1
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Ryoo D, Hwang H, Gumbart JC. Thicket and Mesh: How the Outer Membrane Can Resist Tension Imposed by the Cell Wall. J Phys Chem B 2024; 128:5371-5377. [PMID: 38787347 PMCID: PMC11163421 DOI: 10.1021/acs.jpcb.3c08510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 05/07/2024] [Accepted: 05/09/2024] [Indexed: 05/25/2024]
Abstract
The cell envelope of Gram-negative bacteria is composed of an outer membrane (OM) and an inner membrane (IM) and a peptidoglycan cell wall (CW) between them. Combined with Braun's lipoprotein (Lpp), which connects the OM and the CW, and numerous membrane proteins that exist in both OM and IM, the cell envelope creates a mechanically stable environment that resists various physical and chemical perturbations to the cell, including turgor pressure caused by the solute concentration difference between the cytoplasm of the cell and the extracellular environment. Previous computational studies have explored how individual components (OM, IM, and CW) can resist turgor pressure although combinations of them have been less well studied. To that end, we constructed multiple OM-CW systems, including the Lpp connections with the CW under increasing degrees of strain. The results show that the OM can effectively resist the tension imposed by the CW, shrinking by only 3-5% in area even when the CW is stretched to 2.5× its relaxed area. The area expansion modulus of the system increases with increasing CW strain, although the OM remains a significant contributor to the envelope's mechanical stability. Additionally, we find that when the protein TolC is embedded in the OM, its stiffness increases.
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Affiliation(s)
- David Ryoo
- Interdisciplinary
Bioengineering Graduate Program, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Hyea Hwang
- School
of Materials Science and Engineering, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - James C. Gumbart
- School
of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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2
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Mu M, Liu S, DeFlorio W, Hao L, Wang X, Salazar KS, Taylor M, Castillo A, Cisneros-Zevallos L, Oh JK, Min Y, Akbulut M. Influence of Surface Roughness, Nanostructure, and Wetting on Bacterial Adhesion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:5426-5439. [PMID: 37014907 PMCID: PMC10848269 DOI: 10.1021/acs.langmuir.3c00091] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/22/2023] [Indexed: 05/11/2023]
Abstract
Bacterial fouling is a persistent problem causing the deterioration and failure of functional surfaces for industrial equipment/components; numerous human, animal, and plant infections/diseases; and energy waste due to the inefficiencies at internal and external geometries of transport systems. This work gains new insights into the effect of surface roughness on bacterial fouling by systematically studying bacterial adhesion on model hydrophobic (methyl-terminated) surfaces with roughness scales spanning from ∼2 nm to ∼390 nm. Additionally, a surface energy integration framework is developed to elucidate the role of surface roughness on the energetics of bacteria and substrate interactions. For a given bacteria type and surface chemistry; the extent of bacterial fouling was found to demonstrate up to a 75-fold variation with surface roughness. For the cases showing hydrophobic wetting behavior, both increased effective surface area with increasing roughness and decreased activation energy with increased surface roughness was concluded to enhance the extent of bacterial adhesion. For the cases of superhydrophobic surfaces, the combination of factors including (i) the surpassing of Laplace pressure force of interstitial air over bacterial adhesive force, (ii) the reduced effective substrate area for bacteria wall due to air gaps to have direct/solid contact, and (iii) the reduction of attractive van der Waals force that holds adhering bacteria on the substrate were summarized to weaken the bacterial adhesion. Overall, this study is significant in the context of designing antifouling coatings and systems as well as explaining variations in bacterial contamination and biofilm formation processes on functional surfaces.
