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Kweku D, Villalba MI, Willaert RG, Yantorno OM, Vela ME, Panorska AK, Kasas S. Machine learning method for the classification of the state of living organisms' oscillations. Front Bioeng Biotechnol 2024; 12:1348106. [PMID: 38515626 PMCID: PMC10955466 DOI: 10.3389/fbioe.2024.1348106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/13/2024] [Indexed: 03/23/2024] Open
Abstract
The World Health Organization highlights the urgent need to address the global threat posed by antibiotic-resistant bacteria. Efficient and rapid detection of bacterial response to antibiotics and their virulence state is crucial for the effective treatment of bacterial infections. However, current methods for investigating bacterial antibiotic response and metabolic state are time-consuming and lack accuracy. To address these limitations, we propose a novel method for classifying bacterial virulence based on statistical analysis of nanomotion recordings. We demonstrated the method by classifying living Bordetella pertussis bacteria in the virulent or avirulence phase, and dead bacteria, based on their cellular nanomotion signal. Our method offers significant advantages over current approaches, as it is faster and more accurate. Additionally, its versatility allows for the analysis of cellular nanomotion in various applications beyond bacterial virulence classification.
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Affiliation(s)
- David Kweku
- Department of Mathematics and Statistics, University of Nevada Reno, Reno, NV, United States
| | - Maria I. Villalba
- Laboratory of Biological Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL) and University of Lausanne, Lausanne, Switzerland
- International Joint Research Group VUB-EPFL BioNanotechnology and NanoMedicine (NANO), Brussels, Switzerland
| | - Ronnie G. Willaert
- International Joint Research Group VUB-EPFL BioNanotechnology and NanoMedicine (NANO), Brussels, Switzerland
- Research Group Structural Biology Brussels, Alliance Research Group VUB-UGhent NanoMicrobiology (NAMI), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Osvaldo M. Yantorno
- Centro de Investigación y Desarrollo en Fermentaciones Industriales (CINDEFI), Facultad de Ciencias Exactas, Universidad Nacional de La Plata—CONICET, Buenos Aires, Argentina
| | - Maria E. Vela
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata—CONICET, Buenos Aires, Argentina
| | - Anna K. Panorska
- Department of Mathematics and Statistics, University of Nevada Reno, Reno, NV, United States
| | - Sandor Kasas
- Laboratory of Biological Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL) and University of Lausanne, Lausanne, Switzerland
- International Joint Research Group VUB-EPFL BioNanotechnology and NanoMedicine (NANO), Brussels, Switzerland
- Centre Universitaire Romand de Médecine Légale, Unité facultaire d’anatomie et de morphologie (UFAM), Université de Lausanne, Lausanne, Switzerland
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2
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Zając M, Kotyńska J, Zambrowski G, Breczko J, Deptuła P, Cieśluk M, Zambrzycka M, Święcicka I, Bucki R, Naumowicz M. Exposure to polystyrene nanoparticles leads to changes in the zeta potential of bacterial cells. Sci Rep 2023; 13:9552. [PMID: 37308531 DOI: 10.1038/s41598-023-36603-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 06/07/2023] [Indexed: 06/14/2023] Open
Abstract
Polymer molecules, the main components of plastics, are an emerging pollutants in various environmental compartments (water, air, soil) that may induce several ecotoxicological effects on live organisms. Therefore, understanding how plastic particles interact with bacterial cell membranes is crucial in analysing their associated risks in ecosystems and human microbiota. However, relatively little is known about the interaction between nanoplastics and bacteria. The present work focuses on Staphylococcus aureus and Klebsiella pneumoniae, representing the Gram-positive and Gram-negative bacteria respectively, exposed to 100 nm diameter polystyrene nanoparticles (PS NPs). The nanoparticles attach to the cells' membranes of both bacteria, changing their electrical charge, but without the effect of killing the cells. PS NPs caused a change in zeta potential values (both species of bacterial strains), dependent on particle concentration, pH, as well as on exposure time of bacteria to them. Through the application of AFM and FTIR techniques, the presence of PS NPs on bacterial surfaces was detected, suggesting the affinity of the particles to bacterial components, but without any changes in the morphology of the tested bacteria. The zeta potential can be more widely used in the study of interactions between nanostructures and cells.
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Affiliation(s)
- Marcin Zając
- Doctoral School of Exact and Natural Sciences, University of Bialystok, 1K K. Ciolkowski Str., 15-245, Białystok, Poland
| | - Joanna Kotyńska
- Laboratory of Bioelectrochemistry, Department of Physical Chemistry, Faculty of Chemistry, University of Bialystok, 1K K. Ciolkowski Str., 15-245, Białystok, Poland
| | - Grzegorz Zambrowski
- Laboratory of Molecular Biophysics, Department of Microbiology and Biotechnology, Faculty of Biology, University of Bialystok, 1J K. Ciolkowski Str., 15-245, Białystok, Poland
- Laboratory of Applied Microbiology, Department of Microbiology and Biotechnology, Faculty of Biology, University of Bialystok, 1J K. Ciolkowski Str., 15-245, Białystok, Poland
| | - Joanna Breczko
- Laboratory of Materials Chemistry, Department of Physical Chemistry, Faculty of Chemistry, University of Bialystok, 1K K. Ciolkowski Str., 15-245, Białystok, Poland
| | - Piotr Deptuła
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, 2C A. Mickiewicz Str., 15-222, Białystok, Poland
| | - Mateusz Cieśluk
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, 2C A. Mickiewicz Str., 15-222, Białystok, Poland
| | - Monika Zambrzycka
- Laboratory of Molecular Biophysics, Department of Microbiology and Biotechnology, Faculty of Biology, University of Bialystok, 1J K. Ciolkowski Str., 15-245, Białystok, Poland
| | - Izabela Święcicka
- Laboratory of Molecular Biophysics, Department of Microbiology and Biotechnology, Faculty of Biology, University of Bialystok, 1J K. Ciolkowski Str., 15-245, Białystok, Poland
- Laboratory of Applied Microbiology, Department of Microbiology and Biotechnology, Faculty of Biology, University of Bialystok, 1J K. Ciolkowski Str., 15-245, Białystok, Poland
| | - Robert Bucki
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, 2C A. Mickiewicz Str., 15-222, Białystok, Poland
| | - Monika Naumowicz
- Laboratory of Bioelectrochemistry, Department of Physical Chemistry, Faculty of Chemistry, University of Bialystok, 1K K. Ciolkowski Str., 15-245, Białystok, Poland.
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3
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Lin YS, Sun CL, Tsang S, Bensalem S, Le Pioufle B, Wang HY. Label-free and noninvasive analysis of microorganism surface epistructures at the single-cell level. Biophys J 2023; 122:1794-1806. [PMID: 37041747 PMCID: PMC10209039 DOI: 10.1016/j.bpj.2023.04.012] [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: 05/04/2022] [Revised: 11/10/2022] [Accepted: 04/07/2023] [Indexed: 04/13/2023] Open
Abstract
Cell surface properties of microorganisms provide abundant information for their physiological status and fate choice. However, current methods for analyzing cell surface properties require labeling or fixation, which can alter the cell activity. This study establishes a label-free, rapid, noninvasive, and quantitative analysis of cell surface properties, including the presence and the dimension of epistructure, down to the single-cell level and at the nanometer scale. Simultaneously, electrorotation provides dielectric properties of intracellular contents. With the combined information, the growth phase of microalgae cells can be identified. The measurement is based on electrorotation of single cells, and an electrorotation model accounting for the surface properties is developed to properly interpret experimental data. The epistructure length measured by electrorotation is validated by scanning electron microscopy. The measurement accuracy is satisfactory in particular in the case of microscale epistructures in the exponential phase and nanoscale epistructures in the stationary phase. However, the measurement accuracy for nanoscale epistructures on cells in the exponential phase is offset by the effect of a thick double layer. Lastly, a diversity in epistructure length distinguishes exponential phase from stationary phase.
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Affiliation(s)
- Yu-Sheng Lin
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan; Université Paris Saclay, ENS Paris Saclay, CNRS Institut d'Alembert, SATIE, Gif sur Yvette, France
| | - Chen-Li Sun
- Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
| | - Sung Tsang
- Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
| | - Sakina Bensalem
- Université Paris Saclay, ENS Paris Saclay, CNRS Institut d'Alembert, LUMIN, Gif sur Yvette, France
| | - Bruno Le Pioufle
- Université Paris Saclay, ENS Paris Saclay, CNRS Institut d'Alembert, LUMIN, Gif sur Yvette, France
| | - Hsiang-Yu Wang
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan.
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4
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Eskhan A, Johnson D. Microscale characterization of abiotic surfaces and prediction of their biofouling/anti-biofouling potential using the AFM colloidal probe technique. Adv Colloid Interface Sci 2022; 310:102796. [DOI: 10.1016/j.cis.2022.102796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 10/11/2022] [Accepted: 10/14/2022] [Indexed: 11/16/2022]
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5
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An R, Laaksonen A, Wu M, Zhu Y, Shah FU, Lu X, Ji X. Atomic force microscopy probing interactions and microstructures of ionic liquids at solid surfaces. NANOSCALE 2022; 14:11098-11128. [PMID: 35876154 DOI: 10.1039/d2nr02812c] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Ionic liquids (ILs) are room temperature molten salts that possess preeminent physicochemical properties and have shown great potential in many applications. However, the use of ILs in surface-dependent processes, e.g. energy storage, is hindered by the lack of a systematic understanding of the IL interfacial microstructure. ILs on the solid surface display rich ordering, arising from coulombic, van der Waals, solvophobic interactions, etc., all giving near-surface ILs distinct microstructures. Therefore, it is highly important to clarify the interactions of ILs with solid surfaces at the nanoscale to understand the microstructure and mechanism, providing quantitative structure-property relationships. Atomic force microscopy (AFM) opens a surface-sensitive way to probe the interaction force of ILs with solid surfaces in the layers from sub-nanometers to micrometers. Herein, this review showcases the recent progress of AFM in probing interactions and microstructures of ILs at solid interfaces, and the influence of IL characteristics, surface properties and external stimuli is thereafter discussed. Finally, a summary and perspectives are established, in which, the necessities of the quantification of IL-solid interactions at the molecular level, the development of in situ techniques closely coupled with AFM for probing IL-solid interfaces, and the combination of experiments and simulations are argued.
