Curr Opin Struct Biol 2022; 75:102419. [PMID: 35820259 DOI: 10.1016/j.sbi.2022.102419] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 11/21/2022]
Abstract
Visualizing macromolecules inside bacteria at a high spatial resolution has remained a challenge owing to their small size and limited resolution of optical microscopy techniques. Recent advances in cryo-electron tomography (cryo-ET) imaging methods have revealed the spatial and temporal assemblies of many macromolecules involved in different cellular processes in bacteria at a resolution of a few nanometers in their native milieu. Specifically, the application of cryo-focused ion beam (cryo-FIB) milling to thin bacterial specimens makes them amenable for high-resolution cryo-ET data collection. In this review, we highlight recent research in three emerging areas of bacterial cell biology that have benefited from the cryo-FIB-ET technology - cytoskeletal filament assembly, intracellular organelles, and multicellularity.
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9
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Carpousis AJ, Campo N, Hadjeras L, Hamouche L. Compartmentalization of RNA Degradosomes in Bacteria Controls Accessibility to Substrates and Ensures Concerted Degradation of mRNA to Nucleotides. Annu Rev Microbiol 2022; 76:533-552. [PMID: 35671533 DOI: 10.1146/annurev-micro-041020-113308] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
RNA degradosomes are multienzyme complexes composed of ribonucleases, RNA helicases, and metabolic enzymes. RNase E-based degradosomes are widespread in Proteobacteria. The Escherichia coli RNA degradosome is sequestered from transcription in the nucleoid and translation in the cytoplasm by localization to the inner cytoplasmic membrane, where it forms short-lived clusters that are proposed to be sites of mRNA degradation. In Caulobacter crescentus, RNA degradosomes localize to ribonucleoprotein condensates in the interior of the cell [bacterial ribonucleoprotein-bodies (BR-bodies)], which have been proposed to drive the concerted degradation of mRNA to nucleotides. The turnover of mRNA in growing cells is important for maintaining pools of nucleotides for transcription and DNA replication. Membrane attachment of the E. coli RNA degradosome is necessary to avoid wasteful degradation of intermediates in ribosome assembly. Sequestering RNA degradosomes to C. crescentus BR-bodies, which exclude structured RNA, could have a similar role in protecting intermediates in ribosome assembly from degradation. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Agamemnon J Carpousis
- LMGM, Université de Toulouse, CNRS, UPS, CBI, Toulouse, France; , , .,TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - Nathalie Campo
- LMGM, Université de Toulouse, CNRS, UPS, CBI, Toulouse, France; , ,
| | - Lydia Hadjeras
- LMGM, Université de Toulouse, CNRS, UPS, CBI, Toulouse, France; , , .,Current affiliation: IMIB, University of Würzburg, Würzburg, Germany;
| | - Lina Hamouche
- LMGM, Université de Toulouse, CNRS, UPS, CBI, Toulouse, France; , ,
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Live imaging of Yersinia translocon formation and immune recognition in host cells. PLoS Pathog 2022; 18:e1010251. [PMID: 35604950 PMCID: PMC9173619 DOI: 10.1371/journal.ppat.1010251] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 06/07/2022] [Accepted: 04/21/2022] [Indexed: 11/19/2022] Open
Abstract
Yersinia enterocolitica employs a type three secretion system (T3SS) to translocate immunosuppressive effector proteins into host cells. To this end, the T3SS assembles a translocon/pore complex composed of the translocator proteins YopB and YopD in host cell membranes serving as an entry port for the effectors. The translocon is formed in a Yersinia-containing pre-phagosomal compartment that is connected to the extracellular space. As the phagosome matures, the translocon and the membrane damage it causes are recognized by the cell-autonomous immune system. We infected cells in the presence of fluorophore-labeled ALFA-tag-binding nanobodies with a Y. enterocolitica strain expressing YopD labeled with an ALFA-tag. Thereby we could record the integration of YopD into translocons and its intracellular fate in living host cells. YopD was integrated into translocons around 2 min after uptake of the bacteria into a phosphatidylinositol-4,5-bisphosphate enriched pre-phagosomal compartment and remained there for 27 min on average. Damaging of the phagosomal membrane as visualized with recruitment of GFP-tagged galectin-3 occurred in the mean around 14 min after translocon formation. Shortly after recruitment of galectin-3, guanylate-binding protein 1 (GBP-1) was recruited to phagosomes, which was accompanied by a decrease in the signal intensity of translocons, suggesting their degradation or disassembly. In sum, we were able for the first time to film the spatiotemporal dynamics of Yersinia T3SS translocon formation and degradation and its sensing by components of the cell-autonomous immune system.
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11
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Oliveira Paiva AM, Friggen AH, Douwes R, Wittekoek B, Smits WK. Practical observations on the use of fluorescent reporter systems in Clostridioides difficile. Antonie van Leeuwenhoek 2022; 115:297-323. [PMID: 35039954 DOI: 10.1007/s10482-021-01691-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 11/19/2021] [Indexed: 12/18/2022]
Abstract
Fluorescence microscopy is a valuable tool to study a broad variety of bacterial cell components and dynamics thereof. For Clostridioides difficile, the fluorescent proteins CFPopt, mCherryOpt and phiLOV2.1, and the self-labelling tags SNAPCd and HaloTag, hereafter collectively referred as fluorescent systems, have been described to explore different cellular pathways. In this study, we sought to characterize previously used fluorescent systems in C. difficile cells. We performed single cell analyses using fluorescence microscopy of exponentially growing C. difficile cells harbouring different fluorescent systems, either expressing these separately in the cytosol or fused to the C-terminus of HupA, under defined conditions. We show that the intrinsic fluorescence of C. difficile cells increases during growth, independent of sigB or spo0A. However, when C. difficile cells are exposed to environmental oxygen autofluorescence is enhanced. Cytosolic overexpression of the different fluorescent systems alone, using the same expression signals, showed heterogeneous expression of the fluorescent systems. High levels of mCherryOpt were toxic for C. difficile cells limiting the applicability of this fluorophore as a transcriptional reporter. When fused to HupA, a C. difficile histone-like protein, the fluorescent systems behaved similarly and did not affect the HupA overproduction phenotype. The present study compares several commonly used fluorescent systems for application as transcriptional or translational reporters in microscopy and summarizes the limitations and key challenges for live-cell imaging of C. difficile. Due to independence of molecular oxygen and fluorescent signal, SNAPCd appears the most suitable candidate for live-cell imaging in C. difficile to date.
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Affiliation(s)
- Ana M Oliveira Paiva
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands.,Center for Microbial Cell Biology, Leiden, The Netherlands.,Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198, Gif-sur-Yvette, France
| | - Annemieke H Friggen
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands.,Center for Microbial Cell Biology, Leiden, The Netherlands
| | - Roxanne Douwes
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands
| | - Bert Wittekoek
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands
| | - Wiep Klaas Smits
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands. .,Center for Microbial Cell Biology, Leiden, The Netherlands.
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12
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Kratz J, Geisler C, Egner A. ISM-assisted tomographic STED microscopy. OPTICS EXPRESS 2022; 30:939-956. [PMID: 35209272 DOI: 10.1364/oe.445441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Stimulated emission depletion (STED) microscopy theoretically provides unlimited resolution. However, in practice the achievable resolution in biological samples is essentially limited by photobleaching. One method which overcomes this problem is tomographic STED (tomoSTED) microscopy. In tomoSTED microscopy, one-dimensional depletion patterns facing in different directions are successively applied in order to acquire a highly-resolved image in two dimensions. In this context, the number of addressed directions depends on the desired angular homogeneity of the point spread function or the optical transfer function and thus on the resolution increase as compared to diffraction-limited imaging. At a reasonable angular homogeneity the light dose and thus bleaching can be reduced, as compared to conventional STED microscopy. Here, we propose and demonstrate for the first time, to our knowledge, that the number of required depletion pattern orientations can be reduced by combining tomoSTED microscopy with the concept of image scanning microscopy (ISM). With our realization of an ISM-tomoSTED microscope, we show that approximately a factor of 2 lower number of orientations are required to achieve the same resolution and image quality as in tomoSTED microscopy.
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13
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Computerized fluorescence microscopy of microbial cells. World J Microbiol Biotechnol 2021; 37:189. [PMID: 34617135 DOI: 10.1007/s11274-021-03159-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/30/2021] [Indexed: 10/20/2022]
Abstract
The upgrading of fluorescence microscopy by the introduction of computer technologies has led to the creation of a new methodology, computerized fluorescence microscopy (CFM). CFM improves subjective visualization and combines it with objective quantitative analysis of the microscopic data. CFM has opened up two fundamentally new opportunities for studying microorganisms. The first is the quantitative measurement of the fluorescence parameters of the targeted fluorophores in association with certain structures of individual cells. The second is the expansion of the boundaries of visualization/resolution of intracellular components beyond the "diffraction limit" of light microscopy into the nanometer range. This enables to obtain unique information about the localization and dynamics of intracellular processes at the molecular level. The purpose of this review is to demonstrate the potential of CFM in the study of fundamental aspects of the structural and functional organization of microbial cells. The basics of computer processing and analysis of digital images are briefly described. The fluorescent molecules used in CFM with an emphasis on fluorescent proteins are characterized. The main methods of super-resolution microscopy (nanoscopy) are presented. The capabilities of various CFM methods for exploring microbial cells at the subcellular level are illustrated by the examples of various studies on yeast and bacteria.
