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Khandelwal P, Singh DK, Poddar P. Advances in the Experimental and Theoretical Understandings of Antibiotic Conjugated Gold Nanoparticles for Antibacterial Applications. ChemistrySelect 2019. [DOI: 10.1002/slct.201900083] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Puneet Khandelwal
- Physical & Materials Chemistry DivisionCSIR-National Chemical Laboratory Pune - 411008 India
| | - Dheeraj K. Singh
- Department of PhysicsInstitute of Infrastructure Technology Research & Management Ahmedabad - 380026 India
| | - Pankaj Poddar
- Physical & Materials Chemistry DivisionCSIR-National Chemical Laboratory Pune - 411008 India
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2
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Uzoechi SC, Abu-Lail NI. Changes in Cellular Elasticities and Conformational Properties of Bacterial Surface Biopolymers of Multidrug-Resistant Escherichia coli (MDR- E. coli) Strains in Response to Ampicillin. ACTA ACUST UNITED AC 2019; 5. [PMID: 31179402 PMCID: PMC6550352 DOI: 10.1016/j.tcsw.2019.100019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The roles of the thicknesses and grafting densities of the surface biopolymers of four multi-drug resistant (MDR) Escherichia coli bacterial strains that varied in their biofilm formation in controlling cellular elasticities after exposure to ampicillin were investigated using atomic force microscopy. Exposure to ampicillin was carried out at minimum inhibitory concentrations for different duration times. Our results indicated that the four strains resisted ampicillin through variable mechanisms. Strain A5 did not change its cellular properties upon exposure to ampicillin and as such resisted ampicillin through dormancy. Strain H5 increased its biopolymer brush thickness, adhesion and biofilm formation and kept its roughness, surface area and cell elasticity unchanged upon exposure to ampicillin. As such, this strain likely limits the diffusion of ampicillin by forming strong biofilms. At three hours’ exposure to ampicillin, strains D4 and A9 increased their roughness, surface areas, biofilm formation, and brush thicknesses and decreased their elasticities. Therefore, at short exposure times to ampicillin, these strains resisted ampicillin through forming strong biofilms that impede ampicillin diffusion. At eight hours’ exposure to ampicillin, strains D4 and A9 collapsed their biopolymers, increased their apparent grafting densities and increased their cellular elasticities. Therefore, at long exposure times to ampicillin, cells utilized their higher rigidity to reduce the diffusion of ampicillin into the cells. The findings of this study clearly point to the potential of using the nanoscale characterization of MDR bacterial properties as a means to monitor cell modifications that enhance “phenotypic antibiotic resistance”.
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Affiliation(s)
- Samuel C Uzoechi
- Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164.,Department of Biomedical Technology, Federal University of Technology, Owerri, PMB 1526, Owerri, Nigeria
| | - Nehal I Abu-Lail
- Department of Biomedical Engineering, The University of Texas at San Antonio, San Antonio, TX, 78249
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3
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Uzoechi SC, Abu-Lail NI. The Effects of β-Lactam Antibiotics on Surface Modifications of Multidrug-Resistant Escherichia coli: A Multiscale Approach. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2019; 25:135-150. [PMID: 30869575 PMCID: PMC6599534 DOI: 10.1017/s1431927618015696] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Possible multidrug-resistant (MDR) mechanisms of four resistant strains of Escherichia coli to a model β-lactam, ampicillin, were investigated using contact angle measurements of wettability, crystal violet assays of permeability, biofilm formation, fluorescence imaging, and nanoscale analyses of dimensions, adherence, and roughness. Upon exposure to ampicillin, one of the resistant strains, E. coli A5, changed its phenotype from elliptical to spherical, maintained its roughness and biofilm formation abilities, decreased its length and surface area, maintained its cell wall integrity, increased its hydrophobicity, and decreased its nanoscale adhesion to a model surface of silicon nitride. Such modifications are suggested to allow these cells to conserve energy during metabolic dormancy. In comparison, resistant strains E. coli D4, A9, and H5 elongated their cells, increased their roughness, increased their nanoscale adhesion forces, became more hydrophilic, and increased their biofilm formation upon exposure to ampicillin. These results suggest that these strains resisted ampicillin through biofilm formation that possibly introduces diffusion limitations to antibiotics. Investigations of how MDR bacterial cells modify their surfaces in response to antibiotics can guide research efforts aimed at designing more effective antibiotics and new treatment strategies for MDR bacterial infections.