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Affiliation(s)
- Rong An
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Aatto Laaksonen
- Energy Engineering, Division of Energy Science, Luleå University of Technology, 97187 Luleå, Sweden.
- Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-10691 Stockholm, Sweden
- Center of Advanced Research in Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry, Iasi 700469, Romania
- State Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Muqiu Wu
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Yudan Zhu
- State Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Faiz Ullah Shah
- Chemistry of Interfaces, Luleå University of Technology, 97187 Luleå, Sweden
| | - Xiaohua Lu
- State Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Xiaoyan Ji
- Energy Engineering, Division of Energy Science, Luleå University of Technology, 97187 Luleå, Sweden.
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6
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Bilkey N, Li H, Borodinov N, Ievlev AV, Ovchinnikova OS, Dixit R, Foston M. Correlated mechanochemical maps of Arabidopsis thaliana primary cell walls using atomic force microscope infrared spectroscopy. QUANTITATIVE PLANT BIOLOGY 2022; 3:e31. [PMID: 37077971 PMCID: PMC10095902 DOI: 10.1017/qpb.2022.20] [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: 05/19/2022] [Revised: 09/11/2022] [Accepted: 10/07/2022] [Indexed: 05/03/2023]
Abstract
Spatial heterogeneity in composition and organisation of the primary cell wall affects the mechanics of cellular morphogenesis. However, directly correlating cell wall composition, organisation and mechanics has been challenging. To overcome this barrier, we applied atomic force microscopy coupled with infrared (AFM-IR) spectroscopy to generate spatially correlated maps of chemical and mechanical properties for paraformaldehyde-fixed, intact Arabidopsis thaliana epidermal cell walls. AFM-IR spectra were deconvoluted by non-negative matrix factorisation (NMF) into a linear combination of IR spectral factors representing sets of chemical groups comprising different cell wall components. This approach enables quantification of chemical composition from IR spectral signatures and visualisation of chemical heterogeneity at nanometer resolution. Cross-correlation analysis of the spatial distribution of NMFs and mechanical properties suggests that the carbohydrate composition of cell wall junctions correlates with increased local stiffness. Together, our work establishes new methodology to use AFM-IR for the mechanochemical analysis of intact plant primary cell walls.
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Affiliation(s)
- Natasha Bilkey
- Department of Biology, Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, Missouri63130, USA
| | - Huiyong Li
- Department of Energy, Environmental and Chemical Engineering, Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, Missouri63130, USA
| | - Nikolay Borodinov
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, USA
| | - Anton V. Ievlev
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, USA
| | - Olga S. Ovchinnikova
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, USA
| | - Ram Dixit
- Department of Biology, Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, Missouri63130, USA
| | - Marcus Foston
- Department of Energy, Environmental and Chemical Engineering, Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, Missouri63130, USA
- Author for correspondence: M. Foston, E-mail:
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7
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Koubali H, Latrache H, Zahir H, El Louali M. Kinetics of Adhesion
Staphylococcus aureus
on Glass in the Presence of Sodium Lauryl Sulfate. J SURFACTANTS DETERG 2020. [DOI: 10.1002/jsde.12484] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Hajar Koubali
- Laboratory of Bioprocess and Bio‐interfaces, Faculty of Sciences and Technics Sultan Moulay Slimane University B.P. 523 Beni Mellal 23000 Morocco
| | - Hassan Latrache
- Laboratory of Bioprocess and Bio‐interfaces, Faculty of Sciences and Technics Sultan Moulay Slimane University B.P. 523 Beni Mellal 23000 Morocco
| | - Hafida Zahir
- Laboratory of Bioprocess and Bio‐interfaces, Faculty of Sciences and Technics Sultan Moulay Slimane University B.P. 523 Beni Mellal 23000 Morocco
| | - Mostafa El Louali
- Laboratory of Bioprocess and Bio‐interfaces, Faculty of Sciences and Technics Sultan Moulay Slimane University B.P. 523 Beni Mellal 23000 Morocco
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8
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Hofherr L, Müller-Renno C, Ziegler C. FluidFM as a tool to study adhesion forces of bacteria - Optimization of parameters and comparison to conventional bacterial probe Scanning Force Spectroscopy. PLoS One 2020; 15:e0227395. [PMID: 32628681 PMCID: PMC7337302 DOI: 10.1371/journal.pone.0227395] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 05/28/2020] [Indexed: 12/03/2022] Open
Abstract
The FluidFM enables the immobilization of single cells on a hollow cantilever using relative underpressure. In this study, we systematically optimize versatile measurement parameters (setpoint, z-speed, z-length, pause time, and relative underpressure) to improve the quality of force-distance curves recorded with a FluidFM. Using single bacterial cells (here the gram negative seawater bacterium Paracoccus seriniphilus and the gram positive bacterium Lactococcus lactis), we show that Single Cell Force Spectroscopy experiments with the FluidFM lead to comparable results to a conventional Single Cell Force Spectroscopy approach using polydopamine for chemical fixation of a bacterial cell on a tipless cantilever. Even for the bacterium Lactococcus lactis, which is difficult to immobilze chemically (like seen in an earlier study), immobilization and the measurement of force-distance curves are possible by using the FluidFM technology.
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Affiliation(s)
- Linda Hofherr
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Kaiserslautern, Germany
| | - Christine Müller-Renno
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Kaiserslautern, Germany
- * E-mail:
| | - Christiane Ziegler
- Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Kaiserslautern, Germany
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9
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Overton K, Greer HM, Ferguson MA, Spain EM, Elmore DE, Núñez ME, Volle CB. Qualitative and Quantitative Changes to Escherichia coli during Treatment with Magainin 2 Observed in Native Conditions by Atomic Force Microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:650-659. [PMID: 31876422 PMCID: PMC7430157 DOI: 10.1021/acs.langmuir.9b02726] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The bacterial membrane has been suggested as a good target for future antibiotics, so it is important to understand how naturally occurring antibiotics like antimicrobial peptides (AMPs) disrupt those membranes. The interaction of the AMP magainin 2 (MAG2) with the bacterial cell membrane has been well characterized using supported lipid substrates, unilamellar vesicles, and spheroplasts created from bacterial cells. However, to fully understand how MAG2 kills bacteria, we must consider its effect on the outer membrane found in Gram-negative bacteria. Here, we use atomic force microscopy (AFM) to directly investigate MAG2 interaction with the outer membrane of Escherichia coli and characterize the biophysical consequences of MAG2 treatment under native conditions. While propidium iodide penetration indicates that MAG2 permeabilizes cells within seconds, a corresponding decrease in cellular turgor pressure is not observed until minutes after MAG2 application, suggesting that cellular homeostasis machinery may be responsible for helping the cell maintain turgor pressure despite a loss of membrane integrity. AFM imaging and force measurement modes applied in tandem reveal that the outer membrane becomes pitted, more flexible, and more adhesive after MAG2 treatment. MAG2 appears to have a highly disruptive effect on the outer membrane, extending the known mechanism of MAG2 to the Gram-negative outer membrane.
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Affiliation(s)
- Kanesha Overton
- Department of Biology , Cottey College , 1000 West Austin Boulevard , Nevada , Missouri 64772 , United States
| | - Helen M Greer
- Department of Biology , Cottey College , 1000 West Austin Boulevard , Nevada , Missouri 64772 , United States
| | - Megan A Ferguson
- Department of Chemistry , State University of New York , 1 Hawk Drive , New Paltz , New York 12561 , United States
| | - Eileen M Spain
- Department of Chemistry , Occidental College , 1600 Campus Road , Los Angeles , California 90041 , United States
| | - Donald E Elmore
- Department of Chemistry and Program in Biochemistry , Wellesley College , 106 Central Street , Wellesley , Massachusetts 02481 , United States
| | - Megan E Núñez
- Department of Chemistry and Program in Biochemistry , Wellesley College , 106 Central Street , Wellesley , Massachusetts 02481 , United States
| | - Catherine B Volle
- Department of Biology , Cottey College , 1000 West Austin Boulevard , Nevada , Missouri 64772 , United States
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10
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Probing the surface ultrastructure of Brevibacillus laterosporus using atomic force microscopy. Micron 2020; 131:102827. [PMID: 31951938 DOI: 10.1016/j.micron.2020.102827] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 01/12/2020] [Accepted: 01/12/2020] [Indexed: 11/21/2022]
Abstract
One of the main obstacles to studying the surface ultrastructure of microbial cells by atomic force microscopy (AFM) is determining how to immobilize live cells on the AFM substrates. Each method has its own advantages and disadvantages. The aim of this study was to characterize a new simple and inexpensive method using two types of polyethersulfone (PES) membrane filters that differ in pore size (micropore and nanopore) to immobilize live and dead Brevibacillus laterosporus for AFM imaging. B. laterosporus was easily trapped by the microporous PES membrane, facilitating the successful AFM scanning of the bacterial surface ultrastructure. In addition, B. laterosporus strongly attached to the nanoporous membranes and withstood the pulling forces exerted by the AFM tip during scanning. These methods of immobilization did not affect the cell viability. The nanostructure and roughness of the bacterial surface were also observed for live, fixed, and air-dried cells. Live and dead bacteria displayed similar morphologies at low resolution, while at high resolution, live bacteria displayed a more convoluted surface ("brain-like structure").
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11
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Visser MJ, Pretorius E. Atomic Force Microscopy: The Characterisation of Amyloid Protein Structure in Pathology. Curr Top Med Chem 2020; 19:2958-2973. [DOI: 10.2174/1568026619666191121143240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/24/2019] [Accepted: 09/27/2019] [Indexed: 12/28/2022]
Abstract
:
Proteins are versatile macromolecules that perform a variety of functions and participate in
virtually all cellular processes. The functionality of a protein greatly depends on its structure and alterations
may result in the development of diseases. Most well-known of these are protein misfolding disorders,
which include Alzheimer’s and Parkinson’s diseases as well as type 2 diabetes mellitus, where
soluble proteins transition into insoluble amyloid fibrils. Atomic Force Microscopy (AFM) is capable of
providing a topographical map of the protein and/or its aggregates, as well as probing the nanomechanical
properties of a sample. Moreover, AFM requires relatively simple sample preparation, which presents
the possibility of combining this technique with other research modalities, such as confocal laser
scanning microscopy, Raman spectroscopy and stimulated emission depletion microscopy. In this review,
the basic principles of AFM are discussed, followed by a brief overview of how it has been applied
in biological research. Finally, we focus specifically on its use as a characterisation method to
study protein structure at the nanoscale in pathophysiological conditions, considering both molecules
implicated in disease pathogenesis and the plasma protein fibrinogen. In conclusion, AFM is a userfriendly
tool that supplies multi-parametric data, rendering it a most valuable technique.