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14
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Maria Ranieri A, Vezzelli M, Leslie KG, Huang S, Stagni S, Jacquemin D, Jiang H, Hubbard A, Rigamonti L, Watkin ELJ, Ogden MI, New EJ, Massi M. Structure illumination microscopy imaging of lipid vesicles in live bacteria with naphthalimide-appended organometallic complexes. Analyst 2021; 146:3818-3822. [PMID: 34036982 DOI: 10.1039/d1an00363a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
There is a lack of molecular probes for imaging bacteria, in comparison to the array of such tools available for the imaging of mammalian cells. Here, organometallic molecular probes have been developed and assessed for bacterial imaging, designed to have the potential to support multiple imaging modalities. The chemical structure of the probes is designed around a metal-naphthalimide structure. The 4-amino-1,8-naphthalimide moiety, covalently appended through a pyridine ancillary ligand, acts as a luminescent probe for super-resolution microscopy. On the other hand, the metal centre, rhenium(i) or platinum(ii) in the current study, enables techniques such as nanoSIMS. While the rhenium(i) complex was not sufficiently stable to be used as a probe, the platinum(ii) analogue showed good chemical and biological stability. Structured illumination microscopy (SIM) imaging on live Bacillus cereus confirmed the suitability of the probe for super-resolution microscopy. NanoSIMS analysis was used to monitor the uptake of the platinum(ii) complex within the bacteria and demonstrate the potential of this chemical architecture to enable multimodal imaging. The successful combination of these two moieties introduces a platform that could lead to a versatile range of multi-functional probes for bacteria.
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Affiliation(s)
- Anna Maria Ranieri
- School of Molecular and Life Sciences, Curtin University, Bentley 6102, WA, Australia.
| | - Matteo Vezzelli
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, via G. Campi 103, 41125 Modena, Italy
| | - Kathryn G Leslie
- School of Chemistry, The University of Sydney, 2006 NSW, Australia.
| | - Song Huang
- Centre for Microscopy, Characterisation and Analysis, Univsersity of Western Australia, 6009 Perth, WA, Australia
| | - Stefano Stagni
- Dipartimento di Chimica Industriale "Toso Montanari", Università degli Studi di Bologna, viale del Risorgimento 4, 40136 Bologna, Italy
| | - Denis Jacquemin
- Laboratoire CEISAM, UMR CNRS 6230, Universit8 de Nantes, 2 Rue de la HoussiniHre, BP 92208, 44322 Nantes Cedex 3, France
| | - Haibo Jiang
- Centre for Microscopy, Characterisation and Analysis, Univsersity of Western Australia, 6009 Perth, WA, Australia
| | - Alysia Hubbard
- Centre for Microscopy, Characterisation and Analysis, Univsersity of Western Australia, 6009 Perth, WA, Australia
| | - Luca Rigamonti
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, via G. Campi 103, 41125 Modena, Italy
| | - Elizabeth L J Watkin
- Curtin Medical School, Curtin University, Kent Street, Bentley 6102 WA, Australia
| | - Mark I Ogden
- School of Molecular and Life Sciences, Curtin University, Bentley 6102, WA, Australia.
| | - Elizabeth J New
- School of Chemistry, The University of Sydney, 2006 NSW, Australia.
| | - Massimiliano Massi
- School of Molecular and Life Sciences, Curtin University, Bentley 6102, WA, Australia.
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15
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Saraf M, Tavakkoli Yaraki M, Prateek, Tan YN, Gupta RK. Insights and Perspectives Regarding Nanostructured Fluorescent Materials toward Tackling COVID-19 and Future Pandemics. ACS APPLIED NANO MATERIALS 2021; 4:911-948. [PMID: 37556236 PMCID: PMC7885806 DOI: 10.1021/acsanm.0c02945] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/26/2021] [Indexed: 07/28/2023]
Abstract
The COVID-19 outbreak has exposed the world's preparation to fight against unknown/unexplored infectious and life-threatening pathogens. The unavailability of vaccines, slow or sometimes unreliable real-time virus/bacteria detection techniques, insufficient personal protective equipment (PPE), and a shortage of ventilators and many other transportation equipments have further raised serious concerns. Material research has been playing a pivotal role in developing antimicrobial agents for water treatment and photodynamic therapy, fast and ultrasensitive biosensors for virus/biomarkers detection, as well as for relevant biomedical and environmental applications. It has been noticed that these research efforts nowadays primarily focus on the nanomaterials-based platforms owing to their simplicity, reliability, and feasibility. In particular, nanostructured fluorescent materials have shown key potential due to their fascinating optical and unique properties at the nanoscale to combat against a COVID-19 kind of pandemic. Keeping these points in mind, this review attempts to give a perspective on the four key fluorescent materials of different families, including carbon dots, metal nanoclusters, aggregation-induced-emission luminogens, and MXenes, which possess great potential for the development of ultrasensitive biosensors and infective antimicrobial agents to fight against various infections/diseases. Particular emphasis has been given to the biomedical and environmental applications that are linked directly or indirectly to the efforts in combating COVID-19 pandemics. This review also aims to raise the awareness of researchers and scientists across the world to utilize such powerful materials in tackling similar pandemics in future.
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Affiliation(s)
- Mohit Saraf
- Department of Chemical Engineering,
Indian Institute of Technology Kanpur, Kanpur 208016, Uttar
Pradesh, India
| | - Mohammad Tavakkoli Yaraki
- Department of Chemical and Biomolecular Engineering,
National University of Singapore, 4 Engineering Drive 4,
117585, Singapore
- Research and Development Department,
Nanofy Technologies Pte. Ltd., 048580,
Singapore
| | - Prateek
- Department of Chemical Engineering,
Indian Institute of Technology Kanpur, Kanpur 208016, Uttar
Pradesh, India
| | - Yen Nee Tan
- Faculty of Science, Agriculture & Engineering,
Newcastle University, Newcastle upon Tyne NE1 7RU,
U.K.
- Newcastle Research & Innovation Institute,
Devan Nair Institute for Employment & Employability, 80
Jurong East Street 21, 609607, Singapore
| | - Raju Kumar Gupta
- Department of Chemical Engineering,
Indian Institute of Technology Kanpur, Kanpur 208016, Uttar
Pradesh, India
- Centre for Environmental Science and Engineering,
Indian Institute of Technology Kanpur, Kanpur 208016, Uttar
Pradesh, India
- Department of Sustanable Energy Engineering,
Indian Institute of Technology Kanpur, Kanpur 208016, Uttar
Pradesh, India
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16
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Abstract
Bacteria possess a sophisticated arsenal of defense mechanisms that allow them to survive in adverse conditions. Adaptation to acid stress and hypoxia is crucial for the enterobacterial transmission in the gastrointestinal tract of their human host. When subjected to low pH, Escherichia coli and many other enterobacteria activate a proton-consuming resistance system based on the acid stress-inducible lysine decarboxylase LdcI. Here we develop generally applicable tools to uncover the spatial localization of LdcI inside the cell by superresolution fluorescence microscopy and investigate the in vitro supramolecular organization of this enzyme by cryo-EM. We build on these results to propose a mechanistic model for LdcI function and offer tools for further in vivo investigations. Pathogenic and commensal bacteria often have to resist the harsh acidity of the host stomach. The inducible lysine decarboxylase LdcI buffers the cytosol and the local extracellular environment to ensure enterobacterial survival at low pH. Here, we investigate the acid stress-response regulation of Escherichia coli LdcI by combining biochemical and biophysical characterization with negative stain and cryoelectron microscopy (cryo-EM) and wide-field and superresolution fluorescence imaging. Due to deleterious effects of fluorescent protein fusions on native LdcI decamers, we opt for three-dimensional localization of nanobody-labeled endogenous wild-type LdcI in acid-stressed E. coli cells and show that it organizes into distinct patches at the cell periphery. Consistent with recent hypotheses that in vivo clustering of metabolic enzymes often reflects their polymerization as a means of stimulus-induced regulation, we show that LdcI assembles into filaments in vitro at physiologically relevant low pH. We solve the structures of these filaments and of the LdcI decamer formed at neutral pH by cryo-EM and reveal the molecular determinants of LdcI polymerization, confirmed by mutational analysis. Finally, we propose a model for LdcI function inside the enterobacterial cell, providing a structural and mechanistic basis for further investigation of the role of its supramolecular organization in the acid stress response.