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Affiliation(s)
- Minchen Mu
- Artie
McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Shuhao Liu
- Artie
McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - William DeFlorio
- Artie
McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Li Hao
- School
of Chemistry and Chemical Engineering, Zhongkai
University of Agriculture and Engineering, Guangzhou, Guangdong 510225, P. R. China
| | - Xunhao Wang
- Department
of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Karla Solis Salazar
- Department
of Food Science and Technology, Texas A&M
University, College Station, Texas 77843, United States
| | - Matthew Taylor
- Department
of Food Science and Technology, Texas A&M
University, College Station, Texas 77843, United States
| | - Alejandro Castillo
- Department
of Food Science and Technology, Texas A&M
University, College Station, Texas 77843, United States
| | - Luis Cisneros-Zevallos
- Department
of Horticultural Sciences, Texas A&M
University, College Station, Texas 77843, United States
| | - Jun Kyun Oh
- Department
of Polymer Science and Engineering, Dankook
University, 152 Jukjeon-ro, Suji-gu, Yongin-si, Gyeonggi-do 16890, Republic of Korea
| | - Younjin Min
- Department
of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Mustafa Akbulut
- Artie
McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
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3
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Han R, Feng XQ, Vollmer W, Stoodley P, Chen J. Deciphering the adaption of bacterial cell wall mechanical integrity and turgor to different chemical or mechanical environments. J Colloid Interface Sci 2023; 640:510-520. [PMID: 36878069 DOI: 10.1016/j.jcis.2023.02.100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/16/2023] [Accepted: 02/19/2023] [Indexed: 02/24/2023]
Abstract
Bacteria adapt the mechanical properties of their cell envelope, including cell wall stiffness, turgor, and cell wall tension and deformation, to grow and survive in harsh environments. However, it remains a technical challenge to simultaneously determine these mechanical properties at a single cell level. Here we combined theoretical modelling with an experimental approach to quantify the mechanical properties and turgor of Staphylococcus epidermidis. It was found that high osmolarity leads to a decrease in both cell wall stiffness and turgor. We also demonstrated that the turgor change is associated with a change in the viscosity of the bacterial cell. We predicted that the cell wall tension is much higher in deionized (DI) water and it decreases with an increase in osmolality. We also found that an external force increases the cell wall deformation to reinforce its adherence to a surface and this effect can be more significant in lower osmolarity. Overall, our work highlights how bacterial mechanics supports survival in harsh environments and uncovers the adaption of bacterial cell wall mechanical integrity and turgor to osmotic and mechanical challenges.
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Affiliation(s)
- Rui Han
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Xi-Qiao Feng
- Institute of Biomechanics and Medical Engineering, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Paul Stoodley
- Department of Microbial Infection and Immunity and the Department of Orthopaedics, The Ohio State University, Columbus, OH 43210, United States; National Centre for Advanced Tribology at Southampton (nCATS), National Biofilm Innovation Centre (NBIC), Mechanical Engineering, University of Southampton, Southampton S017 1BJ, UK
| | - Jinju Chen
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
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4
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Han R, Vollmer W, Perry JD, Stoodley P, Chen J. Simultaneous determination of the mechanical properties and turgor of a single bacterial cell using atomic force microscopy. NANOSCALE 2022; 14:12060-12068. [PMID: 35946610 DOI: 10.1039/d2nr02577a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Bacterial mechanical properties (cell wall stiffness and turgor) are important factors for bacterial survival in harsh environments. For an individual bacterial cell, it is challenging to determine the cell wall stiffness and turgor simultaneously. In this study, we adopted a combined finite element modelling and mathematical modelling approach to simultaneously determine bacterial cell wall stiffness and turgor of an individual bacterial cell based on atomic force microscopy (AFM) nanoindentation. The mechanical properties and turgor of Staphylococcus epidermidis, determined by our method are consistent with other independent studies. For a given aqueous environment, bacterial cell wall stiffness increased linearly with an increase in turgor. Higher osmolarity leads to a decrease in both cell wall stiffness and turgor. We also demonstrated that the change of turgor is associated with a change in viscosity of the bacterial cell.
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Affiliation(s)
- Rui Han
- School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - John D Perry
- Microbiology Department, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE7 7DN, UK
| | - Paul Stoodley
- Department of Microbial Infection and Immunity and the Department of Orthopaedics, The Ohio State University, Columbus, OH, 43210, USA
- National Centre for Advanced Tribology at Southampton (nCATS), National Biofilm Innovation Centre (NBIC), Mechanical Engineering, University of Southampton, Southampton, S017 1BJ, UK
| | - Jinju Chen
- School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
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5
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Tsugawa S, Yamasaki Y, Horiguchi S, Zhang T, Muto T, Nakaso Y, Ito K, Takebayashi R, Okano K, Akita E, Yasukuni R, Demura T, Mimura T, Kawaguchi K, Hosokawa Y. Elastic shell theory for plant cell wall stiffness reveals contributions of cell wall elasticity and turgor pressure in AFM measurement. Sci Rep 2022; 12:13044. [PMID: 35915101 PMCID: PMC9343428 DOI: 10.1038/s41598-022-16880-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/18/2022] [Indexed: 11/09/2022] Open
Abstract
The stiffness of a plant cell in response to an applied force is determined not only by the elasticity of the cell wall but also by turgor pressure and cell geometry, which affect the tension of the cell wall. Although stiffness has been investigated using atomic force microscopy (AFM) and Young’s modulus of the cell wall has occasionally been estimated using the contact-stress theory (Hertz theory), the existence of tension has made the study of stiffness more complex. Elastic shell theory has been proposed as an alternative method; however, the estimation of elasticity remains ambiguous. Here, we used finite element method simulations to verify the formula of the elastic shell theory for onion (Allium cepa) cells. We applied the formula and simulations to successfully quantify the turgor pressure and elasticity of a cell in the plane direction using the cell curvature and apparent stiffness measured by AFM. We conclude that tension resulting from turgor pressure regulates cell stiffness, which can be modified by a slight adjustment of turgor pressure in the order of 0.1 MPa. This theoretical analysis reveals a path for understanding forces inherent in plant cells.