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Affiliation(s)
- Maria J.E. Visser
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
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12
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Goss JW, Volle CB. Using Atomic Force Microscopy To Illuminate the Biophysical Properties of Microbes. ACS APPLIED BIO MATERIALS 2019; 3:143-155. [PMID: 32851362 DOI: 10.1021/acsabm.9b00973] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Since its invention in 1986, atomic force microscopy (AFM) has grown from a system designed for imaging inorganic surfaces to a tool used to probe the biophysical properties of living cells and tissues. AFM is a scanning probe technique and uses a pyramidal tip attached to a flexible cantilever to scan across a surface, producing a highly detailed image. While many research articles include AFM images, fewer include force-distance curves, from which several biophysical properties can be determined. In a single force-distance curve, the cantilever is lowered and raised from the surface, while the forces between the tip and the surface are monitored. Modern AFM has a wide variety of applications, but this review will focus on exploring the mechanobiology of microbes, which we believe is of particular interest to those studying biomaterials. We briefly discuss experimental design as well as different ways of extracting meaningful values related to cell surface elasticity, cell stiffness, and cell adhesion from force-distance curves. We also highlight both classic and recent experiments using AFM to illuminate microbial biophysical properties.
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Affiliation(s)
- John W Goss
- Department of Biological Sciences, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Catherine B Volle
- Departments of Biology and Chemistry, Cornell College, Mount Vernon, Iowa 52314, United States
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13
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Differential homotypic and heterotypic interactions of antigen 43 (Ag43) variants in autotransporter-mediated bacterial autoaggregation. Sci Rep 2019; 9:11100. [PMID: 31367003 PMCID: PMC6668479 DOI: 10.1038/s41598-019-47608-4] [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: 03/05/2019] [Accepted: 06/18/2019] [Indexed: 12/18/2022] Open
Abstract
Antigen 43 (Ag43) is a cell-surface exposed protein of Escherichia coli secreted by the Type V, subtype a, secretion system (T5aSS) and belonging to the family of self-associating autotransporters (SAATs). These modular proteins, comprising a cleavable N-terminal signal peptide, a surface-exposed central passenger and an outer membrane C-terminal translocator, self-recognise in a Velcro-like handshake mechanism. A phylogenetic network analysis focusing on the passenger revealed for the first time that they actually distribute into four distinct classes, namely C1, C2, C3 and C4. Structural alignment and modelling analyses demonstrated these classes arose from shuffling of two different subdomains within the Ag43 passengers. Functional analyses revealed that homotypic interactions occur for all Ag43 classes but significant differences in the sedimentation kinetics and aggregation state were present when Ag43C3 was expressed. In contrast, heterotypic interaction occurred in a very limited number of cases. Single cell-force spectroscopy demonstrated the importance of specific as well as nonspecific interactions in mediating Ag43-Ag43 recognition. We propose that structural differences in the subdomains of the Ag43 classes account for different autoaggregation dynamics and propensities to co-interact.
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14
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Velic A, Tesfamichael T, Li Z, Yarlagadda PK. Parametric Study on Nanopattern Bactericidal Activity. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.promfg.2019.02.072] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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15
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Li J, Zheng C, Liu B, Chou T, Kim Y, Qiu S, Li J, Yan W, Fu J. Controlled graphene encapsulation: a nanoscale shield for characterising single bacterial cells in liquid. NANOTECHNOLOGY 2018; 29:365705. [PMID: 29889049 DOI: 10.1088/1361-6528/aacba7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
High-resolution single-cell imaging in their native or near-native state has received considerable interest for decades. In this research, we present an innovative approach that can be employed to study both morphological and nano-mechanical properties of hydrated single bacterial cells. The proposed strategy is to encapsulate wet cells with monolayer graphene with a newly developed water membrane approach, followed by imaging with both electron microscopy (EM) and atomic force microscopy (AFM). A computational framework was developed to provide additional insights, with the detailed nanoindentation process on graphene modelled based on the finite element method. The model was first validated by calibration with polymer materials of known properties, and the contribution of graphene was then studied and corrected to determine the actual moduli of the encapsulated hydrated sample. Application of the proposed approach was performed on hydrated bacterial cells (Klebsiella pneumoniae) to correlate the structural and mechanical information. EM and energy-dispersive x-ray spectroscopy imaging confirmed that the cells in their near-native stage can be studied inside the miniaturised environment enabled with graphene encapsulation. The actual moduli of the encapsulated hydrated cells were determined based on the developed computational model in parallel, with results comparable with those acquired with wet AFM. It is expected that the successful establishment of controlled graphene encapsulation offers a new route for probing liquid/live cells with scanning probe microscopy, as well as correlative imaging of hydrated samples for both biological and material sciences.
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Affiliation(s)
- Jiayao Li
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia
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16
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Isolation and characterization of a novel 1-aminocyclopropane-1-carboxylate (ACC) deaminase producing plant growth promoting marine Gammaproteobacteria from crops grown in brackish environments. Proposal for Pokkaliibacter plantistimulans gen. nov., sp. nov., Balneatrichaceae fam. nov. in the order Oceanospirillales and an emended description of the genus Balneatrix. Syst Appl Microbiol 2018; 41:570-580. [PMID: 30139512 DOI: 10.1016/j.syapm.2018.08.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/30/2018] [Accepted: 08/04/2018] [Indexed: 11/22/2022]
Abstract
Three novel strains namely, L1E11T, L1E4 and 228 were isolated as part of an ongoing study on 1-aminocyclopropane-1-carboxylate (ACC) deaminase expressing rhizobacteria from crops cultivated in saline affected coastal agro-ecosystems of Kerala, India. The novel strains were positive for many properties that are beneficial to plant growth including ACC deaminase (ACCd) activity that ranged from 1.87±0.27 to 2.88±0.71μmol of α-ketobutyrate/hr/mg of total protein. Presence of other traits such as biofilm formation, siderophore production, phosphate solubilisation, utilisation of root derived compounds and ability to colonise host roots indicates its plant-associated life style. In complement, the genomic data reveals gene features for higher adaptation to plant-associated environments. In-planta assays showed that L1E11T can promote and protect pokkali rice plants from 200mM NaCl stress. Phylogenetic, chemotaxonomic, phenotypic and genomic characterisation indicates that the novel strains belong to a novel genus and species of the order Oceanospirillales for which the names Pokkaliibacter gen. nov., and Pokkaliibacter plantistimulans sp. nov., are proposed with L1E11T (=DSM 28732T=MCC 2992T) as the type strain. Further, on the basis of low 16S rRNA sequence similarity, phylogenetic divergence, source of isolation and few differences in the phenotypic properties against its nearest taxon, a new family Balneatrichaceae fam. nov., is proposed to accommodate the two genera Balneatrix and Pokkaliibacter gen.nov. with Balneatrix as the type genus. An emended description of the genus Balneatrix is also presented.
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17
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Rasheed W, Perveen S, Mustafa G, Shah MR, Ahmed S, Uzzaman S. Impact of Cu(II)-doping on the vulnerability of Escherichia coli ATCC 10536 revealed by Atomic Force Microscopy. Micron 2018; 110:73-78. [PMID: 29772475 DOI: 10.1016/j.micron.2018.05.002] [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] [Received: 03/21/2018] [Revised: 05/02/2018] [Accepted: 05/03/2018] [Indexed: 11/28/2022]
Abstract
E. coli strain is a gram-negative bacterium known to induce both extra-intestinal infections and intestinal infections. For survival of microbes, metal intake and accessibility should be according to their physiological requirements. Peculiarly, copper homeostasis is critical for E. coli survival and growth. Therefore in this study, an extensive work is conducted to investigate the impact of Cu(II)-doping on the susceptibility of Escherichia coli ATCC 10536 against Cu(II)-selective Cefaclor-silver nanoconjugates (i.e., Cf-AgNPs) and its organic precursor (i.e. Cefaclor). At first, the maximal non-cytotoxic dose of Cu(II) that was sub-lethal for Escherichia coli was determined by MTT assay and was found to be 100 μg/L. Afterwards, MICs of Cf-AgNPs and Cefaclor against controlled and Cu(II)-doped E. coli cells were determined by using Agar well diffusion method. The susceptibility of E. coli cells against Cf-AgNPs was increased upon Cu(II) doping, whereas the bactericidal activity of Cefaclor against Cu(II)-doped E. coli cells was retarded due to hydrolysis. In addition, morphological changes induced in controlled and Cu(II)-doped samples of E. coli after treatment with Cefaclor and Cf-AgNPs were also monitored by Atomic force microscopy (AFM). The obtained results from both Agar well diffusion method and AFM confirmed that Cf-AgNPs are more effective against Cu(II)-doped Escherichia coli. Moreover, thermal profile of Cu(II)-selective Cf-AgNPs was also demonstrated by TGA and DSC. This study can be an important part of the relevant state-of-the-art. Indeed, further clinical studies are necessary to determine the relevant role of Cf-AgNPs compared with that of the Cefaclor now available.