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Peñate Medina T, Kolb JP, Hüttmann G, Huber R, Peñate Medina O, Ha L, Ulloa P, Larsen N, Ferrari A, Rafecas M, Ellrichmann M, Pravdivtseva MS, Anikeeva M, Humbert J, Both M, Hundt JE, Hövener JB. Imaging Inflammation - From Whole Body Imaging to Cellular Resolution. Front Immunol 2021; 12:692222. [PMID: 34248987 PMCID: PMC8264453 DOI: 10.3389/fimmu.2021.692222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/12/2021] [Indexed: 01/31/2023] Open
Abstract
Imaging techniques have evolved impressively lately, allowing whole new concepts like multimodal imaging, personal medicine, theranostic therapies, and molecular imaging to increase general awareness of possiblities of imaging to medicine field. Here, we have collected the selected (3D) imaging modalities and evaluated the recent findings on preclinical and clinical inflammation imaging. The focus has been on the feasibility of imaging to aid in inflammation precision medicine, and the key challenges and opportunities of the imaging modalities are presented. Some examples of the current usage in clinics/close to clinics have been brought out as an example. This review evaluates the future prospects of the imaging technologies for clinical applications in precision medicine from the pre-clinical development point of view.
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Affiliation(s)
- Tuula Peñate Medina
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center, Schleswig-Holstein Kiel University, Kiel, Germany
- *Correspondence: Tuula Peñate Medina, ; Jan-Bernd Hövener,
| | - Jan Philip Kolb
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
| | - Gereon Hüttmann
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
- Airway Research Center North (ARCN), Member of the German Center of Lung Research (DZL), Gießen, Germany
| | - Robert Huber
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
| | - Oula Peñate Medina
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center, Schleswig-Holstein Kiel University, Kiel, Germany
- Institute for Experimental Cancer Research (IET), University of Kiel, Kiel, Germany
| | - Linh Ha
- Department of Dermatology, Allergology and Venereology, University Hospital Schleswig-Holstein Lübeck (UKSH), Lübeck, Germany
| | - Patricia Ulloa
- Department of Radiology and Neuroradiology, University Medical Centers Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Naomi Larsen
- Department of Radiology and Neuroradiology, University Medical Centers Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Arianna Ferrari
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center, Schleswig-Holstein Kiel University, Kiel, Germany
| | - Magdalena Rafecas
- Institute of Medical Engineering (IMT), University of Lübeck, Lübeck, Germany
| | - Mark Ellrichmann
- Interdisciplinary Endoscopy, Medical Department1, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Mariya S. Pravdivtseva
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center, Schleswig-Holstein Kiel University, Kiel, Germany
- Department of Radiology and Neuroradiology, University Medical Centers Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Mariia Anikeeva
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center, Schleswig-Holstein Kiel University, Kiel, Germany
| | - Jana Humbert
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center, Schleswig-Holstein Kiel University, Kiel, Germany
- Department of Radiology and Neuroradiology, University Medical Centers Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Marcus Both
- Department of Radiology and Neuroradiology, University Medical Centers Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Jennifer E. Hundt
- Lübeck Institute for Experimental Dermatology (LIED), University of Lübeck, Lübeck, Germany
| | - Jan-Bernd Hövener
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center, Schleswig-Holstein Kiel University, Kiel, Germany
- *Correspondence: Tuula Peñate Medina, ; Jan-Bernd Hövener,
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18
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Cambré A, Aertsen A. Bacterial Vivisection: How Fluorescence-Based Imaging Techniques Shed a Light on the Inner Workings of Bacteria. Microbiol Mol Biol Rev 2020; 84:e00008-20. [PMID: 33115939 PMCID: PMC7599038 DOI: 10.1128/mmbr.00008-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The rise in fluorescence-based imaging techniques over the past 3 decades has improved the ability of researchers to scrutinize live cell biology at increased spatial and temporal resolution. In microbiology, these real-time vivisections structurally changed the view on the bacterial cell away from the "watery bag of enzymes" paradigm toward the perspective that these organisms are as complex as their eukaryotic counterparts. Capitalizing on the enormous potential of (time-lapse) fluorescence microscopy and the ever-extending pallet of corresponding probes, initial breakthroughs were made in unraveling the localization of proteins and monitoring real-time gene expression. However, later it became clear that the potential of this technique extends much further, paving the way for a focus-shift from observing single events within bacterial cells or populations to obtaining a more global picture at the intra- and intercellular level. In this review, we outline the current state of the art in fluorescence-based vivisection of bacteria and provide an overview of important case studies to exemplify how to use or combine different strategies to gain detailed information on the cell's physiology. The manuscript therefore consists of two separate (but interconnected) parts that can be read and consulted individually. The first part focuses on the fluorescent probe pallet and provides a perspective on modern methodologies for microscopy using these tools. The second section of the review takes the reader on a tour through the bacterial cell from cytoplasm to outer shell, describing strategies and methods to highlight architectural features and overall dynamics within cells.
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Affiliation(s)
- Alexander Cambré
- KU Leuven, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, Leuven, Belgium
| | - Abram Aertsen
- KU Leuven, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, Leuven, Belgium
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19
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Marshall AP, Shirley JD, Carlson EE. Enzyme-targeted fluorescent small-molecule probes for bacterial imaging. Curr Opin Chem Biol 2020; 57:155-165. [PMID: 32799037 DOI: 10.1016/j.cbpa.2020.05.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 12/26/2022]
Abstract
Molecular imaging methods to visualize myriad biochemical processes in bacteria have traditionally been dependent upon molecular biology techniques to incorporate fluorescent biomolecules (e.g., fusion proteins). Such methods have been instrumental in our understanding of how bacteria function but are not without drawbacks, including potential perturbation to native protein expression and function. To overcome these limitations, the use of fluorescent small-molecule probes has gained much attention. Here, we highlight examples from the recent literature that showcase the utility of small-molecule probes for the fluorescence imaging of bacterial cells, including electrophilic, metabolic, and enzyme-activated probes. Although the use of these types of compounds for bacterial imaging is still relatively new, the selected examples demonstrate the exciting potential of these critical tools in the exploration of bacterial physiology.
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Affiliation(s)
- Andrew P Marshall
- Department of Chemistry, University of Minnesota, Minneapolis, MN, United States
| | - Joshua D Shirley
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, United States
| | - Erin E Carlson
- Department of Chemistry, University of Minnesota, Minneapolis, MN, United States; Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, United States; Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States.
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20
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Celiksoy S, Ye W, Wandner K, Schlapp F, Kaefer K, Ahijado-Guzmán R, Sönnichsen C. Plasmonic Nanosensors for the Label-Free Imaging of Dynamic Protein Patterns. J Phys Chem Lett 2020; 11:4554-4558. [PMID: 32436712 DOI: 10.1021/acs.jpclett.0c01400] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We introduce a new approach to monitor the dynamics and spatial patterns of biological molecular assemblies. Our molecular imaging method relies on plasmonic gold nanoparticles as point-like detectors and requires no labeling of the molecules. We show spatial resolution of up to 5 μm and 30 ms temporal resolution, which is comparable to wide-field fluorescence microscopy, while requiring only readily available gold nanoparticles and a dark-field optical microscope. We demonstrate the method on MinDE proteins attaching to and detaching from lipid membranes of different composition for 24 h. We foresee our new imaging method as an indispensable tool in advanced molecular biology and biophysics laboratories around the world.
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Affiliation(s)
- Sirin Celiksoy
- Institute of Physical Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Weixiang Ye
- Institute of Physical Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Karl Wandner
- Institute of Physical Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Felix Schlapp
- Institute of Physical Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Katharina Kaefer
- Institute of Physical Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Rubén Ahijado-Guzmán
- Institute of Physical Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Carsten Sönnichsen
- Institute of Physical Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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21
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Abstract
All living organisms must degrade mRNA to adapt gene expression to changing environments. In bacteria, initiation of mRNA decay generally occurs through an endonucleolytic cleavage. In the Gram-positive model organism Bacillus subtilis and probably many other bacteria, the key enzyme for this task is RNase Y, which is anchored at the inner cell membrane. While this pseudocompartmentalization appears coherent with translation occurring primarily at the cell periphery, our knowledge on the distribution and dynamics of RNase Y in living cells is very scarce. Here, we show that RNase Y moves rapidly along the membrane in the form of dynamic short-lived foci. These foci become more abundant and increase in size following transcription arrest, suggesting that they do not constitute the most active form of the nuclease. This contrasts with RNase E, the major decay-initiating RNase in E. coli, where it was shown that formation of foci is dependent on the presence of RNA substrates. We also show that a protein complex (Y-complex) known to influence the specificity of RNase Y activity in vivo is capable of shifting the assembly status of RNase Y toward fewer and smaller complexes. This highlights fundamental differences between RNase E- and RNase Y-based degradation machineries. Metabolic turnover of mRNA is fundamental to the control of gene expression in all organisms, notably in fast-adapting prokaryotes. In many bacteria, RNase Y initiates global mRNA decay via an endonucleolytic cleavage, as shown in the Gram-positive model organism Bacillus subtilis. This enzyme is tethered to the inner cell membrane, a pseudocompartmentalization coherent with its task of initiating mRNA cleavage/maturation of mRNAs that are translated at the cell periphery. Here, we used total internal reflection fluorescence microscopy (TIRFm) and single-particle tracking (SPT) to visualize RNase Y and analyze its distribution and dynamics in living cells. We find that RNase Y diffuses rapidly at the membrane in the form of dynamic short-lived foci. Unlike RNase E, the major decay-initiating RNase in Escherichia coli, the formation of foci is not dependent on the presence of RNA substrates. On the contrary, RNase Y foci become more abundant and increase in size following transcription arrest, suggesting that they do not constitute the most active form of the nuclease. The Y-complex of three proteins (YaaT, YlbF, and YmcA) has previously been shown to play an important role for RNase Y activity in vivo. We demonstrate that Y-complex mutations have an effect similar to but much stronger than that of depletion of RNA in increasing the number and size of RNase Y foci at the membrane. Our data suggest that the Y-complex shifts the assembly status of RNase Y toward fewer and smaller complexes, thereby increasing cleavage efficiency of complex substrates like polycistronic mRNAs.