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Affiliation(s)
- Samuel C. Uzoechi
- Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164, USA
| | - Nehal I. Abu-Lail
- Department of Biomedical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, USA
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Bhat SV, Kamencic B, Körnig A, Shahina Z, Dahms TES. Exposure to Sub-lethal 2,4-Dichlorophenoxyacetic Acid Arrests Cell Division and Alters Cell Surface Properties in Escherichia coli. Front Microbiol 2018; 9:44. [PMID: 29472899 PMCID: PMC5810288 DOI: 10.3389/fmicb.2018.00044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 01/09/2018] [Indexed: 11/13/2022] Open
Abstract
Escherichia coli is a robust, easily adaptable and culturable bacterium in vitro, and a model bacterium for studying the impact of xenobiotics in the environment. We have used correlative atomic force – laser scanning confocal microscopy (AFM-LSCM) to characterize the mechanisms of cellular response to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). One of the most extensively used herbicides world-wide, 2,4-D is known to cause hazardous effects in diverse non-target organisms. Sub-lethal concentrations of 2,4-D caused DNA damage in E. coli WM1074 during short exposure periods which increased significantly over time. In response to 2,4-D, FtsZ and FtsA relocalized within seconds, coinciding with the complete inhibition of cell septation and cell elongation. Exposure to 2,4-D also resulted in increased activation of the SOS response. Changes to cell division were accompanied by concomitant changes to surface roughness, elasticity and adhesion in a time-dependent manner. This is the first study describing the mechanistic details of 2,4-D at sub-lethal levels in bacteria. Our study suggests that 2,4-D arrests E. coli cell division within seconds after exposure by disrupting the divisome complex, facilitated by dissipation of membrane potential. Over longer exposures, 2,4-D causes filamentation as a result of an SOS response to oxidative stress induced DNA damage.
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Affiliation(s)
- Supriya V Bhat
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | - Belma Kamencic
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | | | - Zinnat Shahina
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | - Tanya E S Dahms
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
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Fernández MV, Agüero MV, Jagus RJ. Green tea extract: A natural antimicrobial with great potential for controlling native microbiota,
Listeria innocua
and
Escherichia coli
in fresh‐cut beet leaves. J Food Saf 2017. [DOI: 10.1111/jfs.12374] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- María Verónica Fernández
- Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científica y Técnicas (CONICET), Instituto de Tecnologías y Ciencias de la Ingeniería (INTECIN), Facultad de IngenieríaBuenos Aires Argentina
- Departamento de Ingeniería Química, Laboratorio de Microbiología Industrial: Tecnología de alimentosBuenos Aires Argentina
- Peruilh Foundation, Facultad de Ingeniería, Universidad de Buenos AiresBuenos Aires Argentina
| | - María Victoria Agüero
- Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científica y Técnicas (CONICET), Instituto de Tecnologías y Ciencias de la Ingeniería (INTECIN), Facultad de IngenieríaBuenos Aires Argentina
- Departamento de Ingeniería Química, Laboratorio de Microbiología Industrial: Tecnología de alimentosBuenos Aires Argentina
| | - Rosa Juana Jagus
- Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científica y Técnicas (CONICET), Instituto de Tecnologías y Ciencias de la Ingeniería (INTECIN), Facultad de IngenieríaBuenos Aires Argentina
- Departamento de Ingeniería Química, Laboratorio de Microbiología Industrial: Tecnología de alimentosBuenos Aires Argentina
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6
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Probing the threshold of membrane damage and cytotoxicity effects induced by silica nanoparticles in Escherichia coli bacteria. Adv Colloid Interface Sci 2017; 245:81-91. [PMID: 28477864 DOI: 10.1016/j.cis.2017.04.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/21/2017] [Accepted: 04/21/2017] [Indexed: 10/19/2022]
Abstract