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Affiliation(s)
- Wasia Rasheed
- Department of Applied Chemistry and Chemical Technology, University of Karachi, Karachi, 75270, Pakistan; H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan.
| | - Samina Perveen
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Ghulam Mustafa
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Muhammad Raza Shah
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Shakil Ahmed
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Sami Uzzaman
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
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18
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Rasheed W, Shah MR, Perveen S, Ahmed S, Uzzaman S. Revelation of susceptibility differences due to Hg(II) accumulation in Streptococcus pyogenes against CX-AgNPs and Cefixime by atomic force microscopy. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 147:9-16. [PMID: 28822261 DOI: 10.1016/j.ecoenv.2017.08.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 08/08/2017] [Accepted: 08/12/2017] [Indexed: 06/07/2023]
Abstract
Solution based method for the formation of chemically modified silver nanoparticles (CX-AgNPs) using Cefixime as stabilizing and reducing agent was developed. The CX-AgNPs were characterized by AFM, UV-visible, FT-IR and MALDI-TOF MS. Bactericidal efficiency of CX-AgNPs and Cefixime against Streptococcus pyogenes was evaluated. Afterwards, susceptibility differences of Streptococcus pyogenes due to accumulation of Hg(II) against CX-AgNPs and Cefixime were estimated and validated through Atomic force microscopy. Selectivity and sensitivity of CX-AgNPs against Hg(II) was evaluated in a systematic manner. The CX-AgNPs was titrated against optically silent Hg(II) which induced enhancement in the SPR band of CX-AgNPs. The increase in intensity of SPR band of CX-AgNPs was determined to be proportionate to the concentration of Hg(II) in the range of 33.3-700µM obeying linear regression equation of y = 0.125x + 8.962 with the detection limit of 0.10µM and the coefficient of determination equals to 0.985 (n = 3). The association constant Ka of CX-AgNPs-Hg(II) was found to be 386.0095mol-1dm3 by using the Benesi Hildebrand plot.
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Affiliation(s)
- Wasia Rasheed
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Muhammad Raza Shah
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
| | - Samina Perveen
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Shakil Ahmed
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Sami Uzzaman
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
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19
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Li Q, Becker T, Sand W. Quantification of cell-substratum interactions by atomic force microscopy. Colloids Surf B Biointerfaces 2017; 159:639-643. [PMID: 28865360 DOI: 10.1016/j.colsurfb.2017.08.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Revised: 08/08/2017] [Accepted: 08/14/2017] [Indexed: 11/15/2022]
Abstract
Microorganisms adhere to surfaces and, subsequently, form biofilms. This process is of major interest in biotechnology, environmental sciences and medicine. It is crucial to understand the mechanisms of interactions between substratum and cells or biofilms. By combining force mapping-based atomic force microscopy (AFM) with pyrite-modified cantilevers we quantified the adhesion forces between undenatured planktonic or biofilm cells of Sulfobacillus thermosulfidooxidans and the substratum pyrite with values of 2.6±0.3nN and 77.3±7.1pN, respectively. This was achieved under natural conditions without any artefact resulting from the use of denaturing chemicals such as glutaraldehyde. This new technique is unique for quantifying the real interaction forces between cells or biofilms and their substrata.
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Affiliation(s)
- Qian Li
- Biofilm Centre, Aquatische Biotechnologie, Universität Duisburg-Essen, Universitätsstraße 5, 45141 Essen, Germany
| | - Thomas Becker
- Department of Chemistry/Nanochemistry Research Institute, Curtin University, Bentley, WA 6845, Australia
| | - Wolfgang Sand
- Biofilm Centre, Aquatische Biotechnologie, Universität Duisburg-Essen, Universitätsstraße 5, 45141 Essen, Germany; College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China.
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20
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Rostam HM, Reynolds PM, Alexander MR, Gadegaard N, Ghaemmaghami AM. Image based Machine Learning for identification of macrophage subsets. Sci Rep 2017; 7:3521. [PMID: 28615717 PMCID: PMC5471192 DOI: 10.1038/s41598-017-03780-z] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 05/03/2017] [Indexed: 11/29/2022] Open
Abstract
Macrophages play a crucial rule in orchestrating immune responses against pathogens and foreign materials. Macrophages have remarkable plasticity in response to environmental cues and are able to acquire a spectrum of activation status, best exemplified by pro-inflammatory (M1) and anti-inflammatory (M2) phenotypes at the two ends of the spectrum. Characterisation of M1 and M2 subsets is usually carried out by quantification of multiple cell surface markers, transcription factors and cytokine profiles. These approaches are time-consuming, require large numbers of cells and are resource intensive. In this study, we used machine learning algorithms to develop a simple and fast imaging-based approach that enables automated identification of different macrophage functional phenotypes using their cell size and morphology. Fluorescent microscopy was used to assess cell morphology of different cell types which were stained for nucleus and actin distribution using DAPI and phalloidin respectively. By only analysing their morphology we were able to identify M1 and M2 phenotypes effectively and could distinguish them from naïve macrophages and monocytes with an average accuracy of 90%. Thus we suggest high-content and automated image analysis can be used for fast phenotyping of functionally diverse cell populations with reasonable accuracy and without the need for using multiple markers.
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Affiliation(s)
- Hassan M Rostam
- Division of Immunology, School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, NG7 2RD, UK.,Department of Biology, University of Garmian, Kalar, Kurdistan, Iraq
| | - Paul M Reynolds
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK
| | - Morgan R Alexander
- Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Nikolaj Gadegaard
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK.
| | - Amir M Ghaemmaghami
- Division of Immunology, School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, NG7 2RD, UK.
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21
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James SA, Hilal N, Wright CJ. Atomic force microscopy studies of bioprocess engineering surfaces - imaging, interactions and mechanical properties mediating bacterial adhesion. Biotechnol J 2017; 12. [PMID: 28488793 DOI: 10.1002/biot.201600698] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 03/24/2017] [Accepted: 04/10/2017] [Indexed: 12/19/2022]
Abstract
The detrimental effect of bacterial biofilms on process engineering surfaces is well documented. Thus, interest in the early stages of bacterial biofilm formation; in particular bacterial adhesion and the production of anti-fouling coatings has grown exponentially as a field. During this time, Atomic force microscopy (AFM) has emerged as a critical tool for the evaluation of bacterial adhesion. Due to its versatility AFM offers not only insight into the topographical landscape and mechanical properties of the engineering surfaces, but elucidates, through direct quantification the topographical and biomechnical properties of the foulants The aim of this review is to collate the current research on bacterial adhesion, both theoretical and practical, and outline how AFM as a technique is uniquely equipped to provide further insight into the nanoscale world at the bioprocess engineering surface.
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Affiliation(s)
- Sean A James
- Biomaterials, Biofouling and Biofilms Engineering Laboratory (B3EL, System and Process Engineering Center, College of Engineering, Swansea University, Fabian Way, Swansea, SA1 8EN, UK
| | - Nidal Hilal
- Centre for Water Advanced Technologies and Environmental Research (CWATER), College of Engineering, Swansea University, Fabian Way, Swansea, SA1 8EN, UK
| | - Chris J Wright
- Biomaterials, Biofouling and Biofilms Engineering Laboratory (B3EL, System and Process Engineering Center, College of Engineering, Swansea University, Fabian Way, Swansea, SA1 8EN, UK
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22
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Nolte TM, Hartmann NB, Kleijn JM, Garnæs J, van de Meent D, Jan Hendriks A, Baun A. The toxicity of plastic nanoparticles to green algae as influenced by surface modification, medium hardness and cellular adsorption. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 183:11-20. [PMID: 27978483 DOI: 10.1016/j.aquatox.2016.12.005] [Citation(s) in RCA: 209] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 11/29/2016] [Accepted: 12/07/2016] [Indexed: 06/06/2023]
Abstract
To investigate processes possibly underlying accumulation and ecological effects of plastic nano-particles we have characterized their interaction with the cell wall of green algae. More specifically, we have investigated the influence of particle surface functionality and water hardness (Ca2+ concentration) on particle adsorption to algae cell walls. Polystyrene nanoparticles with different functional groups (non-functionalized, -COOH and -NH2) as well as coated (starch and PEG) gold nanoparticles were applied in these studies. Depletion measurements and atomic force microscopy (AFM) showed that adsorption of neutral and positively charged plastic nanoparticles onto the cell wall of P. subcapitata was stronger than that of negatively charged plastic particles. Results indicated that binding affinity is a function of both inter-particle and particle-cell wall interactions which are in turn influenced by the medium hardness and particle concentration. Physicochemical modelling using DLVO theory was used to interpret the experimental data, using also values for interfacial surface free energies. Our study shows that material properties and medium conditions play a crucial role in the rate and state of nanoparticle bio-adsorption for green algae. The results show that the toxicity of nanoparticles can be better described and assessed by using appropriate dose metrics including material properties, complexation/agglomeration behavior and cellular attachment and adsorption. The applied methodology provides an efficient and feasible approach for evaluating potential accumulation and hazardous effects of nanoparticles to algae caused by particle interactions with the algae cell walls.
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Affiliation(s)
- Tom M Nolte
- Department of Environmental Engineering, Technical University of Denmark, Miljøvej, B113, 2800 Kgs. Lyngby, Denmark; Radboud University Nijmegen, Institute for Water and Wetland Research, Department of Environmental Science, P.O. Box 9010, NL-6500 GL, Nijmegen, The Netherlands.
| | - Nanna B Hartmann
- Department of Environmental Engineering, Technical University of Denmark, Miljøvej, B113, 2800 Kgs. Lyngby, Denmark
| | - J Mieke Kleijn
- Physical Chemistry Soft Matter, Wageningen University, Stippeneng 4, NL-6708WE Wageningen, The Netherlands
| | - Jørgen Garnæs
- Danish Fundamental Metrology, Matematiktorvet 307, 2800 Kgs. Lyngby, Denmark
| | - Dik van de Meent
- Radboud University Nijmegen, Institute for Water and Wetland Research, Department of Environmental Science, P.O. Box 9010, NL-6500 GL, Nijmegen, The Netherlands; National Institute of Public Health and the Environment RIVM, P.O. Box 1, 3720 BA, Bilthoven, The Netherlands
| | - A Jan Hendriks
- Radboud University Nijmegen, Institute for Water and Wetland Research, Department of Environmental Science, P.O. Box 9010, NL-6500 GL, Nijmegen, The Netherlands
| | - Anders Baun
- Department of Environmental Engineering, Technical University of Denmark, Miljøvej, B113, 2800 Kgs. Lyngby, Denmark
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23
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Atomic force microscopy for the investigation of molecular and cellular behavior. Micron 2016; 89:60-76. [DOI: 10.1016/j.micron.2016.07.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/27/2016] [Indexed: 12/19/2022]
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24
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Abdelhady HG, Abdel-Salam HA, Niazy EM, Mueller A, Quast MJ, Effat AM, Elbehairi SEI. Spatiotemporal PFQNM visualization of the effect of suicide dendriplexes on dividing HeLa cells. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2016; 12:2365-2371. [PMID: 27389145 DOI: 10.1016/j.nano.2016.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/09/2016] [Accepted: 06/09/2016] [Indexed: 10/21/2022]
Abstract
Suicide gene delivery is significant in cancer therapy but has not been fully investigated on a cellular scale. Here, Peak Force Quantitative Nanomechanical atomic force microscopy (PFQNM-AFM) was applied to visualize the effect of herpes simplex virus thymidine kinase dendriplexes (G4AcFaHSTK) on the morphological and nanomechanical properties of individual live and dividing HeLa cells. Cells were then exposed to G4AcFaHSTK, followed by ganciclovir, and directly imaged by real-time PFQNM-AFM. Cell membrane liquefaction, cytoplasmic shrinkage, and cytoskeleton structure loss were observed during cell division. The average Young's modulus of the nuclear region increased with time as the cell continued from metaphase (6.29 kPa) to telophase (13.6 kPa) and then decreased (2.25 kPa) upon apoptosis. In contrast, cells exposed to either ganciclovir or G4AcFaHSTK alone have no changes. Thus, understanding the real-time effects of suicide dendriplexes on the cytoskeletal and nanomechanical behaviors of cancer cells may provide new methods for cancer treatment.