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22
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Abstract
Plasmids are ubiquitous in the microbial world and have been identified in almost all species of bacteria that have been examined. Their localization inside the bacterial cell has been examined for about two decades; typically, they are not randomly distributed, and their positioning depends on copy number and their mode of segregation. Low-copy-number plasmids promote their own stable inheritance in their bacterial hosts by encoding active partition systems, which ensure that copies are positioned in both halves of a dividing cell. High-copy plasmids rely on passive diffusion of some copies, but many remain clustered together in the nucleoid-free regions of the cell. Here we review plasmid localization and partition (Par) systems, with particular emphasis on plasmids from Enterobacteriaceae and on recent results describing the in vivo localization properties and molecular mechanisms of each system. Partition systems also cause plasmid incompatibility such that distinct plasmids (with different replicons) with the same Par system cannot be stably maintained in the same cells. We discuss how partition-mediated incompatibility is a consequence of the partition mechanism.
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23
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Petersen I, Schlüter R, Hoff KJ, Liebscher V, Bange G, Riedel K, Pané-Farré J. Non-invasive and label-free 3D-visualization shows in vivo oligomerization of the staphylococcal alkaline shock protein 23 (Asp23). Sci Rep 2020; 10:125. [PMID: 31924851 PMCID: PMC6954212 DOI: 10.1038/s41598-019-56907-9] [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: 10/02/2019] [Accepted: 12/04/2019] [Indexed: 11/26/2022] Open
Abstract
Fluorescence-tags, commonly used to visualize the spatial distribution of proteins within cells, can influence the localization of the tagged proteins by affecting their stability, interaction with other proteins or the induction of oligomerization artifacts. To circumvent these obstacles, a protocol was developed to generate 50 nm thick serial sections suitable for immunogold labeling and subsequent reconstruction of the spatial distribution of immuno-labeled native proteins within individual bacterial cells. Applying this method, we show a cellular distribution of the staphylococcal alkaline shock protein 23 (Asp23), which is compatible with filament formation, a property of Asp23 that we also demonstrate in vitro.
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Affiliation(s)
- Inga Petersen
- University of Greifswald, Institute of Microbiology, Felix-Hausdorff-Str. 8, 17489, Greifswald, Germany.,Center for Functional Genomics of Microbes, Felix-Hausdorff-Str. 8, 17489, Greifswald, Germany
| | - Rabea Schlüter
- University of Greifswald, Imaging Center of the Department of Biology, Friedrich-Ludwig-Jahn-Str. 15, 17489, Greifswald, Germany
| | - Katharina J Hoff
- University of Greifswald, Institute of Mathematics and Computer Science, Walther-Rathenau-Str. 47, 17489, Greifswald, Germany.,Center for Functional Genomics of Microbes, Felix-Hausdorff-Str. 8, 17489, Greifswald, Germany
| | - Volkmar Liebscher
- University of Greifswald, Institute of Mathematics and Computer Science, Walther-Rathenau-Str. 47, 17489, Greifswald, Germany
| | - Gert Bange
- Philipps-University Marburg, SYNMIKRO Research Center and Department of Chemistry, Hans-Meerwein-Strasse 6, C07, 35043, Marburg, Germany
| | - Katharina Riedel
- University of Greifswald, Institute of Microbiology, Felix-Hausdorff-Str. 8, 17489, Greifswald, Germany.,Center for Functional Genomics of Microbes, Felix-Hausdorff-Str. 8, 17489, Greifswald, Germany
| | - Jan Pané-Farré
- University of Greifswald, Institute of Microbiology, Felix-Hausdorff-Str. 8, 17489, Greifswald, Germany. .,Center for Functional Genomics of Microbes, Felix-Hausdorff-Str. 8, 17489, Greifswald, Germany. .,Philipps-University Marburg, SYNMIKRO Research Center and Department of Chemistry, Hans-Meerwein-Strasse 6, C07, 35043, Marburg, Germany.
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Abstract
MreB proteins are actin homologs present in nonspherical bacteria. They assemble into membrane-associated discrete filamentous structures that exhibit different dynamic behaviors along the bacterial sidewalls. Total internal reflection fluorescence (TIRF) microscopy, a sensitive method for studying molecular events at cell surfaces with high contrast and temporal resolution, is a method of choice to characterize the localization and dynamics of cortical MreB assemblies in vivo. This chapter describes the methods for visualizing fluorescently tagged MreB proteins in live Bacillus subtilis cells. We detail how to (1) grow B. subtilis strains for reproducible TIRF observations, (2) immobilize cells on agarose pads and (3) in CellASIC® microfluidic plates, and (4) acquire TIRF images and time lapses.
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25
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Brzozowski RS, White ML, Eswara PJ. Live-Cell Fluorescence Microscopy to Investigate Subcellular Protein Localization and Cell Morphology Changes in Bacteria. J Vis Exp 2019. [PMID: 31814606 DOI: 10.3791/59905] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Investigations of factors influencing cell division and cell shape in bacteria are commonly performed in conjunction with high-resolution fluorescence microscopy as observations made at a population level may not truly reflect what occurs at a single cell level. Live-cell timelapse microscopy allows investigators to monitor the changes in cell division or cell morphology which provide valuable insights regarding subcellular localization of proteins and timing of gene expression, as it happens, to potentially aid in answering important biological questions. Here, we describe our protocol to monitor phenotypic changes in Bacillus subtilis and Staphylococcus aureus using a high-resolution deconvolution microscope. The objective of this report is to provide a simple and clear protocol that can be adopted by other investigators interested in conducting fluorescence microscopy experiments to study different biological processes in bacteria as well as other organisms.
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Affiliation(s)
- Robert S Brzozowski
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida
| | - Maria L White
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida
| | - Prahathees J Eswara
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida;
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26
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Peng MW, Wei XY, Yu Q, Yan P, Chen YP, Guo JS. Identification of ceftazidime interaction with bacteria in wastewater treatment by Raman spectroscopic mapping. RSC Adv 2019; 9:32744-32752. [PMID: 35529746 PMCID: PMC9073089 DOI: 10.1039/c9ra06006e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 10/03/2019] [Indexed: 01/02/2023] Open
Abstract
Raman spectroscopy yields a fingerprint spectrum and is of great importance in medical and biological sciences as it is non-destructive, non-invasive, and available in the aqueous environment. In this study, Raman spectroscopy and Raman mapping were used to explore the dynamic biochemical processes in screened bacteria under ceftazidime stress. The Raman spectral difference between bacteria with and without antibiotic stress was analyzed by principal component analysis and characteristic peaks were obtained. The results showed that amino acids changed first and lipids were reduced when bacteria were exposed to ceftazidime stress. Furthermore, in Raman mapping, when bacteria were subjected to antibiotic stress, the peak at 1002 cm-1 (phenylalanine) increased, while the peak at 1172 cm-1 (lipids) weakened. This indicates that when bacteria were stimulated by antibiotics, the intracellular lipids decreased and the content of specific amino acids increased. The reduction of intracellular lipids may suggest a change of membrane permeability. The increase of specific amino acids suggests that bacteria resist external stimuli of antibiotics by regulating the activities of related enzymes. This study explored the processes of the action between bacteria and antibiotics by Raman spectroscopy, and provides a foundation for the further study of the dynamics of microbial biochemical processes in the future.