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Affiliation(s)
- Satoru Tsugawa
- Faculty of Systems Science and Technology, Akita Prefectural University, 84-4 Yurihonjo, Akita, 015-0055, Japan.
| | - Yuki Yamasaki
- Division of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan
| | - Shota Horiguchi
- Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Tokyo, 153-8505, Japan
| | - Tianhao Zhang
- Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Tokyo, 153-8505, Japan
| | - Takara Muto
- Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Tokyo, 153-8505, Japan
| | - Yosuke Nakaso
- Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Tokyo, 153-8505, Japan.,Yamada Noriaki Structural Design Office Co., Ltd, 1-5-63, Shinagawa, Tokyo, 141-0021, Japan
| | - Kenshiro Ito
- Division of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan
| | - Ryu Takebayashi
- Division of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan
| | - Kazunori Okano
- Division of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan
| | - Eri Akita
- Division of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan
| | - Ryohei Yasukuni
- Division of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.,Graduate School of Engineering, Osaka Institute of Technology, 5-16-1, Ohmiya, Asahi-ku, Osaka, 535-8535, Japan
| | - Taku Demura
- Division of Biological Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan
| | - Tetsuro Mimura
- Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan.,College of Bioscience and Biotechnology, National Cheng-Kung University, Taiwan No.1, University Road, Tainan City, 701, Taiwan
| | - Ken'ichi Kawaguchi
- Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Tokyo, 153-8505, Japan
| | - Yoichiroh Hosokawa
- Division of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.
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6
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In situ real-time investigation of Staphylococcus aureus on hemisphere-patterned polyurethane films. Colloids Surf B Biointerfaces 2022; 216:112577. [PMID: 35623259 DOI: 10.1016/j.colsurfb.2022.112577] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 05/05/2022] [Accepted: 05/12/2022] [Indexed: 11/23/2022]
Abstract
Surface patterning is a promising approach to prevent bacterial adhesion and biofilm formation without the concerns of antimicrobial resistance. To determine the parameters of a patterned surface that can affect bacterial behavior, a sphere-like coccus (Staphylococcus aureus) was investigated on a series of polyurethane films with ordered hemisphere patterns. The bacterial retention data in a growth medium indicated that the surface patterns significantly decreased bacterial adhesion and proliferation. The most notable effects were observed with the 2 µm-pattern as well as the patterned polycaprolactone and polystyrene films, and the accessible contact area of the polyurethane films, surface wettability, and spatial confinement, did not show an influence. An optical microscope with a modified incubation cell was used for in situ real-time observations of bacterial colonization, proliferation, and migration. Based on appropriate statistical analyses, it was concluded that topographical geometry played a dominant role. In combination with the retention assessment in a nongrowth medium, it was found that pattern-mediated inhibition of biofilm formation was mainly achieved by affecting bacterial proliferation rather than adhesion. This study provides new insight for designing biofilm-resistant biomimetic materials.