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Affiliation(s)
- Hosam G Abdelhady
- Pharmaceutics and Pharmaceutical Technology, College of Pharmacy-Taibah University, Al-Madinah Al-Munawwarah, Saudi Arabia; Bioavailability Center, National Organization for Drug Control and Research, Agouza, Giza, Egypt.
| | - Hassan A Abdel-Salam
- Pharmaceutics and Pharmaceutical Technology, College of Pharmacy-Taibah University, Al-Madinah Al-Munawwarah, Saudi Arabia; Department of Microbiology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Esmaeel M Niazy
- Pharmaceutics and Pharmaceutical Technology, College of Pharmacy-Taibah University, Al-Madinah Al-Munawwarah, Saudi Arabia
| | - Anja Mueller
- Department of Chemistry, Central Michigan University, Mount Pleasant, MI, USA
| | - Matthew J Quast
- Department of Chemistry, Central Michigan University, Mount Pleasant, MI, USA
| | - Ahmed M Effat
- Pharmaceutics and Pharmaceutical Technology, College of Pharmacy-Taibah University, Al-Madinah Al-Munawwarah, Saudi Arabia
| | - Serag-Eldin I Elbehairi
- Cell Culture Laboratory, Egyptian Organization for Biological Products and Vaccines, Agouza, Giza, Egypt; Biology Department, Faculty of Science, King Khalid University, Abha, Saudi Arabia
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25
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Tajkarimi M, Harrison SH, Hung AM, Graves JL. Mechanobiology of Antimicrobial Resistant Escherichia coli and Listeria innocua. PLoS One 2016; 11:e0149769. [PMID: 26914334 PMCID: PMC4767320 DOI: 10.1371/journal.pone.0149769] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 02/02/2016] [Indexed: 11/18/2022] Open
Abstract
A majority of antibiotic-resistant bacterial infections in the United States are associated with biofilms. Nanoscale biophysical measures are increasingly revealing that adhesive and viscoelastic properties of bacteria play essential roles across multiple stages of biofilm development. Atomic Force Microscopy (AFM) applied to strains with variation in antimicrobial resistance enables new opportunities for investigating the function of adhesive forces (stickiness) in biofilm formation. AFM force spectroscopy analysis of a field strain of Listeria innocua and the strain Escherichia coli K-12 MG1655 revealed differing adhesive forces between antimicrobial resistant and nonresistant strains. Significant increases in stickiness were found at the nanonewton level for strains of Listeria innocua and Escherichia coli in association with benzalkonium chloride and silver nanoparticle resistance respectively. This advancement in the usage of AFM provides for a fast and reliable avenue for analyzing antimicrobial resistant cells and the molecular dynamics of biofilm formation as a protective mechanism.
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Affiliation(s)
- Mehrdad Tajkarimi
- Department of Nanoscience, Joint School for Nanoscience & Nanoengineering, Greensboro, North Carolina, United States of America
| | - Scott H. Harrison
- Department of Biology, North Carolina A&T State University, Greensboro, North Carolina, United States of America
| | - Albert M. Hung
- Department of Nanoengineering, Joint School for Nanoscience & Nanoengineering, North Carolina A&T State University & UNC Greensboro, Greensboro, North Carolina, United States of America
| | - Joseph L. Graves
- Department of Biology, North Carolina A&T State University, Greensboro, North Carolina, United States of America
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Arnal L, Longo G, Stupar P, Castez MF, Cattelan N, Salvarezza RC, Yantorno OM, Kasas S, Vela ME. Localization of adhesins on the surface of a pathogenic bacterial envelope through atomic force microscopy. NANOSCALE 2015; 7:17563-17572. [PMID: 26446736 DOI: 10.1039/c5nr04644k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Bacterial adhesion is the first and a significant step in establishing infection. This adhesion normally occurs in the presence of flow of fluids. Therefore, bacterial adhesins must be able to provide high strength interactions with their target surface in order to maintain the adhered bacteria under hydromechanical stressing conditions. In the case of B. pertussis, a Gram-negative bacterium responsible for pertussis, a highly contagious human respiratory tract infection, an important protein participating in the adhesion process is a 220 kDa adhesin named filamentous haemagglutinin (FHA), an outer membrane and also secreted protein that contains recognition domains to adhere to ciliated respiratory epithelial cells and macrophages. In this work, we obtained information on the cell-surface localization and distribution of the B. pertussis adhesin FHA using an antibody-functionalized AFM tip. Through the analysis of specific molecular recognition events we built a map of the spatial distribution of the adhesin which revealed a non-homogeneous pattern. Moreover, our experiments showed a force induced reorganization of the adhesin on the surface of the cells, which could explain a reinforced adhesive response under external forces. This single-molecule information contributes to the understanding of basic molecular mechanisms used by bacterial pathogens to cause infectious disease and to gain insights into the structural features by which adhesins can act as force sensors under mechanical shear conditions.
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Affiliation(s)
- L Arnal
- Centro de Investigación y Desarrollo de Fermentaciones Industriales (CINDEFI-CONICET-CCT La Plata), Facultad de Ciencias Exactas, UNLP. 50 No 227, 1900 La Plata, Argentina
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27
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Abstract
Endodontic disease is a biofilm-mediated infection, and primary aim in the management of endodontic disease is the elimination of bacterial biofilm from the root canal system. The most common endodontic infection is caused by the surface-associated growth of microorganisms. It is important to apply the biofilm concept to endodontic microbiology to understand the pathogenic potential of the root canal microbiota as well as to form the basis for new approaches for disinfection. It is foremost to understand how the biofilm formed by root canal bacteria resists endodontic treatment measures. Bacterial etiology has been confirmed for common oral diseases such as caries and periodontal and endodontic infections. Bacteria causing these diseases are organized in biofilm structures, which are complex microbial communities composed of a great variety of bacteria with different ecological requirements and pathogenic potential. The biofilm community not only gives bacteria effective protection against the host's defense system but also makes them more resistant to a variety of disinfecting agents used as oral hygiene products or in the treatment of infections. Successful treatment of these diseases depends on biofilm removal as well as effective killing of biofilm bacteria. So, the fundamental to maintain oral health and prevent dental caries, gingivitis, and periodontitis is to control the oral biofilms. From these aspects, the formation of biofilms carries particular clinical significance because not only host defense mechanisms but also therapeutic efforts including chemical and mechanical antimicrobial treatment measures have the most difficult task of dealing with organisms that are gathered in a biofilm. The aim of this article was to review the mechanisms of biofilms’ formation, their roles in pulpal and periapical pathosis, the different types of biofilms, the factors influencing biofilm formation, the mechanisms of their antimicrobial resistance, techniques to identify biofilms.
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Affiliation(s)
- Kapil Jhajharia
- Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Melaka Manipal Medical College, Melaka, Malaysia
| | - Abhishek Parolia
- Department of Restorative Dentistry, Faculty of Dentistry, International Medical University, Kuala Lumpur, Malaysia
| | - K Vikram Shetty
- Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Melaka Manipal Medical College, Melaka, Malaysia
| | - Lata Kiran Mehta
- Department of Pedodontics and Preventive Dentistry, P. D. M. Dental College and Research Institute, Jhajjar, Haryana, India
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28
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Zeng G, Müller T, Meyer RL. Single-cell force spectroscopy of bacteria enabled by naturally derived proteins. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:4019-4025. [PMID: 24654836 DOI: 10.1021/la404673q] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Bringing the study of bacterial adhesion down to a single-cell level is critical for understanding the molecular mechanisms involved in initial bacterial attachment. We have developed a simple and versatile method for making single-cell bacterial probes to study the adhesion of single bacterial cells by atomic force microscopy (AFM). A single-cell probe was made by picking up a bacterial cell from a glass surface using a tipless AFM cantilever coated with a commercial cell adhesive Cell-Tak. The method was applied to four different bacterial strains, and single-cell adhesion was measured on three surfaces (fresh glass, hydrophilic glass, and mica). Attachment to the cantilever was stable during the AFM force measurements that were conducted for 2 h, and viability was confirmed by Live/Dead fluorescence staining at the end of each experiment. The adhesion force and final rupture length were dependent on bacterial strains, surfaces properties, and contact time. The single-cell probe offers control of cell immobilization and thus holds advantages over the commonly used multicell probes with which random immobilization is obtained by submerging the cantilever in a bacterial suspension. The reported method provides a general platform for investigating single-cell interactions of bacteria with different surfaces and other cells by AFM force spectroscopy, thus improving our understanding of the mechanisms of bacterial attachment.