The engineering of nanomaterials, because of their specific properties, is increasingly being developed for commercial purposes over the past decades, to enhance diagnosis, cosmetics properties as well as sensing efficiency. However, the understanding of their fate and thus their interactions at the cellular level with bio-organisms remains elusive. Here, we investigate the size- and charge-dependence of the damages induced by silica nanoparticles (SiO2-NPs) on Gram-negative Escherichia coli bacteria. We show and quantify the existence of a NPs size threshold discriminating toxic and inert SiO2-NPs with a critical particle diameter (Φc) in the range 50nm-80nm. This particular threshold is identified at both the micrometer scale via viability tests through Colony Forming Units (CFU) counting, and the nanometer scale via atomic force microscopy (AFM). At this nanometer scale, AFM emphasizes the interaction between the cell membrane and SiO2-NPs from both topographic and mechanical points of view. For SiO2-NPs with Φ>Φc no change in E. coli morphology nor its outer membrane (OM) organization is observed unless the NPs are positively charged in which case reorganization and disruption of the OM are detected. Conversely, when Φ<Φc, E. coli exhibit unusual spherical shapes, partial collapse, even lysis, and OM reorganization.
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Wang M, Wang Z, Li S, Wang Z, Zhao J. Mediated electrochemical method for the analysis of membrane damage effects of phenolic compounds to Staphylococcus aureus. J Electroanal Chem (Lausanne) 2015. [DOI: 10.1016/j.jelechem.2015.09.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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8
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Lamprecht C, Hinterdorfer P, Ebner A. Applications of biosensing atomic force microscopy in monitoring drug and nanoparticle delivery. Expert Opin Drug Deliv 2014; 11:1237-53. [PMID: 24809228 DOI: 10.1517/17425247.2014.917078] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION The therapeutic effects of medicinal drugs not only depend on their properties, but also on effective transport to the target receptor. Here we highlight recent developments in this discipline and show applications of atomic force microscopy (AFM) that enable us to track the effects of drugs and the effectiveness of nanoparticle delivery at the single molecule level. AREAS COVERED Physiological AFM imaging enables visualization of topographical changes to cells as a result of drug exposure and allows observation of cellular responses that yield morphological changes. When we upgrade the regular measuring tip to a molecular biosensor, it enables investigation of functional changes at the molecular level via single molecule force spectroscopy. EXPERT OPINION Biosensing AFM techniques have generated powerful tools to monitor drug delivery in (living) cells. While technical developments in actual AFM methods have simplified measurements at relevant physiological conditions, understanding both the biological and technical background is still a crucial factor. However, due to its potential impact, we expect the number of application-based biosensing AFM techniques to further increase in the near future.
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Affiliation(s)
- Constanze Lamprecht
- University of Kiel, Institute of Materials Science Biocompatible Nanomaterials , Kaiserstr.2, 24143 Kiel , Germany
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9
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Longo G, Kasas S. Effects of antibacterial agents and drugs monitored by atomic force microscopy. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2014; 6:230-44. [PMID: 24616433 DOI: 10.1002/wnan.1258] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 01/06/2014] [Accepted: 01/13/2014] [Indexed: 11/07/2022]
Abstract
Originally invented for topographic imaging, atomic force microscopy (AFM) has evolved into a multifunctional biological toolkit, enabling to measure structural and functional details of cells and molecules. Its versatility and the large scope of information it can yield make it an invaluable tool in any biologically oriented laboratory, where researchers need to perform characterizations of living samples as well as single molecules in quasi-physiological conditions and with nanoscale resolution. In the last 20 years, AFM has revolutionized the characterization of microbial cells by allowing a better understanding of their cell wall and of the mechanism of action of drugs and by becoming itself a powerful diagnostic tool to study bacteria. Indeed, AFM is much more than a high-resolution microscopy technique. It can reconstruct force maps that can be used to explore the nanomechanical properties of microorganisms and probe at the same time the morphological and mechanical modifications induced by external stimuli. Furthermore it can be used to map chemical species or specific receptors with nanometric resolution directly on the membranes of living organisms. In summary, AFM offers new capabilities and a more in-depth insight in the structure and mechanics of biological specimens with an unrivaled spatial and force resolution. Its application to the study of bacteria is extremely significant since it has already delivered important information on the metabolism of these small microorganisms and, through new and exciting technical developments, will shed more light on the real-time interaction of antimicrobial agents and bacteria.