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7
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Ramalakshmi S, Ramanan RN, Madhavan S, Ooi CW, Chang CCH, Harper IS, Lewis DM, Lee AK, He L, Seenichamy A. Investigation of selective release of periplasmic proteins through pore size analysis and single-cell microscopy in Escherichia coli. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.108009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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8
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Greer HM, Overton K, Ferguson MA, Spain EM, Darling LEO, Núñez ME, Volle CB. Extracellular Polymeric Substance Protects Some Cells in an Escherichia coli Biofilm from the Biomechanical Consequences of Treatment with Magainin 2. Microorganisms 2021; 9:microorganisms9050976. [PMID: 33946431 PMCID: PMC8147140 DOI: 10.3390/microorganisms9050976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/26/2021] [Accepted: 04/29/2021] [Indexed: 11/16/2022] Open
Abstract
Bacterial biofilms have long been recognized as a source of persistent infections and industrial contamination with their intransigence generally attributed to their protective layer of extracellular polymeric substances (EPS). EPS, consisting of secreted nucleic acids, proteins, and polysaccharides, make it difficult to fully eliminate biofilms by conventional chemical or physical means. Since most bacteria are capable of forming biofilms, understanding how biofilms respond to new antibiotic compounds and components of the immune system has important ramifications. Antimicrobial peptides (AMPs) are both potential novel antibiotic compounds and part of the immune response in many different organisms. Here, we use atomic force microscopy to investigate the biomechanical changes that occur in individual cells when a biofilm is exposed to the AMP magainin 2 (MAG2), which acts by permeabilizing bacterial membranes. While MAG2 is able to prevent biofilm initiation, cells in an established biofilm can withstand exposure to high concentrations of MAG2. Treated cells in the biofilm are classified into two distinct populations after treatment: one population of cells is indistinguishable from untreated cells, maintaining cellular turgor pressure and a smooth outer surface, and the second population of cells are softer than untreated cells and have a rough outer surface after treatment. Notably, the latter population is similar to planktonic cells treated with MAG2. The EPS likely reduces the local MAG2 concentration around the stiffer cells since once the EPS was enzymatically removed, all cells became softer and had rough outer surfaces. Thus, while MAG2 appears to have the same mechanism of action in biofilm cells as in planktonic ones, MAG2 cannot eradicate a biofilm unless coupled with the removal of the EPS.
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Affiliation(s)
- Helen M. Greer
- Department of Biology, Cottey College, Nevada, MO 64772, USA; (H.M.G.); (K.O.)
| | - Kanesha Overton
- Department of Biology, Cottey College, Nevada, MO 64772, USA; (H.M.G.); (K.O.)
| | - Megan A. Ferguson
- Department of Chemistry, State University of New York, New Paltz, NY 12561, USA;
| | - Eileen M. Spain
- Department of Chemistry, Occidental College, Los Angeles, CA 90041, USA;
| | - Louise E. O. Darling
- Department of Biological Sciences and Program in Biochemistry, Wellesley College, Wellesley, MA 02481, USA;
| | - Megan E. Núñez
- Department of Chemistry and Program in Biochemistry, Wellesley College, Wellesley, MA 02481, USA;
| | - Catherine B. Volle
- Departments of Biology and Chemistry, Cornell College, Mount Vernon, IA 52314, USA
- Correspondence: ; Tel.: +1-(319)-895-4413
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9
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Zhang H, Wang H, Wilksch JJ, Strugnell RA, Gee ML, Feng XQ. Measurement of the interconnected turgor pressure and envelope elasticity of live bacterial cells. SOFT MATTER 2021; 17:2042-2049. [PMID: 33592087 DOI: 10.1039/d0sm02075c] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Turgor pressure and envelope elasticity of bacterial cells are two mechanical parameters that play a dominant role in cellular deformation, division, and motility. However, a clear understanding of these two properties is lacking because of their strongly interconnected mechanisms. This study established a nanoindentation method to precisely measure the turgor pressure and envelope elasticity of live bacteria. The indentation force-depth curves of Klebsiella pneumoniae bacteria were recorded with atomic force microscopy. Through combination of dimensional analysis and numerical simulations, an explicit expression was derived to decouple the two properties of individual bacteria from the nanoindentation curves. We show that the Young's modulus of bacterial envelope is sensitive to the external osmotic environment, and the turgor pressure is significantly dependent on the external osmotic stress. This method can not only quantify the turgor pressure and envelope elasticity of bacteria, but also help resolve the mechanical behaviors of bacteria in different environments.