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Affiliation(s)
- Guanghong Zeng
- Interdisciplinary Nanoscience Center (iNANO), Faculty of Science and Technology, Aarhus University , Aarhus 8000, Denmark
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Lu S, Walters G, Parg R, Dutcher JR. Nanomechanical response of bacterial cells to cationic antimicrobial peptides. SOFT MATTER 2014; 10:1806-1815. [PMID: 24652481 DOI: 10.1039/c3sm52801d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The effectiveness of antimicrobial compounds can be easily screened, however their mechanism of action is much more difficult to determine. Many compounds act by compromising the mechanical integrity of the bacterial cell envelope, and our study introduces an AFM-based creep deformation technique to evaluate changes in the time-dependent mechanical properties of Pseudomonas aeruginosa PAO1 bacterial cells upon exposure to two different but structurally related antimicrobial peptides. We observed a distinctive signature for the loss of integrity of the bacterial cell envelope following exposure to the peptides. Measurements performed before and after exposure, as well as time-resolved measurements and those performed at different concentrations, revealed large changes to the viscoelastic parameters that are consistent with differences in the membrane permeabilizing effects of the peptides. The AFM creep deformation measurement provides new, unique insight into the kinetics and mechanism of action of antimicrobial peptides on bacteria.
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Affiliation(s)
- Shun Lu
- Department of Physics, University of Guelph, Guelph, N1G 2W1, Ontario, Canada.
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Kuyukina MS, Korshunova IO, Rubtsova EV, Ivshina IB. Methods of microorganism immobilization for dynamic atomic-force studies (review). APPL BIOCHEM MICRO+ 2013. [DOI: 10.1134/s0003683814010086] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Multiparametric atomic force microscopy imaging of single bacteriophages extruding from living bacteria. Nat Commun 2013; 4:2926. [DOI: 10.1038/ncomms3926] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 11/13/2013] [Indexed: 12/25/2022] Open
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Nanoscale cell wall deformation impacts long-range bacterial adhesion forces on surfaces. Appl Environ Microbiol 2013; 80:637-43. [PMID: 24212582 DOI: 10.1128/aem.02745-13] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Adhesion of bacteria occurs on virtually all natural and synthetic surfaces and is crucial for their survival. Once they are adhering, bacteria start growing and form a biofilm, in which they are protected against environmental attacks. Bacterial adhesion to surfaces is mediated by a combination of different short- and long-range forces. Here we present a new atomic force microscopy (AFM)-based method to derive long-range bacterial adhesion forces from the dependence of bacterial adhesion forces on the loading force, as applied during the use of AFM. The long-range adhesion forces of wild-type Staphylococcus aureus parent strains (0.5 and 0.8 nN) amounted to only one-third of these forces measured for their more deformable isogenic Δpbp4 mutants that were deficient in peptidoglycan cross-linking. The measured long-range Lifshitz-Van der Waals adhesion forces matched those calculated from published Hamaker constants, provided that a 40% ellipsoidal deformation of the bacterial cell wall was assumed for the Δpbp4 mutants. Direct imaging of adhering staphylococci using the AFM peak force-quantitative nanomechanical property mapping imaging mode confirmed a height reduction due to deformation in the Δpbp4 mutants of 100 to 200 nm. Across naturally occurring bacterial strains, long-range forces do not vary to the extent observed here for the Δpbp4 mutants. Importantly, however, extrapolating from the results of this study, it can be concluded that long-range bacterial adhesion forces are determined not only by the composition and structure of the bacterial cell surface but also by a hitherto neglected, small deformation of the bacterial cell wall, facilitating an increase in contact area and, therewith, in adhesion force.
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Xu H, Murdaugh AE, Chen W, Aidala K, Ferguson MA, Spain EM, Núñez ME. Characterizing pilus-mediated adhesion of biofilm-forming E. coli to chemically diverse surfaces using atomic force microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:3000-11. [PMID: 23421314 PMCID: PMC3590879 DOI: 10.1021/la304745s] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Biofilms are complex communities of microorganisms living together at an interface. Because biofilms are often associated with contamination and infection, it is critical to understand how bacterial cells adhere to surfaces in the early stages of biofilm formation. Even harmless commensal Escherichia coli naturally forms biofilms in the human digestive tract by adhering to epithelial cells, a trait that presents major concerns in the case of pathogenic E. coli strains. The laboratory strain E. coli ZK1056 provides an intriguing model system for pathogenic E. coli strains because it forms biofilms robustly on a wide range of surfaces.E. coli ZK1056 cells spontaneously form living biofilms on polylysine-coated AFM cantilevers, allowing us to measure quantitatively by AFM the adhesion between native biofilm cells and substrates of our choice. We use these biofilm-covered cantilevers to probe E. coli ZK1056 adhesion to five substrates with distinct and well-characterized surface chemistries, including fluorinated, amine-terminated, and PEG-like monolayers, as well as unmodified silicon wafer and mica. Notably, after only 0-10 s of contact time, the biofilms adhere strongly to fluorinated and amine-terminated monolayers as well as to mica and weakly to "antifouling" PEG monolayers, despite the wide variation in hydrophobicity and charge of these substrates. In each case the AFM retraction curves display distinct adhesion profiles in terms of both force and distance, highlighting the cells' ability to adapt their adhesive properties to disparate surfaces. Specific inhibition of the pilus protein FimH by a nonhydrolyzable mannose analogue leads to diminished adhesion in all cases, demonstrating the critical role of type I pili in adhesion by this strain to surfaces bearing widely different functional groups. The strong and adaptable binding of FimH to diverse surfaces has unexpected implications for the design of antifouling surfaces and antiadhesion therapies.
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Affiliation(s)
- He Xu
- Department
of Chemistry and Department of Physics, Mount Holyoke College, South Hadley, Massachusetts 01075, United States
| | - Anne E. Murdaugh
- Department of Physics, Rollins
College, Winter Park, Florida 32789, United
States
| | - Wei Chen
- Department
of Chemistry and Department of Physics, Mount Holyoke College, South Hadley, Massachusetts 01075, United States
| | - Katherine
E. Aidala
- Department
of Chemistry and Department of Physics, Mount Holyoke College, South Hadley, Massachusetts 01075, United States
| | - Megan A. Ferguson
- Department of Chemistry, State University of New York, New Paltz, New York 12561,
United States
| | - Eileen M. Spain
- Department
of Chemistry, Occidental College, Los Angeles,
California 90041,
United States
| | - Megan E. Núñez
- Department
of Chemistry and Department of Physics, Mount Holyoke College, South Hadley, Massachusetts 01075, United States
- E-mail ; Ph (413) 538-2449; Fax (413) 538-2327
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Abstract
Viscoelastic deformation of the contact volume between adhering bacteria and substratum surfaces plays a role in their adhesion and detachment. Currently, there are no deformation models that account for the heterogeneous structure and composition of bacteria, consisting of a relatively soft outer layer and a more rigid, hard core enveloped by a cross-linked peptidoglycan layer. The aim of this paper is to present a new, simple model to derive the reduced Young’s modulus of the contact volume between adhering bacteria and substratum surfaces based on the relationship between deformation and applied external loading force, measured using atomic force microscopy. The model assumes that contact is established through a cylinder with constant volume and does not require assumptions on the properties and dimensions of the contact cylinder. The reduced Young’s moduli obtained (8 to 47 kPa) and dimensions of the contact cylinders could be interpreted on the basis of the cell surface features and cell wall characteristics, i.e., surfaces that are more rigid (because of either less fibrillation, less extracellular polymeric substance production, or a higher degree of cross-linking of the peptidoglycan layer) had shorter contact cylinders and higher reduced Young’s moduli. Application of an existing Hertz model to our experimental data yielded reduced Young’s moduli that were up to 100 times higher for all strains investigated, likely because the Hertz model pertains to a major extent to the more rigid peptidoglycan layer and not only to the soft outer bacterial cell surface, involved in the bond between a bacterium and a substratum surface. The viscoelastic properties of the bond between an adhering bacterium and a substratum surface play a role in determining bacterial detachment. For instance, removal of an oral biofilm proceeds according to a viscoelastic failure model, and biofilm left behind after toothbrushing has been found to possess expanded bond lengths between adhering bacteria due to viscoelastic deformation. Current elastic deformation models are unable to distinguish between the soft outer bacterial cell surface and the hard core of a bacterium, enveloped by a peptidoglycan layer. Therefore, here we present a simple model to calculate the Young’s modulus and deformation of the contact volume between an adhering bacterium and a substratum surface that accounts for the heterogeneous structure of a bacterium.
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Webster TJ, Patel AA, Rahaman MN, Sonny Bal B. Anti-infective and osteointegration properties of silicon nitride, poly(ether ether ketone), and titanium implants. Acta Biomater 2012; 8:4447-54. [PMID: 22863905 DOI: 10.1016/j.actbio.2012.07.038] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 07/19/2012] [Accepted: 07/25/2012] [Indexed: 11/17/2022]
Abstract
Silicon nitride (Si(3)N(4)) is an industrial ceramic used in spinal fusion and maxillofacial reconstruction. Maximizing bone formation and minimizing bacterial infection are desirable attributes in orthopedic implants designed to adhere to living bone. This study has compared these attributes of Si(3)N(4) implants with implants made from two other orthopedic biomaterials, i.e. poly(ether ether ketone) (PEEK) and titanium (Ti). Dense implants made of Si(3)N(4), PEEK, or Ti were surgically implanted into matching rat calvarial defects. Bacterial infection was induced with an injection of 1×10(4)Staphylococcus epidermidis. Control animals received saline only. On 3, 7, and 14days, and 3months post-surgery four rats per time period and material were killed, and calvariae were examined to quantify new bone formation and the presence or absence of bacteria. Quantitative evaluation of osteointegration to adjacent bone was done by measuring the resistance to implant push-out (n=8 rats each for Ti and PEEK, and n=16 rats for Si(3)N(4)). Three months after surgery in the absence of bacterial injection new bone formation around Si(3)N(4) was ∼69%, compared with 24% and 36% for PEEK and Ti, respectively. In the presence of bacteria new bone formation for Si(3)N(4), Ti, and PEEK was 41%, 26%, and 21%, respectively. Live bacteria were identified around PEEK (88%) and Ti (21%) implants, whereas none were present adjacent to Si(3)N(4). Push-out strength testing demonstrated statistically superior bone growth onto Si(3)N(4) compared with Ti and PEEK. Si(3)N(4) bioceramic implants demonstrated superior new bone formation and resistance to bacterial infection compared with Ti and PEEK.