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Affiliation(s)
- Giovanni Longo
- Ecole Polytechnique Fédérale de Lausanne, LPMV, Lausanne, Switzerland; Istituto Superiore di Sanità, Rome, Italy
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10
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Chang KC, Chiang YW, Yang CH, Liou JW. Atomic force microscopy in biology and biomedicine. Tzu Chi Med J 2012. [DOI: 10.1016/j.tcmj.2012.08.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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11
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Cui Y, Kim SH, Kim H, Yeom J, Ko K, Park W, Park S. AFM probing the mechanism of synergistic effects of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) with cefotaxime against extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. PLoS One 2012; 7:e48880. [PMID: 23152812 PMCID: PMC3496731 DOI: 10.1371/journal.pone.0048880] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 10/01/2012] [Indexed: 11/26/2022] Open
Abstract
Background Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae poses serious challenges to clinicians because of its resistance to many classes of antibiotics. Methods and Findings The mechanism of synergistic activity of a combination of (−)-epigallocatechin-3-gallate (EGCG) and β-lactam antibiotics cefotaxime was studied on Extended-spectrum β-lactamase producing Escherichia coli (ESBL-EC), by visualizing the morphological alteration on the cell wall induced by the combination using atomic force microscopy (AFM). Cells at sub-MICs (sub-minimum inhibitory concentrations) of cefotaxime were initially filamentated but recovered to the normal shape later, whereas cells at sub-MICs of EGCG experienced temporal disturbance on the cell wall such as leakage and release of cellular debris and groove formation, but later recovered to the normal shape. In contrast, the combination of cefotaxime and EGCG at their respective sub-MICs induced permanent cellular damages as well as continuous elongation in cells and eventually killed them. Flow cytometry showed that intracellular oxidative stress levels in the cell treated with a combination of EGCG and cefotaxime at sub-MICs were higher than those in the cells treated with either cefotaxime or EGCG at sub-MICs. Conclusions These results suggest that the synergistic effect of EGCG between EGCG and cefotaxime against ESBL-EC is related to cooperative activity of exogenous and endogenous reactive oxygen species (ROS) generated by EGCG and cefotaxime, respectively.
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Affiliation(s)
- Yidan Cui
- Department of Chemistry and Nano Sciences, Ewha Womans University, Seoul, Korea
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | - So Hyun Kim
- Department of Chemistry and Nano Sciences, Ewha Womans University, Seoul, Korea
| | - Hyunseok Kim
- Department of Chemistry and Nano Sciences, Ewha Womans University, Seoul, Korea
| | - Jinki Yeom
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Korea
| | - Kisung Ko
- Department of Medicine, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Woojun Park
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Korea
| | - Sungsu Park
- Department of Chemistry and Nano Sciences, Ewha Womans University, Seoul, Korea
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
- * E-mail:
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Abstract
Unraveling the structure of microbial cells is a major challenge in current microbiology and offers exciting prospects in biomedicine. Atomic force microscopy (AFM) appears as a powerful method to image the surface ultrastructure of live cells under physiological conditions and allows real-time imaging to follow dynamic processes such as cell growth, and division and effects of drugs and chemicals. The following chapter introduces different methods of sample preparation to gain insights into the microbial cell organization. Successful strategies to immobilize microorganisms, including physical entrapment and chemical attachment, are described. This step is a key step and a prerequisite of any analysis and persists as an important limitation to the application of AFM to microbiology due to the wide diversity of microorganisms. Finally, some applications are depicted which underlie the ability of AFM to explore living microbes with unprecedented resolution.