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Affiliation(s)
- Meng-Wen Peng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University Chongqing 400045 China +86-23-65935818 +86-23-65935818
| | - Xiang-Yang Wei
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University Chongqing 400045 China +86-23-65935818 +86-23-65935818
| | - Qiang Yu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University Chongqing 400045 China +86-23-65935818 +86-23-65935818
| | - Peng Yan
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University Chongqing 400045 China +86-23-65935818 +86-23-65935818
| | - You-Peng Chen
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University Chongqing 400045 China +86-23-65935818 +86-23-65935818
| | - Jin-Song Guo
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University Chongqing 400045 China +86-23-65935818 +86-23-65935818
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27
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Ranieri AM, Caporale C, Fiorini V, Hubbard A, Rigby P, Stagni S, Watkin E, Ogden MI, Hackett MJ, Massi M. Complementary Approaches to Imaging Subcellular Lipid Architectures in Live Bacteria Using Phosphorescent Iridium Complexes and Raman Spectroscopy. Chemistry 2019; 25:10566-10570. [DOI: 10.1002/chem.201902023] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/11/2019] [Indexed: 01/23/2023]
Affiliation(s)
- Anna Maria Ranieri
- Curtin Institute for Functional Molecules and Interfaces, and School of Molecular and Life SciencesCurtin University Bentley 6102 WA Australia
| | - Chiara Caporale
- Curtin Institute for Functional Molecules and Interfaces, and School of Molecular and Life SciencesCurtin University Bentley 6102 WA Australia
| | - Valentina Fiorini
- Department of Industrial Chemistry “Toso Montanari”University of Bologna, viale del Risorgimento4 40136 Bologna Italy
| | - Alysia Hubbard
- Centre for Microscopy, Characterisation and AnalysisThe University of Western Australia Perth 6009 WA Australia
| | - Paul Rigby
- Centre for Microscopy, Characterisation and AnalysisThe University of Western Australia Perth 6009 WA Australia
| | - Stefano Stagni
- Department of Industrial Chemistry “Toso Montanari”University of Bologna, viale del Risorgimento4 40136 Bologna Italy
| | - Elizabeth Watkin
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research InstituteCurtin University Kent Street Bentley 6102 Australia
| | - Mark I. Ogden
- Curtin Institute for Functional Molecules and Interfaces, and School of Molecular and Life SciencesCurtin University Bentley 6102 WA Australia
| | - Mark J. Hackett
- Curtin Institute for Functional Molecules and Interfaces, and School of Molecular and Life SciencesCurtin University Bentley 6102 WA Australia
| | - Massimiliano Massi
- Curtin Institute for Functional Molecules and Interfaces, and School of Molecular and Life SciencesCurtin University Bentley 6102 WA Australia
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28
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Smit JH, Li Y, Warszawik EM, Herrmann A, Cordes T. ColiCoords: A Python package for the analysis of bacterial fluorescence microscopy data. PLoS One 2019; 14:e0217524. [PMID: 31216308 PMCID: PMC6583990 DOI: 10.1371/journal.pone.0217524] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 05/08/2019] [Indexed: 11/18/2022] Open
Abstract
Single-molecule fluorescence microscopy studies of bacteria provide unique insights into the mechanisms of cellular processes and protein machineries in ways that are unrivalled by any other technique. With the cost of microscopes dropping and the availability of fully automated microscopes, the volume of microscopy data produced has increased tremendously. These developments have moved the bottleneck of throughput from image acquisition and sample preparation to data analysis. Furthermore, requirements for analysis procedures have become more stringent given the demand of various journals to make data and analysis procedures available. To address these issues we have developed a new data analysis package for analysis of fluorescence microscopy data from rod-like cells. Our software ColiCoords structures microscopy data at the single-cell level and implements a coordinate system describing each cell. This allows for the transformation of Cartesian coordinates from transmission light and fluorescence images and single-molecule localization microscopy (SMLM) data to cellular coordinates. Using this transformation, many cells can be combined to increase the statistical power of fluorescence microscopy datasets of any kind. ColiCoords is open source, implemented in the programming language Python, and is extensively documented. This allows for modifications for specific needs or to inspect and publish data analysis procedures. By providing a format that allows for easy sharing of code and associated data, we intend to promote open and reproducible research. The source code and documentation can be found via the project's GitHub page.
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Affiliation(s)
- Jochem H. Smit
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Yichen Li
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Eliza M. Warszawik
- Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Andreas Herrmann
- Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
- DWI – Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany
| | - Thorben Cordes
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany
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29
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Altinoglu I, Merrifield CJ, Yamaichi Y. Single molecule super-resolution imaging of bacterial cell pole proteins with high-throughput quantitative analysis pipeline. Sci Rep 2019; 9:6680. [PMID: 31040310 PMCID: PMC6491441 DOI: 10.1038/s41598-019-43051-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 04/05/2019] [Indexed: 12/17/2022] Open
Abstract
Bacteria show sophisticated control of their cellular organization, and many bacteria deploy different polar landmark proteins to organize the cell pole. Super-resolution microscopy, such as Photo-Activated Localization Microscopy (PALM), provides the nanoscale localization of molecules and is crucial for better understanding of organization and dynamics in single-molecule. However, analytical tools are not fully available yet, in particular for bacterial cell biology. For example, quantitative and statistical analyses of subcellular localization with multiple cells from multiple fields of view are lacking. Furthermore, brightfield images are not sufficient to get accurate contours of small and low contrast bacterial cells, compared to subpixel presentation of target molecules. Here we describe a novel analytic tool for PALM which integrates precisely drawn cell outlines, of either inner membrane or periplasm, labelled by PALM-compatible fluorescent protein fusions, with molecule data for >10,000 molecules from >100 cells by fitting each cell into an oval arc. In the vibrioid bacterium Vibrio cholerae, the polar anchor HubP constitutes a big polar complex which includes multiple proteins involved in chemotaxis and the flagellum. With this pipeline, HubP is shown to be slightly skewed towards the inner curvature side of the cell, while its interaction partners showed rather loose polar localization.
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Affiliation(s)
- Ipek Altinoglu
- Department of Genome Biology, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Univ. Paris Sud, Gif sur Yvette, France.,Graduate School of Structure and Dynamics of Living Systems, Univ. Paris-Sud, Orsay, France
| | - Christien J Merrifield
- Department of Cell Biology, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Univ. Paris Sud, Gif sur Yvette, France
| | - Yoshiharu Yamaichi
- Department of Genome Biology, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Univ. Paris Sud, Gif sur Yvette, France.
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30
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Puchkov EO. Quantitative Methods for Single-Cell Analysis of Microorganisms. Microbiology (Reading) 2019. [DOI: 10.1134/s0026261719010120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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van Beljouw SPB, van der Els S, Martens KJA, Kleerebezem M, Bron PA, Hohlbein J. Evaluating single-particle tracking by photo-activation localization microscopy (sptPALM) in Lactococcus lactis. Phys Biol 2019; 16:035001. [PMID: 30673632 DOI: 10.1088/1478-3975/ab0162] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Lactic acid bacteria (LAB) are frequently used in food fermentation and are invaluable for the taste and nutritional value of the fermentation end-product. To gain a better understanding of underlying biochemical and microbiological mechanisms and cell-to-cell variability in LABs, single-molecule techniques such as single-particle tracking photo-activation localization microscopy (sptPALM) hold great promises but are not yet employed due to the lack of detailed protocols and suitable assays. Here, we qualitatively test various fluorescent proteins including variants that are photoactivatable and therefore suitable for sptPALM measurements in Lactococcus lactis, a key LAB for the dairy industry. In particular, we fused PAmCherry2 to dCas9 allowing the successful tracking of single dCas9 proteins, whilst the dCas9 chimeras bound to specific guide RNAs retained their gene silencing ability in vivo. The diffusional information of the dCas9 without any targets showed different mechanistic states of dCas9: freely diffusing, bound to DNA, or transiently interacting with DNA. The capability of performing sptPALM with dCas9 in L. lactis can lead to a better, general understanding of CRISPR-Cas systems as well as paving the way for CRISPR-Cas based interrogations of cellular functions in LABs.
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Affiliation(s)
- Sam P B van Beljouw
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands. These authors contributed equally
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32
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Ho SH, Tirrell DA. N-Myristoyl Transferase (NMT)-Catalyzed Labeling of Bacterial Proteins for Imaging in Fixed and Live Cells. Methods Mol Biol 2019; 2012:315-326. [PMID: 31161515 DOI: 10.1007/978-1-4939-9546-2_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Methods for selective protein imaging are critical for elucidating how cells orchestrate fundamental biological processes. We recently developed a chemoenzymatic method to modify bacterial proteins in situ for fluorescence imaging using N-myristoyl transferase (NMT). Target proteins outfitted with an N-terminal NMT recognition sequence are covalently modified with an azido fatty acid. Subsequent strain-promoted azide-alkyne cycloaddition allows for conjugation to cell-permeant fluorophores and imaging by fluorescence microscopy. Here we describe sample preparation and labeling protocols for imaging bacterial proteins in fixed and live cells.
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Affiliation(s)
- Samuel H Ho
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - David A Tirrell
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA.