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Affiliation(s)
- T J Webster
- School of Engineering and Department of Orthopaedics, Brown University, Providence, RI 02917, USA
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36
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An R, Yu Q, Zhang L, Zhu Y, Guo X, Fu S, Li L, Wang C, Wu X, Liu C, Lu X. Simple physical approach to reducing frictional and adhesive forces on a TiO2 surface via creating heterogeneous nanopores. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15270-15277. [PMID: 23046057 DOI: 10.1021/la3029325] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A simple physical strategy to reduce the frictional and adhesive forces on TiO(2) films was proposed by constructing mesoporous TiO(2) films with heterogeneously distributed nanopores on the film surfaces. In comparison, TiO(2) films with densely packed nanoparticles were also prepared. The crystal structure and morphology of the films were characterized with Raman spectroscopy, field emission scanning electron microscopy (FESEM), and atomic force microscopy (AFM). It was found that the TiO(2)(B) phase exists in the mesoporuos TiO(2) films but not in the densely packed films. The existence of TiO(2)(B) plays a significant role in creating and maintaining the nanopores in the mesoporous TiO(2) films. The frictional and adhesive forces were measured on both films using AFM. The mesoporous films exhibit two typical adhesion forces of around 3 and 12 nN in the force distribution profile whereas the densely packed films show only one around 12 nN. The frictional coefficients were 2.6 × 10(-3) and 6.7 × 10(-2) for the mesoporous and densely packed TiO(2) films, respectively. A model based on the atomic structures of a thin film of water molecules adsorbed on TiO(2) surfaces leading to hydrophobic effects was proposed to understand the lower frictional and adhesive forces observed on the mesoporous TiO(2) films. This simple physical approach to reducing the frictional and adhesive forces on TiO(2) films could have broad applications to a variety of surface coatings.
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Affiliation(s)
- Rong An
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, 5 Xinmofan Road, Nanjing 210009, PR China
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Zhang J, Parlak Z, Bowers CM, Oas T, Zauscher S. Mapping mechanical properties of organic thin films by force-modulation microscopy in aqueous media. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2012; 3:464-474. [PMID: 23019540 PMCID: PMC3458590 DOI: 10.3762/bjnano.3.53] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 05/31/2012] [Indexed: 06/01/2023]
Abstract
The mechanical properties of organic and biomolecular thin films on surfaces play an important role in a broad range of applications. Although force-modulation microscopy (FMM) is used to map the apparent elastic properties of such films with high lateral resolution in air, it has rarely been applied in aqueous media. In this letter we describe the use of FMM to map the apparent elastic properties of self-assembled monolayers and end-tethered protein thin films in aqueous media. Furthermore, we describe a simple analysis of the contact mechanics that enables the selection of FMM imaging parameters and thus yields a reliable interpretation of the FMM image contrast.
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Affiliation(s)
- Jianming Zhang
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
- Center for Biologically Inspired Materials and Materials Systems, Duke University, Durham, North Carolina 27708, USA
| | - Zehra Parlak
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
- Center for Biologically Inspired Materials and Materials Systems, Duke University, Durham, North Carolina 27708, USA
- Department of Biochemistry, Box 3711, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Carleen M Bowers
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Terrence Oas
- Department of Biochemistry, Box 3711, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Stefan Zauscher
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
- Center for Biologically Inspired Materials and Materials Systems, Duke University, Durham, North Carolina 27708, USA
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Quilès F, Polyakov P, Humbert F, Francius G. Production of extracellular glycogen by Pseudomonas fluorescens: spectroscopic evidence and conformational analysis by biomolecular recognition. Biomacromolecules 2012; 13:2118-27. [PMID: 22686500 DOI: 10.1021/bm300497c] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Glycogen is mainly found as the principal storage form of glucose in cells. Many bacteria are able to synthesize large amounts of glycogen under unfavorable life conditions. By combining infrared spectroscopy, single molecule force spectroscopy (SMFS) and immuno-staining technique, we evidenced that planktonic P. fluorescens (Pf) cells are also able to produce glycogen as an extracellular polymeric substance. For this purpose, Pf suspensions were examined at 3 and 21 h of growth in nutritive medium (LB, 0.5 g/L). The conformation of the extracellular glycogen, revealed through its infrared spectral signature, has been investigated by SMFS measurements using Freely Jointed Chain model. The analysis of force versus distance curves showed over growth time that the increase of glycogen production was accompanied by an increase in glycogen contour lengths and ramifications. These results demonstrated that the production of extracellular bacterial glycogen can occur even if the cells are not subjected to unfavorable life conditions.
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Affiliation(s)
- Fabienne Quilès
- Université de Lorraine, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, LCPME, UMR 7564, Villers-lès-Nancy, France.
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40
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Arnal L, Serra DO, Cattelan N, Castez MF, Vázquez L, Salvarezza RC, Yantorno OM, Vela ME. Adhesin contribution to nanomechanical properties of the virulent Bordetella pertussis envelope. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:7461-7469. [PMID: 22515332 DOI: 10.1021/la300811m] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Adherence to a biological surface allows bacteria to colonize and persist within the host and represents an essential first step in the pathogenesis of most bacterial diseases. Consequently, the physicochemical properties of the outer membrane in bacteria play a key role for attachment to surfaces and therefore for biofilm formation. Bordetella pertussis is a Gram-negative bacterium that colonizes the respiratory tract of humans, producing whooping cough or pertussis, a highly infectious disease. B. pertussis uses various adhesins exposed on its surface to promote cell-surface and cell-cell interactions. The most dominant adhesin function is displayed by filamentous hemagglutinin (FHA). B. pertussis Tohama I wild-type (Vir+) strain and two defective mutants, an avirulent (Vir-) and a FHA-deficient (FHA-) B. pertussis strains were studied by AFM under physiological conditions to evaluate how the presence or absence of adhesins affects the mechanical properties of the B. pertussis cell surface. Quantitative information on the nanomechanical properties of the bacterial envelope was obtained by AFM force-volume analysis. These studies suggested that the presence of virulence factors is correlated with an increase in the average membrane rigidity, which is largely influenced by the presence of FHA. Moreover, for this system we built a nanoscale stiffness map that reveals an inhomogeneous spatial distribution of Young modulus as well as the presence of rigid nanodomains on the cell surface.
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Affiliation(s)
- L Arnal
- Facultad de Ciencias Exactas, Centro de Investigación y Desarrollo de Fermentaciones Industriales (CINDEFI-CONICET-CCT La Plata), UNLP. 50 No. 227, 1900 La Plata, Argentina
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Krapf MEM, Lartiges BS, Merlin C, Francius G, Ghanbaja J, Duval JFL. Polyethyleneimine-mediated flocculation of Shewanella oneidensis MR-1: impacts of cell surface appendage and polymer concentration. WATER RESEARCH 2012; 46:1838-1846. [PMID: 22285041 DOI: 10.1016/j.watres.2011.12.061] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Revised: 12/22/2011] [Accepted: 12/30/2011] [Indexed: 05/31/2023]
Abstract
In wastewater treatment plants, optimizing bacterial flocculation and bacterial sludge dewatering requires a detailed understanding of the concomitant biological and physico-chemical processes governing the action of flocculating agent on living cells. Here we investigate the interactions between polyethyleneimine (PEI, 60,000g/mol) and Shewanella oneidensis MR-1 lacking or not the lipopolysaccharide (LPS) O-antigen surface structure. Flocculation tests were performed on bacteria with/without LPS O-antigen after being exposed to 0-100mg/L PEI concentrations. Measurements of electrophoretic mobility and bacterial aggregates size were complemented by transmission electron micrographs and atomic force microscopy images. While low PEI concentrations (<20mg/L) lead to flocculation of both bare and LPS O-antigen-decorated bacterial strains, the lysis of bacterial membranes occurred at larger polymer concentrations for the latter, which highlights the protective role of LPS O-antigen against harmful PEI-mediated membrane alterations. Depending on polymer concentration, two types of bacterial aggregates are identified: one that solely integrates bacterial cells, and another that includes both cells and cell residues resulting from lysis (membrane and/or LPS fragments, and inner cell content materials). The latter is expected to significantly contribute to water entrapping in sludge and thus lower dewatering process efficiency.
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Affiliation(s)
- Marie-Eve M Krapf
- Laboratoire Environnement et Minéralurgie, Nancy Université, CNRS UMR7569, B.P. 40, F-54501 Vandoeuvre-lès-Nancy, France.
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42
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Measurement of bacterial volume by transmission-through-dye imaging. J Microbiol Methods 2011; 87:375-7. [DOI: 10.1016/j.mimet.2011.08.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 08/26/2011] [Accepted: 08/26/2011] [Indexed: 11/22/2022]
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Francius G, Polyakov P, Merlin J, Abe Y, Ghigo JM, Merlin C, Beloin C, Duval JFL. Bacterial surface appendages strongly impact nanomechanical and electrokinetic properties of Escherichia coli cells subjected to osmotic stress. PLoS One 2011; 6:e20066. [PMID: 21655293 PMCID: PMC3105017 DOI: 10.1371/journal.pone.0020066] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 04/17/2011] [Indexed: 11/19/2022] Open
Abstract
The physicochemical properties and dynamics of bacterial envelope, play a major role in bacterial activity. In this study, the morphological, nanomechanical and electrohydrodynamic properties of Escherichia coli K-12 mutant cells were thoroughly investigated as a function of bulk medium ionic strength using atomic force microscopy (AFM) and electrokinetics (electrophoresis). Bacteria were differing according to genetic alterations controlling the production of different surface appendages (short and rigid Ag43 adhesins, longer and more flexible type 1 fimbriae and F pilus). From the analysis of the spatially resolved force curves, it is shown that cells elasticity and turgor pressure are not only depending on bulk salt concentration but also on the presence/absence and nature of surface appendage. In 1 mM KNO(3), cells without appendages or cells surrounded by Ag43 exhibit large Young moduli and turgor pressures (∼700-900 kPa and ∼100-300 kPa respectively). Under similar ionic strength condition, a dramatic ∼50% to ∼70% decrease of these nanomechanical parameters was evidenced for cells with appendages. Qualitatively, such dependence of nanomechanical behavior on surface organization remains when increasing medium salt content to 100 mM, even though, quantitatively, differences are marked to a much smaller extent. Additionally, for a given surface appendage, the magnitude of the nanomechanical parameters decreases significantly when increasing bulk salt concentration. This effect is ascribed to a bacterial exoosmotic water loss resulting in a combined contraction of bacterial cytoplasm together with an electrostatically-driven shrinkage of the surface appendages. The former process is demonstrated upon AFM analysis, while the latter, inaccessible upon AFM imaging, is inferred from electrophoretic data interpreted according to advanced soft particle electrokinetic theory. Altogether, AFM and electrokinetic results clearly demonstrate the intimate relationship between structure/flexibility and charge of bacterial envelope and propensity of bacterium and surface appendages to contract under hypertonic conditions.