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13
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Cui Y, Oh YJ, Lim J, Youn M, Lee I, Pak HK, Park W, Jo W, Park S. AFM study of the differential inhibitory effects of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) against Gram-positive and Gram-negative bacteria. Food Microbiol 2011; 29:80-7. [PMID: 22029921 DOI: 10.1016/j.fm.2011.08.019] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 08/22/2011] [Accepted: 08/25/2011] [Indexed: 11/19/2022]
Abstract
(-)-Epigallocatechin-3-gallate (EGCG), a main constituent of tea catechins, affects Gram-positive and Gram-negative bacteria differently; however, the underlying mechanisms are not clearly understood. Atomic force microscopy (AFM) was used to compare morphological alterations in Gram-positive and Gram-negative bacteria induced by EGCG and by H(2)O(2) at sub-minimum inhibitory concentrations (MICs). EGCG initially induced aggregates in the cell envelopes of Staphylococcus aureus and eventually caused cell lysis, which was not observed in cells treated with H(2)O(2). It initially induced nanoscale perforations or microscale grooves in the cell envelopes of Escherichia coli O157:H7 which eventually disappeared, similar to E. coli cells treated with H(2)O(2). An E. coli O157:H7 tpx mutant, with a defect in thioredoxin-dependent thiol peroxidase (Tpx), was more severely damaged by EGCG when compared with its wild type. Similar differing effects were observed in other Gram-positive and Gram-negative bacteria when exposed to EGCG; it caused aggregated in Streptococcus mutans, while it caused grooves in Pseudomonas aeruginosa. AFM results suggest that the major morphological changes of Gram-negative bacterial cell walls induced by EGCG depend on H(2)O(2) release. This is not the case for Gram-positive bacteria. Oxidative stress in Gram-negative bacteria induced by EGCG was confirmed by flow cytometry.
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Affiliation(s)
- Y Cui
- Department of Chemistry and Nano Sciences, Ewha Womans University, Seoul, Republic of Korea
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Müller DJ, Dufrêne YF. Atomic force microscopy: a nanoscopic window on the cell surface. Trends Cell Biol 2011; 21:461-9. [PMID: 21664134 DOI: 10.1016/j.tcb.2011.04.008] [Citation(s) in RCA: 231] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 04/22/2011] [Accepted: 04/27/2011] [Indexed: 12/14/2022]
Abstract
Atomic force microscopy (AFM) techniques provide a versatile platform for imaging and manipulating living cells to single-molecule resolution, thereby enabling us to address pertinent questions in key areas of cell biology, including cell adhesion and signalling, embryonic and tissue development, cell division and shape, and microbial pathogenesis. In this review, we describe the principles of AFM, and survey recent breakthroughs made in AFM-based cell nanoscopy, showing how the technology has increased our molecular understanding of the organization, mechanics, interactions and processes of the cell surface. We also discuss the advantages and limitations of AFM techniques, and the challenges remaining to be addressed in future research.
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Affiliation(s)
- Daniel J Müller
- ETH Zürich, Department of Biosystems Science and Engineering, Basel, Switzerland.