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Affiliation(s)
- Huanxin Zhang
- Institute of Biomechanics and Medical Engineering, AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
| | - Huabin Wang
- Research Center of Applied Physics, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China. and Chongqing School, University of Chinese Academy of Sciences, Chongqing 400714, China and Chongqing Engineering Research Center of High-Resolution and Three-Dimensional Dynamic Imaging Technology, Chongqing 400714, China
| | - Jonathan J Wilksch
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Richard A Strugnell
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Michelle L Gee
- School of Aerospace Engineering and Aviation, RMIT University, Bundoora, Victoria 3083, Australia
| | - Xi-Qiao Feng
- Institute of Biomechanics and Medical Engineering, AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
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10
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Tran BM, Prabha H, Iyer A, O'Byrne C, Abee T, Poolman B. Measurement of Protein Mobility in Listeria monocytogenes Reveals a Unique Tolerance to Osmotic Stress and Temperature Dependence of Diffusion. Front Microbiol 2021; 12:640149. [PMID: 33679676 PMCID: PMC7925416 DOI: 10.3389/fmicb.2021.640149] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 01/21/2021] [Indexed: 11/18/2022] Open
Abstract
Protein mobility in the cytoplasm is essential for cellular functions, and slow diffusion may limit the rates of biochemical reactions in the living cell. Here, we determined the apparent lateral diffusion coefficient (DL) of GFP in Listeria monocytogenes as a function of osmotic stress, temperature, and media composition. We find that DL is much less affected by hyperosmotic stress in L. monocytogenes than under similar conditions in Lactococcus lactis and Escherichia coli. We find a temperature optimum for protein diffusion in L. monocytogenes at 30°C, which deviates from predicted trends from the generalized Stokes-Einstein equation under dilute conditions and suggests that the structure of the cytoplasm and macromolecular crowding vary as a function of temperature. The turgor pressure of L. monocytogenes is comparable to other Gram-positive bacteria like Bacillus subtilis and L. lactis but higher in a knockout strain lacking the stress-inducible sigma factor SigB. We discuss these findings in the context of how L. monocytogenes survives during environmental transmission and interaction with the human host.
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Affiliation(s)
- Buu Minh Tran
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
| | - Haritha Prabha
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
| | - Aditya Iyer
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
| | - Conor O'Byrne
- School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Tjakko Abee
- Laboratory of Food Microbiology, Wageningen University Research, Wageningen, Netherlands
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
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11
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Zhang X, Yang C, Xi T, Zhao J, Yang K. Surface Roughness of Cu-Bearing Stainless Steel Affects Its Contact-Killing Efficiency by Mediating the Interfacial Interaction with Bacteria. ACS APPLIED MATERIALS & INTERFACES 2021; 13:2303-2315. [PMID: 33395246 DOI: 10.1021/acsami.0c19655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Numerous studies have found that the surface topography affects the material antibacterial properties by reducing the attachment of bacteria on the surfaces without influencing the viability of the adhered cells. For Cu-bearing alloys with excellent contact-killing properties, bacterial adhesion on the surface is also accompanied by short-range interactions which regulate the toxic effects of the material surface against bacterial cells. Thus, the surface topography of Cu-bearing alloys, as an important factor dominating the exposure level of bacteria on the surfaces, should affect the subsequent contact-killing efficiency. In this work, our major focus was on the regulation mechanism of the surface features on the material-bacterial interactions. We correlated the surface properties including different surface roughnesses of Cu-bearing stainless steel (SS) with the bacterial damage pattern and attempted to clarify the role of surface roughness in mediating the contact-killing behavior of Cu-bearing SS. The results of both atomic force microscopy and scanning electron microscopy investigations showed that E. coli cells experienced the most rapid physical and mechanical damages after incubating with the diamond-polished Cu-bearing SS surface. The bacterial cells noticeably stiffened and the adhesion force significantly increased, as evidenced by force-distance curve measurements. Because of the enhanced hydrophobicity and higher surface potential of the diamond-polished surface, which strengthened the Lewis acid-base attractive forces and weakened the electrostatic barrier between the bacteria and the surface, a higher exposure surface for bacteria was generated. Furthermore, the contact-induced charge transfer, manifested by Cu ion burst release, and reactive oxygen species overexpression contribute to an efficient contact-killing process.