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33
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Takacs CN, Kloos ZA, Scott M, Rosa PA, Jacobs-Wagner C. Fluorescent Proteins, Promoters, and Selectable Markers for Applications in the Lyme Disease Spirochete Borrelia burgdorferi. Appl Environ Microbiol 2018; 84:e01824-18. [PMID: 30315081 PMCID: PMC6275353 DOI: 10.1128/aem.01824-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/08/2018] [Indexed: 11/30/2022] Open
Abstract
Lyme disease is the most widely reported vector-borne disease in the United States. Its incidence is rapidly increasing, and disease symptoms can be debilitating. The need to understand the biology of the disease agent, the spirochete Borrelia burgdorferi, is thus evermore pressing. Despite important advances in B. burgdorferi genetics, the array of molecular tools available for use in this organism remains limited, especially for cell biological studies. Here, we adapt a palette of bright and mostly monomeric fluorescent proteins for versatile use and multicolor imaging in B. burgdorferi We also characterize two novel antibiotic selection markers and establish the feasibility of their use in conjunction with extant markers. Last, we describe a set of promoters of low and intermediate strengths that allow fine-tuning of gene expression levels. These molecular tools complement and expand current experimental capabilities in B. burgdorferi, which will facilitate future investigation of this important human pathogen. To showcase the usefulness of these reagents, we used them to investigate the subcellular localization of BB0323, a B. burgdorferi lipoprotein essential for survival in the host and vector environments. We show that BB0323 accumulates at the cell poles and future division sites of B. burgdorferi cells, highlighting the complex subcellular organization of this spirochete.IMPORTANCE Genetic manipulation of the Lyme disease spirochete B. burgdorferi remains cumbersome, despite significant progress in the field. The scarcity of molecular reagents available for use in this pathogen has slowed research efforts to study its unusual biology. Of interest, B. burgdorferi displays complex cellular organization features that have yet to be understood. These include an unusual morphology and a highly fragmented genome, both of which are likely to play important roles in the bacterium's transmission, infectivity, and persistence. Here, we complement and expand the array of molecular tools available for use in B. burgdorferi by generating and characterizing multiple fluorescent proteins, antibiotic selection markers, and promoters of varied strengths. These tools will facilitate investigations in this important human pathogen, as exemplified by the polar and midcell localization of the cell envelope regulator BB0323, which we uncovered using these reagents.
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Affiliation(s)
- Constantin N Takacs
- Microbial Sciences Institute, Yale West Campus, West Haven, Connecticut, USA
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale West Campus, West Haven, Connecticut, USA
| | - Zachary A Kloos
- Microbial Sciences Institute, Yale West Campus, West Haven, Connecticut, USA
- Microbiology Program, Yale University, New Haven, Connecticut, USA
| | - Molly Scott
- Microbial Sciences Institute, Yale West Campus, West Haven, Connecticut, USA
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale West Campus, West Haven, Connecticut, USA
| | - Patricia A Rosa
- Laboratory of Bacteriology, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Christine Jacobs-Wagner
- Microbial Sciences Institute, Yale West Campus, West Haven, Connecticut, USA
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale West Campus, West Haven, Connecticut, USA
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
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34
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Duan Y, Liu B. Recent Advances of Optical Imaging in the Second Near-Infrared Window. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1802394. [PMID: 30182451 DOI: 10.1002/adma.201802394] [Citation(s) in RCA: 376] [Impact Index Per Article: 62.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 05/19/2018] [Indexed: 05/20/2023]
Abstract
The near-infrared window between 1000 and 1700 nm, commonly termed the "second near-infrared (NIR-II) window," has quickly emerged as a highly attractive optical region for biological imaging. In contrast to conventional imaging in the visible region between 400 and 700 nm, as well as in the first NIR (NIR-I) window between 700 and 900 nm, NIR-II biological imaging offers numerous merits, including higher spatial resolution, deeper penetration depth, and lower optical absorption and scattering from biological substrates with minimal tissue autofluorescence. Noninvasive imaging techniques, specifically NIR-II fluorescence and photoacoustic (PA) imaging, have embodied the attractiveness of NIR-II optical imaging, with several NIR-II contrast agents demonstrating superior performance to the clinically approved NIR-I agents. Consequently, NIR-II biological imaging has been increasingly explored due to its tremendous potential for preclinical studies and clinical utility. Herein, the progress of optical imaging in the NIR-II window is reported. Starting with highlighting the importance of biological imaging in the NIR-II spectral region, the emergence and latest development of various NIR-II fluorescence and PA imaging probes and their applications are then discussed. Perspectives on the promises and challenges facing this nascent yet exciting field are then given.
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Affiliation(s)
- Yukun Duan
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 4 Engineering Drive 4, Singapore, 117585, Singapore
| | - Bin Liu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 4 Engineering Drive 4, Singapore, 117585, Singapore
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35
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Stauffer W, Sheng H, Lim HN. EzColocalization: An ImageJ plugin for visualizing and measuring colocalization in cells and organisms. Sci Rep 2018; 8:15764. [PMID: 30361629 PMCID: PMC6202351 DOI: 10.1038/s41598-018-33592-8] [Citation(s) in RCA: 173] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 10/01/2018] [Indexed: 02/07/2023] Open
Abstract
Insight into the function and regulation of biological molecules can often be obtained by determining which cell structures and other molecules they localize with (i.e. colocalization). Here we describe an open source plugin for ImageJ called EzColocalization to visualize and measure colocalization in microscopy images. EzColocalization is designed to be easy to use and customize for researchers with minimal experience in quantitative microscopy and computer programming. Features of EzColocalization include: (i) tools to select individual cells and organisms from images; (ii) filters to select specific types of cells and organisms based on physical parameters and signal intensity; (iii) heat maps and scatterplots to visualize the localization patterns of reporters; (iv) multiple metrics to measure colocalization for two or three reporters; (v) metric matrices to systematically measure colocalization at multiple combinations of signal intensity thresholds; and (vi) data tables that provide detailed information on each cell in a sample. These features make EzColocalization well-suited for experiments with low reporter signal, complex patterns of localization, and heterogeneous populations of cells and organisms.
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Affiliation(s)
- Weston Stauffer
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA
| | - Huanjie Sheng
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA
| | - Han N Lim
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA.
- Atomwise Inc., San Francisco, CA, USA.
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36
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Kenry, Liu B. Recent Advances in Biodegradable Conducting Polymers and Their Biomedical Applications. Biomacromolecules 2018; 19:1783-1803. [DOI: 10.1021/acs.biomac.8b00275] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Kenry
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 Singapore
| | - Bin Liu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 Singapore
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37
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Kok J, van Gijtenbeek LA, de Jong A, van der Meulen SB, Solopova A, Kuipers OP. The Evolution of gene regulation research in Lactococcus lactis. FEMS Microbiol Rev 2018; 41:S220-S243. [PMID: 28830093 DOI: 10.1093/femsre/fux028] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 06/15/2017] [Indexed: 11/12/2022] Open
Abstract
Lactococcus lactis is a major microbe. This lactic acid bacterium (LAB) is used worldwide in the production of safe, healthy, tasteful and nutritious milk fermentation products. Its huge industrial importance has led to an explosion of research on the organism, particularly since the early 1970s. The upsurge in the research on L. lactis coincided not accidentally with the advent of recombinant DNA technology in these years. The development of methods to take out and re-introduce DNA in L. lactis, to clone genes and to mutate the chromosome in a targeted way, to control (over)expression of proteins and, ultimately, the availability of the nucleotide sequence of its genome and the use of that information in transcriptomics and proteomics research have enabled to peek deep into the functioning of the organism. Among many other things, this has provided an unprecedented view of the major gene regulatory pathways involved in nitrogen and carbon metabolism and their overlap, and has led to the blossoming of the field of L. lactis systems biology. All of these advances have made L. lactis the paradigm of the LAB. This review will deal with the exciting path along which the research on the genetics of and gene regulation in L. lactis has trodden.
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Affiliation(s)
- Jan Kok
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands
| | - Lieke A van Gijtenbeek
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands
| | - Anne de Jong
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands
| | - Sjoerd B van der Meulen
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands
| | - Ana Solopova
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands
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38
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Abstract
Peptidoglycan is an essential component of the cell wall that protects bacteria from environmental stress. A carefully coordinated biosynthesis of peptidoglycan during cell elongation and division is required for cell viability. This biosynthesis involves sophisticated enzyme machineries that dynamically synthesize, remodel, and degrade peptidoglycan. However, when and where bacteria build peptidoglycan, and how this is coordinated with cell growth, have been long-standing questions in the field. The improvement of microscopy techniques has provided powerful approaches to study peptidoglycan biosynthesis with high spatiotemporal resolution. Recent development of molecular probes further accelerated the growth of the field, which has advanced our knowledge of peptidoglycan biosynthesis dynamics and mechanisms. Here, we review the technologies for imaging the bacterial cell wall and its biosynthesis activity. We focus on the applications of fluorescent d-amino acids, a newly developed type of probe, to visualize and study peptidoglycan synthesis and dynamics, and we provide direction for prospective research.