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15
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Liou JW, Gu MH, Chen YK, Chen WY, Chen YC, Tseng YH, Hung YJ, Chang HH. Visible light responsive photocatalyst induces progressive and apical-terminus preferential damages on Escherichia coli surfaces. PLoS One 2011; 6:e19982. [PMID: 21589873 PMCID: PMC3093399 DOI: 10.1371/journal.pone.0019982] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 04/22/2011] [Indexed: 01/10/2023] Open
Abstract
Background Recent research shows that visible-light responsive photocatalysts have potential usage in antimicrobial applications. However, the dynamic changes in the damage to photocatalyzed bacteria remain unclear. Methodology/Principal Findings Facilitated by atomic force microscopy, this study analyzes the visible-light driven photocatalyst-mediated damage of Escherichia coli. Results show that antibacterial properties are associated with the appearance of hole-like structures on the bacteria surfaces. Unexpectedly, these hole-like structures were preferentially induced at the apical terminus of rod shaped E. coli cells. Differentiating the damages into various levels and analyzing the percentage of damage to the cells showed that photocatalysis was likely to elicit sequential damages in E. coli cells. The process began with changing the surface properties on bacterial cells, as indicated in surface roughness measurements using atomic force microscopy, and holes then formed at the apical terminus of the cells. The holes were then subsequently enlarged until the cells were totally transformed into a flattened shape. Parallel experiments indicated that photocatalysis-induced bacterial protein leakage is associated with the progression of hole-like damages, further suggesting pore formation. Control experiments using ultraviolet light responsive titanium-dioxide substrates also obtained similar observations, suggesting that this is a general phenomenon of E. coli in response to photocatalysis. Conclusion/Significance The photocatalysis-mediated localization-preferential damage to E. coli cells reveals the weak points of the bacteria. This might facilitate the investigation of antibacterial mechanism of the photocatalysis.
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Affiliation(s)
- Je-Wen Liou
- Department of Biochemistry, Tzu Chi University, Hualien, Taiwan, Republic of China
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan, Republic of China
- Nanotechnology Research Center, National Dong-Hwa University, Hualien, Taiwan, Republic of China
| | - Ming-Hui Gu
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan, Republic of China
| | - Yen-Kai Chen
- Department of Biochemistry, Tzu Chi University, Hualien, Taiwan, Republic of China
| | - Wen-Yi Chen
- Department of Biochemistry, Tzu Chi University, Hualien, Taiwan, Republic of China
| | - Yi-Cheng Chen
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan, Republic of China
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan, Republic of China
| | - Yao-Hsuan Tseng
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, Republic of China
| | - Yu-Jiun Hung
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan, Republic of China
| | - Hsin-Hou Chang
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan, Republic of China
- Nanotechnology Research Center, National Dong-Hwa University, Hualien, Taiwan, Republic of China
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan, Republic of China
- * E-mail:
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16
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Atomic force microscopy analysis shows surface structure changes in carvacrol-treated bacterial cells. Res Microbiol 2011; 162:164-72. [DOI: 10.1016/j.resmic.2010.11.006] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 09/15/2010] [Indexed: 11/20/2022]
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Liu S, Ng AK, Xu R, Wei J, Tan CM, Yang Y, Chen Y. Antibacterial action of dispersed single-walled carbon nanotubes on Escherichia coli and Bacillus subtilis investigated by atomic force microscopy. NANOSCALE 2010; 2:2744-2750. [PMID: 20877897 DOI: 10.1039/c0nr00441c] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Single-walled carbon nanotubes (SWCNTs) exhibit strong antibacterial activities. Direct contact between bacterial cells and SWCNTs may likely induce cell damages. Therefore, the understanding of SWCNT-bacteria interactions is essential in order to develop novel SWCNT-based materials for their potential environmental, imaging, therapeutic, and military applications. In this preliminary study, we utilized atomic force microscopy (AFM) to monitor dynamic changes in cell morphology and mechanical properties of two typical bacterial models (gram-negative Escherichia coli and gram-positive Bacillus subtilis) upon incubation with SWCNTs. The results demonstrated that individually dispersed SWCNTs in solution develop nanotube networks on the cell surface, and then destroy the bacterial envelopes with leakage of the intracellular contents. The cell morphology changes observed on air dried samples are accompanied by an increase in cell surface roughness and a decrease in surface spring constant. To mimic the collision between SWCNTs and cells, a sharp AFM tip of 2 nm was chosen to introduce piercings on the cell surface. No clear physical damages were observed if the applied force was below 10 nN. Further analysis also indicates that a single collision between one nanotube and a bacterial cell is unlikely to introduce direct physical damage. Hence, the antibacterial activity of SWCNTs is the accumulation effect of large amount of nanotubes through interactions between SWCNT networks and bacterial cells.