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Affiliation(s)
- Grégory Francius
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, Nancy Université, CNRS UMR7564, Villers-lès-Nancy, France
| | - Pavel Polyakov
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, Nancy Université, CNRS UMR7564, Villers-lès-Nancy, France
| | - Jenny Merlin
- Laboratoire Environnement et Minéralurgie, Nancy Université, CNRS UMR7569, Vandoeuvre-lès-Nancy, France
| | - Yumiko Abe
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, Nancy Université, CNRS UMR7564, Villers-lès-Nancy, France
| | - Jean-Marc Ghigo
- Institut Pasteur, Unité de Génétique des Biofilms, Paris, France
- CNRS URA 2172, Paris, France
| | - Christophe Merlin
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, Nancy Université, CNRS UMR7564, Villers-lès-Nancy, France
| | - Christophe Beloin
- Institut Pasteur, Unité de Génétique des Biofilms, Paris, France
- CNRS URA 2172, Paris, France
| | - Jérôme F. L. Duval
- Laboratoire Environnement et Minéralurgie, Nancy Université, CNRS UMR7569, Vandoeuvre-lès-Nancy, France
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Polyakov P, Soussen C, Duan J, Duval JFL, Brie D, Francius G. Automated force volume image processing for biological samples. PLoS One 2011; 6:e18887. [PMID: 21559483 PMCID: PMC3084721 DOI: 10.1371/journal.pone.0018887] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 03/24/2011] [Indexed: 01/09/2023] Open
Abstract
Atomic force microscopy (AFM) has now become a powerful technique for investigating on a molecular level, surface forces, nanomechanical properties of deformable particles, biomolecular interactions, kinetics, and dynamic processes. This paper specifically focuses on the analysis of AFM force curves collected on biological systems, in particular, bacteria. The goal is to provide fully automated tools to achieve theoretical interpretation of force curves on the basis of adequate, available physical models. In this respect, we propose two algorithms, one for the processing of approach force curves and another for the quantitative analysis of retraction force curves. In the former, electrostatic interactions prior to contact between AFM probe and bacterium are accounted for and mechanical interactions operating after contact are described in terms of Hertz-Hooke formalism. Retraction force curves are analyzed on the basis of the Freely Jointed Chain model. For both algorithms, the quantitative reconstruction of force curves is based on the robust detection of critical points (jumps, changes of slope or changes of curvature) which mark the transitions between the various relevant interactions taking place between the AFM tip and the studied sample during approach and retraction. Once the key regions of separation distance and indentation are detected, the physical parameters describing the relevant interactions operating in these regions are extracted making use of regression procedure for fitting experiments to theory. The flexibility, accuracy and strength of the algorithms are illustrated with the processing of two force-volume images, which collect a large set of approach and retraction curves measured on a single biological surface. For each force-volume image, several maps are generated, representing the spatial distribution of the searched physical parameters as estimated for each pixel of the force-volume image.
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Affiliation(s)
- Pavel Polyakov
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, LCPME, UMR 7564, Nancy-Université, CNRS, Vandoeuvre lès Nancy, France
| | - Charles Soussen
- Centre de Recherche en Automatique de Nancy, CRAN, UMR 7039, Nancy-Université, CNRS, Vandoeuvre lès Nancy, France
| | - Junbo Duan
- Centre de Recherche en Automatique de Nancy, CRAN, UMR 7039, Nancy-Université, CNRS, Vandoeuvre lès Nancy, France
| | - Jérôme F. L. Duval
- Laboratoire Environnement et Minéralurgie, LEM, UMR 7569, Nancy-Université, CNRS, Vandoeuvre lès Nancy, France
| | - David Brie
- Centre de Recherche en Automatique de Nancy, CRAN, UMR 7039, Nancy-Université, CNRS, Vandoeuvre lès Nancy, France
- * E-mail: (GF); (DB)
| | - Grégory Francius
- Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, LCPME, UMR 7564, Nancy-Université, CNRS, Vandoeuvre lès Nancy, France
- * E-mail: (GF); (DB)
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Lecuyer S, Rusconi R, Shen Y, Forsyth A, Vlamakis H, Kolter R, Stone HA. Shear stress increases the residence time of adhesion of Pseudomonas aeruginosa. Biophys J 2011; 100:341-50. [PMID: 21244830 DOI: 10.1016/j.bpj.2010.11.078] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 11/09/2010] [Accepted: 11/30/2010] [Indexed: 11/18/2022] Open
Abstract
Although ubiquitous, the processes by which bacteria colonize surfaces remain poorly understood. Here we report results for the influence of the wall shear stress on the early-stage adhesion of Pseudomonas aeruginosa PA14 on glass and polydimethylsiloxane surfaces. We use image analysis to measure the residence time of each adhering bacterium under flow. Our main finding is that, on either surface, the characteristic residence time of bacteria increases approximately linearly as the shear stress increases (∼0-3.5 Pa). To investigate this phenomenon, we used mutant strains defective in surface organelles (type I pili, type IV pili, or the flagellum) or extracellular matrix production. Our results show that, although these bacterial surface features influence the frequency of adhesion events and the early-stage detachment probability, none of them is responsible for the trend in the shear-enhanced adhesion time. These observations bring what we believe are new insights into the mechanism of bacterial attachment in shear flows, and suggest a role for other intrinsic features of the cell surface, or a dynamic cell response to shear stress.
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46
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Study of the time effect on the strength of cell-cell adhesion force by a novel nano-picker. Biochem Biophys Res Commun 2011; 409:160-5. [PMID: 21510921 DOI: 10.1016/j.bbrc.2011.04.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2011] [Accepted: 04/05/2011] [Indexed: 11/21/2022]
Abstract
Cell's adhesion is important to cell's interaction and activates. In this paper, a novel method for cell-cell adhesion force measurement was proposed by using a nano-picker. The effect of the contact time on the cell-cell adhesion force was studied. The nano-picker was fabricated from an atomic force microscopy (AFM) cantilever by nano fabrication technique. The cell-cell adhesion force was measured based on the deflection of the nano-picker beam. The result suggests that the adhesion force between cells increased with the increasing of contact time at the first few minutes. After that, the force became constant. This measurement methodology was based on the nanorobotic manipulation system inside an environmental scanning electron microscope. It can realize both the observation and manipulation of a single cell at nanoscale. The quantitative and precise cell-cell adhesion force result can be obtained by this method. It would help us to understand the single cell interaction with time and would benefit the research in medical and biological fields potentially.
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Hu Y, Ulstrup J, Zhang J, Molin S, Dupres V. Adhesive properties of Staphylococcus epidermidis probed by atomic force microscopy. Phys Chem Chem Phys 2011; 13:9995-10003. [PMID: 21350761 DOI: 10.1039/c0cp02800b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mapping of the surface properties of Staphylococcus epidermidis and of biofilm forming bacteria in general is a key to understand their functions, particularly their adhesive properties. To gain a comprehensive view of the structural and chemical properties of S. epidermidis, four different strains (biofilm positive and biofilm negative strains) were analyzed using in situ atomic force microscopy (AFM). Force measurements performed using bare hydrophilic silicon nitride tips disclosed similar adhesive properties for each strain. However, use of hydrophobic tips showed that hydrophobic forces are not the driving forces for adhesion of the four strains. Rather, the observation of sawtooth force-distance patterns on the surface of biofilm positive strains documents the presence of modular proteins such as Aap that may mediate cell adhesion. Treatment of two biofilm positive strains with two chemical inhibitor compounds leads to a loss of adhesion, suggesting that AFM could be a valuable tool to screen for anti-adhesion molecules.
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Affiliation(s)
- Yifan Hu
- Department of Chemistry, DTU Chemistry, Building 207, Technical University of Denmark, DK-2800 Lyngby, Denmark
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48
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Zhang W, Stack AG, Chen Y. Interaction force measurement between E. coli cells and nanoparticles immobilized surfaces by using AFM. Colloids Surf B Biointerfaces 2011; 82:316-24. [DOI: 10.1016/j.colsurfb.2010.09.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 09/02/2010] [Accepted: 09/02/2010] [Indexed: 11/26/2022]
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49
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Lower SK, Yongsunthon R, Casillas-Ituarte NN, Taylor ES, DiBartola AC, Lower BH, Beveridge TJ, Buck AW, Fowler VG. A tactile response in Staphylococcus aureus. Biophys J 2011; 99:2803-11. [PMID: 21044577 DOI: 10.1016/j.bpj.2010.08.063] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2010] [Revised: 07/16/2010] [Accepted: 08/30/2010] [Indexed: 01/22/2023] Open
Abstract
It is well established that bacteria are able to respond to temporal gradients (e.g., by chemotaxis). However, it is widely held that prokaryotes are too small to sense spatial gradients. This contradicts the common observation that the vast majority of bacteria live on the surface of a solid substrate (e.g., as a biofilm). Herein we report direct experimental evidence that the nonmotile bacterium Staphylococcus aureus possesses a tactile response, or primitive sense of touch, that allows it to respond to spatial gradients. Attached cells recognize their substrate interface and localize adhesins toward that region. Braille-like avidity maps reflect a cell's biochemical sensory response and reveal ultrastructural regions defined by the actual binding activity of specific proteins.
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50
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Busscher HJ, Norde W, Sharma PK, van der Mei HC. Interfacial re-arrangement in initial microbial adhesion to surfaces. Curr Opin Colloid Interface Sci 2010. [DOI: 10.1016/j.cocis.2010.05.014] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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