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Affiliation(s)
- Atanas D Radkov
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.,Current affiliation: Biophysics and Biochemistry Department, University of California, San Francisco, California 94158, USA;
| | - Yen-Pang Hsu
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA; , ,
| | - Garrett Booher
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA; , ,
| | - Michael S VanNieuwenhze
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.,Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA; , ,
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39
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Eguchi Y, Fukumori Y, Taoka A. Measuring magnetosomal pH of the magnetotactic bacterium Magnetospirillum magneticum AMB-1 using pH-sensitive fluorescent proteins. Biosci Biotechnol Biochem 2018; 82:1243-1251. [PMID: 29557302 DOI: 10.1080/09168451.2018.1451739] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Magnetotactic bacteria synthesize uniform-sized and regularly shaped magnetic nanoparticles in their organelles termed magnetosomes. Homeostasis of the magnetosome lumen must be maintained for its role accomplishment. Here, we developed a method to estimate the pH of a single living cell of the magnetotactic bacterium Magnetospirillum magneticum AMB-1 using a pH-sensitive fluorescent protein E2GFP. Using the pH measurement, we estimated that the cytoplasmic pH was approximately 7.6 and periplasmic pH was approximately 7.2. Moreover, we estimated pH in the magnetosome lumen and cytoplasmic surface using fusion proteins of E2GFP and magnetosome-associated proteins. The pH in the magnetosome lumen increased during the exponential growth phase when magnetotactic bacteria actively synthesize magnetite crystals, whereas pH at the magnetosome surface was not affected by the growth stage. This live-cell pH measurement method will help for understanding magnetosome pH homeostasis to reveal molecular mechanisms of magnetite biomineralization in the bacterial organelle.
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Affiliation(s)
- Yukako Eguchi
- a Department of Life Science, Graduate School of Natural Science and Technology , Kanazawa University , Kanazawa , Japan
| | - Yoshihiro Fukumori
- b Faculty of Natural System, Institute of Science and Engineering , Kanazawa University , Kanazawa , Japan
| | - Azuma Taoka
- b Faculty of Natural System, Institute of Science and Engineering , Kanazawa University , Kanazawa , Japan.,c Bio-AFM Frontier Research Center, College of Science and Engineering , Kanazawa University , Kanazawa , Japan
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40
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Abstract
Immunofluorescence microscopy is an invaluable tool for the study of biological processes at the cellular level. While the localization of surface-exposed antigens can easily be determined using fluorescent antibodies, localization of intracellular antigens requires permeabilization of the bacterial cell wall and membrane. Here, we describe an immunofluorescence protocol tailored specifically for Streptococcus pyogenes, applying the phage lysin PlyC for cell wall permeabilization. This protocol allows a high level of morphological preservation, suitable for high-resolution microscopy. With slight modification, this protocol could also be used for other Gram-positive pathogens.
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41
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Schneider JP, Basler M. Shedding light on biology of bacterial cells. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0499. [PMID: 27672150 PMCID: PMC5052743 DOI: 10.1098/rstb.2015.0499] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2016] [Indexed: 12/11/2022] Open
Abstract
To understand basic principles of living organisms one has to know many different properties of all cellular components, their mutual interactions but also their amounts and spatial organization. Live-cell imaging is one possible approach to obtain such data. To get multiple snapshots of a cellular process, the imaging approach has to be gentle enough to not disrupt basic functions of the cell but also have high temporal and spatial resolution to detect and describe the changes. Light microscopy has become a method of choice and since its early development over 300 years ago revolutionized our understanding of living organisms. As most cellular components are indistinguishable from the rest of the cellular contents, the second revolution came from a discovery of specific labelling techniques, such as fusions to fluorescent proteins that allowed specific tracking of a component of interest. Currently, several different tags can be tracked independently and this allows us to simultaneously monitor the dynamics of several cellular components and from the correlation of their dynamics to infer their respective functions. It is, therefore, not surprising that live-cell fluorescence microscopy significantly advanced our understanding of basic cellular processes. Current cameras are fast enough to detect changes with millisecond time resolution and are sensitive enough to detect even a few photons per pixel. Together with constant improvement of properties of fluorescent tags, it is now possible to track single molecules in living cells over an extended period of time with a great temporal resolution. The parallel development of new illumination and detection techniques allowed breaking the diffraction barrier and thus further pushed the resolution limit of light microscopy. In this review, we would like to cover recent advances in live-cell imaging technology relevant to bacterial cells and provide a few examples of research that has been possible due to imaging. This article is part of the themed issue ‘The new bacteriology’.
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Affiliation(s)
- Johannes P Schneider
- Focal Area Infection Biology, Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Marek Basler
- Focal Area Infection Biology, Biozentrum, University of Basel, 4056 Basel, Switzerland
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Tethered Magnets Are the Key to Magnetotaxis: Direct Observations of Magnetospirillum magneticum AMB-1 Show that MamK Distributes Magnetosome Organelles Equally to Daughter Cells. mBio 2017; 8:mBio.00679-17. [PMID: 28790202 PMCID: PMC5550748 DOI: 10.1128/mbio.00679-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Magnetotactic bacteria are a unique group of bacteria that synthesize a magnetic organelle termed the magnetosome, which they use to assist with their magnetic navigation in a specific type of bacterial motility called magneto-aerotaxis. Cytoskeletal filaments consisting of the actin-like protein MamK are associated with the magnetosome chain. Previously, the function of MamK was thought to be in positioning magnetosome organelles; this was proposed based on observations via electron microscopy still images. Here, we conducted live-cell time-lapse fluorescence imaging analyses employing highly inclined and laminated optical sheet microscopy, and these methods enabled us to visualize detailed dynamic movement of magnetosomes in growing cells during the entire cell cycle with high-temporal resolution and a high signal/noise ratio. We found that the MamK cytoskeleton anchors magnetosomes through a mechanism that requires MamK-ATPase activity throughout the cell cycle to prevent simple diffusion of magnetosomes within the cell. We concluded that the static chain-like arrangement of the magnetosomes is required to precisely and consistently segregate the magnetosomes to daughter cells. Thus, the daughter cells inherit a functional magnetic sensor that mediates magneto-reception. Half a century ago, bacterial cells were considered a simple “bag of enzymes”; only recently have they been shown to comprise ordered complexes of macromolecular structures, such as bacterial organelles and cytoskeletons, similar to their eukaryotic counterparts. In eukaryotic cells, the positioning of organelles is regulated by cytoskeletal elements. However, the role of cytoskeletal elements in the positioning of bacterial organelles, such as magnetosomes, remains unclear. Magnetosomes are associated with cytoskeletal filaments that consist of the actin-like protein MamK. In this study, we focused on how the MamK cytoskeleton regulates the dynamic movement of magnetosome organelles in living magnetotactic bacterial cells. Here, we used fluorescence imaging to visualize the dynamics of magnetosomes throughout the cell cycle in living magnetotactic bacterial cells to understand how they use the actin-like cytoskeleton to maintain and to make functional their nano-sized magnetic organelles.
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Goudsmits JMH, van Oijen AM, Robinson A. A Tool for Alignment and Averaging of Sparse Fluorescence Signals in Rod-Shaped Bacteria. Biophys J 2017; 110:1708-1715. [PMID: 27119631 DOI: 10.1016/j.bpj.2016.02.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 02/08/2016] [Accepted: 02/16/2016] [Indexed: 11/15/2022] Open
Abstract
Fluorescence microscopy studies have shown that many proteins localize to highly specific subregions within bacterial cells. Analyzing the spatial distribution of low-abundance proteins within cells is highly challenging because information obtained from multiple cells needs to be combined to provide well-defined maps of protein locations. We present (to our knowledge) a novel tool for fast, automated, and user-impartial analysis of fluorescent protein distribution across the short axis of rod-shaped bacteria. To demonstrate the strength of our approach in extracting spatial distributions and visualizing dynamic intracellular processes, we analyzed sparse fluorescence signals from single-molecule time-lapse images of individual Escherichia coli cells. In principle, our tool can be used to provide information on the distribution of signal intensity across the short axis of any rod-shaped object.
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Affiliation(s)
- Joris M H Goudsmits
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands
| | - Antoine M van Oijen
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands; School of Chemistry, University of Wollongong, Wollongong, New South Wales, Australia
| | - Andrew Robinson
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands; School of Chemistry, University of Wollongong, Wollongong, New South Wales, Australia.