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Affiliation(s)
- Shaobin Liu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459
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18
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Dupres V, Alsteens D, Andre G, Dufrêne YF. Microbial nanoscopy: a closer look at microbial cell surfaces. Trends Microbiol 2010; 18:397-405. [DOI: 10.1016/j.tim.2010.06.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 06/15/2010] [Accepted: 06/16/2010] [Indexed: 10/19/2022]
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Atomic force microscopy investigation of the morphology and topography of colistin-heteroresistant Acinetobacter baumannii strains as a function of growth phase and in response to colistin treatment. Antimicrob Agents Chemother 2009; 53:4979-86. [PMID: 19786595 DOI: 10.1128/aac.00497-09] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The prevalence of infections caused by multidrug-resistant gram-negative Acinetobacter baumannii strains and the lack of novel antibiotics under development are posing a global dilemma, forcing a resurgence of the last-line antibiotic colistin. Our aim was to use atomic force microscopy (AFM) to investigate the morphology and topography of paired colistin-susceptible and -resistant cells from colistin-heteroresistant A. baumannii strains as a function of bacterial growth phase and colistin exposure. An optimal AFM bacterial sample preparation protocol was established and applied to examine three paired strains. Images revealed rod-shaped colistin-susceptible cells (1.65 +/- 0.27 microm by 0.98 +/- 0.07 microm) at mid-logarithmic phase, in contrast to spherical colistin-resistant cells (1.03 +/- 0.09 microm); the latter were also more diverse in appearance and exhibited a rougher surface topography (7.05 +/- 1.3 nm versus 11.4 +/- 2.5 nm for susceptible versus resistant, respectively). Cellular elongation up to approximately 18 microm at stationary phase was more commonly observed in susceptible strains, although these "worm-like" cells were also observed occasionally in the resistant population. The effects of colistin exposure on the cell surface of colistin-susceptible and -resistant cells were found to be similar; topographical changes were minor in response to 0.5 microg/ml colistin; however, at 4 microg/ml colistin, a significant degree of surface disruption was detected. At 32 microg/ml colistin, cellular clumping and surface smoothening were evident. Our study has demonstrated for the first time substantial morphological and topographical differences between colistin-susceptible and -resistant cells from heteroresistant A. baumannii strains. These results contribute to an understanding of colistin action and resistance in regard to this problematic pathogen.
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Deupree SM, Schoenfisch MH. Morphological analysis of the antimicrobial action of nitric oxide on gram-negative pathogens using atomic force microscopy. Acta Biomater 2009; 5:1405-15. [PMID: 19250890 DOI: 10.1016/j.actbio.2009.01.025] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 01/08/2009] [Accepted: 01/26/2009] [Indexed: 11/18/2022]
Abstract
Atomic force microscopy (AFM) was used to study the morphological changes of two gram-negative pathogens, Pseudomonas aeruginosa and Escherichia coli, after exposure to nitric oxide (NO). The time-dependent effects of NO released from a xerogel coating and the concentration-dependent effects rendered by a small molecule that releases NO in a bolus were examined and compared. Bacteria exhibited irregular and degraded exteriors. With NO-releasing surfaces, an increase in surface debris and disorganized adhesion patterns were observed compared to controls. Analysis of cell surface topography revealed that increasing membrane roughness correlated with higher doses of NO. At a lower total dose, NO delivered via a bolus resulted in greater membrane roughness than NO released from a surface via a sustained flux. At sub-inhibitory levels, treatment with amoxicillin, an antibiotic known to compromise the integrity of the cell wall, led to morphologies resembling those resulting from NO treatment. Our observations indicate that cell envelope deterioration is a visible consequence of NO-exposure for both gram-negative species studied.