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Affiliation(s)
- Xinrui Zhang
- School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
- Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Chunguang Yang
- Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Tong Xi
- Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Jinlong Zhao
- Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Ke Yang
- Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
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12
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Cieśluk M, Deptuła P, Piktel E, Fiedoruk K, Suprewicz Ł, Paprocka P, Kot P, Pogoda K, Bucki R. Physics Comes to the Aid of Medicine-Clinically-Relevant Microorganisms through the Eyes of Atomic Force Microscope. Pathogens 2020; 9:pathogens9110969. [PMID: 33233696 PMCID: PMC7699805 DOI: 10.3390/pathogens9110969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 12/01/2022] Open
Abstract
Despite the hope that was raised with the implementation of antibiotics to the treatment of infections in medical practice, the initial enthusiasm has substantially faded due to increasing drug resistance in pathogenic microorganisms. Therefore, there is a need for novel analytical and diagnostic methods in order to extend our knowledge regarding the mode of action of the conventional and novel antimicrobial agents from a perspective of single microbial cells as well as their communities growing in infected sites, i.e., biofilms. In recent years, atomic force microscopy (AFM) has been mostly used to study different aspects of the pathophysiology of noninfectious conditions with attempts to characterize morphological and rheological properties of tissues, individual mammalian cells as well as their organelles and extracellular matrix, and cells’ mechanical changes upon exposure to different stimuli. At the same time, an ever-growing number of studies have demonstrated AFM as a valuable approach in studying microorganisms in regard to changes in their morphology and nanomechanical properties, e.g., stiffness in response to antimicrobial treatment or interaction with a substrate as well as the mechanisms behind their virulence. This review summarizes recent developments and the authors’ point of view on AFM-based evaluation of microorganisms’ response to applied antimicrobial treatment within a group of selected bacteria, fungi, and viruses. The AFM potential in development of modern diagnostic and therapeutic methods for combating of infections caused by drug-resistant bacterial strains is also discussed.
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Affiliation(s)
- Mateusz Cieśluk
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
| | - Piotr Deptuła
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
| | - Ewelina Piktel
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
| | - Krzysztof Fiedoruk
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
| | - Łukasz Suprewicz
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
| | - Paulina Paprocka
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University in Kielce, PL-25317 Kielce, Poland; (P.P.); (P.K.)
| | - Patrycja Kot
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University in Kielce, PL-25317 Kielce, Poland; (P.P.); (P.K.)
| | - Katarzyna Pogoda
- Institute of Nuclear Physics Polish Academy of Sciences, PL-31342 Krakow, Poland;
| | - Robert Bucki
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
- Correspondence:
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13
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Xie Y, Qu X, Li J, Li D, Wei W, Hui D, Zhang Q, Meng F, Yin H, Xu X, Wang Y, Wang L, Zhou Z. Ultrafast physical bacterial inactivation and photocatalytic self-cleaning of ZnO nanoarrays for rapid and sustainable bactericidal applications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 738:139714. [PMID: 32531587 PMCID: PMC7266591 DOI: 10.1016/j.scitotenv.2020.139714] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/07/2020] [Accepted: 05/24/2020] [Indexed: 05/09/2023]
Abstract
Various nanostructured surfaces have been developed recently to physically inactivate bacteria, for reducing the rapidly spreading threat of pathogenic bacteria. However, it generally takes several hours for these surfaces to inactivate most of the bacteria, which greatly limits their application in the fields favoring rapid bactericidal performance. Besides, the accumulated bacteria debris left on these surfaces is rarely discussed in the previous reports. Herein we report the nanotip-engineered ZnO nanoarrays (NAs) with ultrafast physical bactericidal rate and the ability to photocatalytically remove the bacteria debris. Neither chemical (Zn2+ or reactive oxygen species) nor photocatalytic effect leads to the ultrafast bactericidal rate, where 97.5% of E. coli and 94.9% of S. aureus are inactivated within only 1 min. The simulation analysis further supported our proposed mechanism attributing the ultrafast bactericidal activity to the great stress enabled by the uneven topography. Moreover, the re-exposure of the ZnO NAs nanotips can be achieved in only 10 min under a mild UV light source. This study not only presents an ultrafast physical bactericidal activity, but also demonstrates the potential of the recyclable and photocatalytic self-cleaning functions of theses surfaces for applications that desire rapid and sustainable bactericidal performance.