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Billaudeau C, Chastanet A, Yao Z, Cornilleau C, Mirouze N, Fromion V, Carballido-López R. Contrasting mechanisms of growth in two model rod-shaped bacteria. Nat Commun 2017; 8:15370. [PMID: 28589952 PMCID: PMC5467245 DOI: 10.1038/ncomms15370] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 03/23/2017] [Indexed: 12/24/2022] Open
Abstract
How cells control their shape and size is a long-standing question in cell biology. Many rod-shaped bacteria elongate their sidewalls by the action of cell wall synthesizing machineries that are associated to actin-like MreB cortical patches. However, little is known about how elongation is regulated to enable varied growth rates and sizes. Here we use total internal reflection fluorescence microscopy and single-particle tracking to visualize MreB isoforms, as a proxy for cell wall synthesis, in Bacillus subtilis and Escherichia coli cells growing in different media and during nutrient upshift. We find that these two model organisms appear to use orthogonal strategies to adapt to growth regime variations: B. subtilis regulates MreB patch speed, while E. coli may mainly regulate the production capacity of MreB-associated cell wall machineries. We present numerical models that link MreB-mediated sidewall synthesis and cell elongation, and argue that the distinct regulatory mechanism employed might reflect the different cell wall integrity constraints in Gram-positive and Gram-negative bacteria. Protein MreB participates in elongation of sidewalls during growth of most rod-shaped bacteria. Here, the authors use fluorescence microscopy and single-particle tracking to visualize MreB, showing that Bacillus subtilis and Escherichia coli appear to use different strategies to adapt to growth rate variations.
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Affiliation(s)
- Cyrille Billaudeau
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Arnaud Chastanet
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Zhizhong Yao
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Charlène Cornilleau
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Nicolas Mirouze
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Vincent Fromion
- MaIAGE, INRA, Université Paris-Saclay, Jouy-en-Josas F78350, France
| | - Rut Carballido-López
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
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Visualization and characterization of individual type III protein secretion machines in live bacteria. Proc Natl Acad Sci U S A 2017; 114:6098-6103. [PMID: 28533372 PMCID: PMC5468683 DOI: 10.1073/pnas.1705823114] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Type III protein secretion machines have evolved to deliver bacterially encoded effector proteins into eukaryotic cells. Although electron microscopy has provided a detailed view of these machines in isolation or fixed samples, little is known about their organization in live bacteria. Here we report the visualization and characterization of the Salmonella type III secretion machine in live bacteria by 2D and 3D single-molecule switching superresolution microscopy. This approach provided access to transient components of this machine, which previously could not be analyzed. We determined the subcellular distribution of individual machines, the stoichiometry of the different components of this machine in situ, and the spatial distribution of the substrates of this machine before secretion. Furthermore, by visualizing this machine in Salmonella mutants we obtained major insights into the machine's assembly. This study bridges a major resolution gap in the visualization of this nanomachine and may serve as a paradigm for the examination of other bacterially encoded molecular machines.
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Goñi-Moreno Á, Kim J, de Lorenzo V. CellShape: A user-friendly image analysis tool for quantitative visualization of bacterial cell factories inside. Biotechnol J 2016; 12. [DOI: 10.1002/biot.201600323] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/24/2016] [Accepted: 07/25/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Ángel Goñi-Moreno
- Systems Biology Program, Centro Nacional de Biotecnología CSIC; Madrid Spain
| | - Juhyun Kim
- Systems Biology Program, Centro Nacional de Biotecnología CSIC; Madrid Spain
| | - Víctor de Lorenzo
- Systems Biology Program, Centro Nacional de Biotecnología CSIC; Madrid Spain
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Barlag B, Beutel O, Janning D, Czarniak F, Richter CP, Kommnick C, Göser V, Kurre R, Fabiani F, Erhardt M, Piehler J, Hensel M. Single molecule super-resolution imaging of proteins in living Salmonella enterica using self-labelling enzymes. Sci Rep 2016; 6:31601. [PMID: 27534893 PMCID: PMC4989173 DOI: 10.1038/srep31601] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 07/20/2016] [Indexed: 12/23/2022] Open
Abstract
The investigation of the subcellular localization, dynamics and interaction of proteins and protein complexes in prokaryotes is complicated by the small size of the cells. Super-resolution microscopy (SRM) comprise various new techniques that allow light microscopy with a resolution that can be up to ten-fold higher than conventional light microscopy. Application of SRM techniques to living prokaryotes demands the introduction of suitable fluorescent probes, usually by fusion of proteins of interest to fluorescent proteins with properties compatible to SRM. Here we describe an approach that is based on the genetically encoded self-labelling enzymes HaloTag and SNAP-tag. Proteins of interest are fused to HaloTag or SNAP-tag and cell permeable substrates can be labelled with various SRM-compatible fluorochromes. Fusions of the enzyme tags to subunits of a type I secretion system (T1SS), a T3SS, the flagellar rotor and a transcription factor were generated and analysed in living Salmonella enterica. The new approach is versatile in tagging proteins of interest in bacterial cells and allows to determine the number, relative subcellular localization and dynamics of protein complexes in living cells.
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Affiliation(s)
- Britta Barlag
- Abt. Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Oliver Beutel
- Abt. Biophysik, Universität Osnabrück, Osnabrück, Germany
| | - Dennis Janning
- Abt. Neurobiologie, Universität Osnabrück, Osnabrück, Germany
| | | | | | - Carina Kommnick
- Abt. Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Vera Göser
- Abt. Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Rainer Kurre
- CALMOS, Universität Osnabrück, Osnabrück, Germany
| | - Florian Fabiani
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Marc Erhardt
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Jacob Piehler
- Abt. Biophysik, Universität Osnabrück, Osnabrück, Germany
| | - Michael Hensel
- Abt. Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
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Spatial Organization of Cell Wall-Anchored Proteins at the Surface of Gram-Positive Bacteria. Curr Top Microbiol Immunol 2016; 404:177-201. [DOI: 10.1007/82_2016_4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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49
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Bridier A, Hammes F, Canette A, Bouchez T, Briandet R. Fluorescence-based tools for single-cell approaches in food microbiology. Int J Food Microbiol 2015; 213:2-16. [PMID: 26163933 DOI: 10.1016/j.ijfoodmicro.2015.07.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 06/26/2015] [Accepted: 07/03/2015] [Indexed: 12/31/2022]
Abstract
The better understanding of the functioning of microbial communities is a challenging and crucial issue in the field of food microbiology, as it constitutes a prerequisite to the optimization of positive and technological microbial population functioning, as well as for the better control of pathogen contamination of food. Heterogeneity appears now as an intrinsic and multi-origin feature of microbial populations and is a major determinant of their beneficial or detrimental functional properties. The understanding of the molecular and cellular mechanisms behind the behavior of bacteria in microbial communities requires therefore observations at the single-cell level in order to overcome "averaging" effects inherent to traditional global approaches. Recent advances in the development of fluorescence-based approaches dedicated to single-cell analysis provide the opportunity to study microbial communities with an unprecedented level of resolution and to obtain detailed insights on the cell structure, metabolism activity, multicellular behavior and bacterial interactions in complex communities. These methods are now increasingly applied in the field of food microbiology in different areas ranging from research laboratories to industry. In this perspective, we reviewed the main fluorescence-based tools used for single-cell approaches and their concrete applications with specific focus on food microbiology.
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Affiliation(s)
| | - F Hammes
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - A Canette
- INRA, UMR1319 Micalis, Jouy-en-Josas, France; AgroParisTech, UMR Micalis, Jouy-en-Josas, France
| | | | - R Briandet
- INRA, UMR1319 Micalis, Jouy-en-Josas, France; AgroParisTech, UMR Micalis, Jouy-en-Josas, France.
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50
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van Oosten M, Hahn M, Crane LMA, Pleijhuis RG, Francis KP, van Dijl JM, van Dam GM. Targeted imaging of bacterial infections: advances, hurdles and hopes. FEMS Microbiol Rev 2015; 39:892-916. [PMID: 26109599 DOI: 10.1093/femsre/fuv029] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2015] [Indexed: 02/06/2023] Open
Abstract
Bacterial infections represent an increasing problem in modern health care, in particular due to ageing populations and accumulating bacterial resistance to antibiotics. Diagnosis is rarely straightforward and consequently treatment is often delayed or indefinite. Therefore, novel tools that can be clinically implemented are urgently needed to accurately and swiftly diagnose infections. Especially, the direct imaging of infections is an attractive option. The challenge of specifically imaging bacterial infections in vivo can be met by targeting bacteria with an imaging agent. Here we review the current status of targeted imaging of bacterial infections, and we discuss advantages and disadvantages of the different approaches. Indeed, significant progress has been made in this field and the clinical implementation of targeted imaging of bacterial infections seems highly feasible. This was recently highlighted by the use of so-called smart activatable probes and a fluorescently labelled derivative of the antibiotic vancomycin. A major challenge remains the selection of the best imaging probes, and we therefore present a set of target selection criteria for clinical implementation of targeted bacterial imaging. Altogether, we conclude that the spectrum of potential applications for targeted bacterial imaging is enormous, ranging from fundamental research on infectious diseases to diagnostic and therapeutic applications.
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Affiliation(s)
- Marleen van Oosten
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands Department of Surgery, Division of Surgical Oncology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands
| | - Markus Hahn
- Department of Surgery, Division of Surgical Oncology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands
| | - Lucia M A Crane
- Department of Surgery, Division of Surgical Oncology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands
| | - Rick G Pleijhuis
- Department of Surgery, Division of Surgical Oncology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands
| | | | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands
| | - Gooitzen M van Dam
- Department of Surgery, Division of Surgical Oncology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands
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