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Affiliation(s)
- Susan M Deupree
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Abstract
At the cross-roads of nanoscience and microbiology, the nanoscale analysis of microbial cells using atomic force microscopy (AFM) is an exciting, rapidly evolving research field. Over the past decade, there has been tremendous progress in our use of AFM to observe membrane proteins and live cells at high resolution. Remarkable advances have also been made in applying force spectroscopy to manipulate single membrane proteins, to map surface properties and receptor sites on cells and to measure cellular interactions at the single-cell and single-molecule levels. In addition, recent developments in cantilever nanosensors have opened up new avenues for the label-free detection of microorganisms and bioanalytes.
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Affiliation(s)
- Yves F Dufrêne
- Unité de chimie des interfaces, Université catholique de Louvain, Croix du Sud 2/18, B-1348 Louvain-la-Neuve, Belgium.
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Wang Y, Huang F, Pan D, Li B, Chen D, Lin W, Chen X, Li R, Lin Z. Ultraviolet-light-induced bactericidal mechanism on ZnO single crystals. Chem Commun (Camb) 2009:6783-5. [DOI: 10.1039/b912137d] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Yang L, Li H, Wang K, Tan W, Yang W, Zheng J. Atomic Force Microscopy Study of the Effect of Pulsed Electric Field on Staphylococcus epidermidis. Anal Chem 2008; 80:6222-7. [DOI: 10.1021/ac800556f] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Liu Yang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Biomedical Engineering Center, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province and College of Material Science and Engineering, Hunan University, Changsha 410082, P.R. China
| | - Huimin Li
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Biomedical Engineering Center, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province and College of Material Science and Engineering, Hunan University, Changsha 410082, P.R. China
| | - Kemin Wang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Biomedical Engineering Center, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province and College of Material Science and Engineering, Hunan University, Changsha 410082, P.R. China
| | - Weihong Tan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Biomedical Engineering Center, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province and College of Material Science and Engineering, Hunan University, Changsha 410082, P.R. China
| | - Wenjuan Yang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Biomedical Engineering Center, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province and College of Material Science and Engineering, Hunan University, Changsha 410082, P.R. China
| | - Jing Zheng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Biomedical Engineering Center, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province and College of Material Science and Engineering, Hunan University, Changsha 410082, P.R. China
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He X, Jin R, Yang L, Wang K, Li W, Tan W, Li H. Study on the specific interaction between angiogenin and aptamer by atomic force microscopy (AFM). ACTA ACUST UNITED AC 2008. [DOI: 10.1007/s11434-007-0494-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Diakowski PM, Ding Z. Interrogation of living cells using alternating current scanning electrochemical microscopy (AC-SECM). Phys Chem Chem Phys 2007; 9:5966-74. [PMID: 18004408 DOI: 10.1039/b711448f] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this paper we present the application of alternating current scanning electrochemical microscopy (AC-SECM) to the study of living cells. Commercial AFM instrumentation was modified to allow for performing robust AC-SECM measurements. Constant height AC imaging of the Cos-7 cells, performed directly in cell culture medium without the addition of a redox mediator, provided topographical information of the cell. Stationary tip measurements on the AC current were carried out to investigate the cellular activity of a single cell. The dependence of AC current magnitude on tip-to-sample separation distance was used to monitor real time changes in cell height of individual Cos-7 cells. Furthermore, AC-SECM was employed to observe changes in metabolic cellular activity stimulated by ethanol and phorbol-1,2-myristate-acetate-3. The effect of changing cellular activity on constant height AC-SECM imaging was also studied.
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Affiliation(s)
- Piotr M Diakowski
- Department of Chemistry, The University of Western Ontario, London, ON, Canada
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