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Affiliation(s)
- Yuan Xie
- School of Materials Science and Engineering, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Xi Qu
- Beijing Space Technology Research and Test Center, China Academy of Space Technology, Beijing 100094, China
| | - Jinyang Li
- School of Materials Science and Engineering, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China.
| | - Da Li
- School of Materials Science and Engineering, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Wei Wei
- School of Materials Science and Engineering, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - David Hui
- Department of Mechanical Engineering, University of New Orleans, New Orleans, LA 70148, USA
| | - Qiao Zhang
- School of Materials Science and Engineering, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Fanbin Meng
- School of Materials Science and Engineering, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Hong Yin
- Shenzhou Space Biology Science and Technology (Group) Co., Ltd., Beijing 100190, China
| | - Xiaoling Xu
- School of Materials Science and Engineering, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Yong Wang
- School of Materials Science and Engineering, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Li Wang
- Qian Xuesen Laboratory of Space Technology, Beijing 100094, China.
| | - Zuowan Zhou
- School of Materials Science and Engineering, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China.
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14
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Grzeszczuk Z, Rosillo A, Owens Ó, Bhattacharjee S. Atomic Force Microscopy (AFM) As a Surface Mapping Tool in Microorganisms Resistant Toward Antimicrobials: A Mini-Review. Front Pharmacol 2020; 11:517165. [PMID: 33123004 PMCID: PMC7567160 DOI: 10.3389/fphar.2020.517165] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 09/14/2020] [Indexed: 12/28/2022] Open
Abstract
The worldwide emergence of antimicrobial resistance (AMR) in pathogenic microorganisms, including bacteria and viruses due to a plethora of reasons, such as genetic mutation and indiscriminate use of antimicrobials, is a major challenge faced by the healthcare sector today. One of the issues at hand is to effectively screen and isolate resistant strains from sensitive ones. Utilizing the distinct nanomechanical properties (e.g., elasticity, intracellular turgor pressure, and Young’s modulus) of microbes can be an intriguing way to achieve this; while atomic force microscopy (AFM), with or without modification of the tips, presents an effective way to investigate such biophysical properties of microbial surfaces or an entire microbial cell. Additionally, advanced AFM instruments, apart from being compatible with aqueous environments—as often is the case for biological samples—can measure the adhesive forces acting between AFM tips/cantilevers (conjugated to bacterium/virion, substrates, and molecules) and target cells/surfaces to develop informative force-distance curves. Moreover, such force spectroscopies provide an idea of the nature of intercellular interactions (e.g., receptor-ligand) or propensity of microbes to aggregate into densely packed layers, that is, the formation of biofilms—a property of resistant strains (e.g., Staphylococcus aureus, Pseudomonas aeruginosa). This mini-review will revisit the use of single-cell force spectroscopy (SCFS) and single-molecule force spectroscopy (SMFS) that are emerging as powerful additions to the arsenal of researchers in the struggle against resistant microbes, identify their strengths and weakness and, finally, prioritize some future directions for research.
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Affiliation(s)
| | | | - Óisín Owens
- School of Physics, Technological University Dublin, Dublin, Ireland
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15
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Juma A, Lemoine P, Simpson ABJ, Murray J, O'Hagan BMG, Naughton PJ, Dooley JG, Banat IM. Microscopic Investigation of the Combined Use of Antibiotics and Biosurfactants on Methicillin Resistant Staphylococcus aureus. Front Microbiol 2020; 11:1477. [PMID: 32733412 PMCID: PMC7358407 DOI: 10.3389/fmicb.2020.01477] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 06/05/2020] [Indexed: 12/13/2022] Open
Abstract
One current strategy to deal with the serious issue of antibiotic resistance is to use biosurfactants, weak antimicrobials in their own right, with antibiotics in order to extend the efficacy of antibiotics. Although an adjuvant effect has been observed, the underlying mechanisms are poorly understood. To investigate the nature of the antibiotic and biosurfactant interaction, we undertook a scanning electron microscopy (SEM) and atomic force microscopy (AFM) microscopic study of the effects of the tetracycline antibiotic, combined with sophorolipid and rhamnolipid biosurfactants, on Methicillin-resistant Staphylococcus aureus using tetracycline concentrations below and above the minimum inhibitory concentration (MIC). Control and treated bacterial samples were prepared with an immersion technique by adsorbing the bacteria onto glass substrates grafted with the poly-cationic polymer polyethyleneimine. Bacterial surface morphology, hydrophobic and hydrophilic surface characters as well as the local bacterial cell stiffness were measured following combined antibiotic and biosurfactant treatment. The sophorolipid biosurfactant stands alone insofar as, when used with the antibiotic at sub-MIC concentration, it resulted in bacterial morphological changes, larger diameters (from 758 ± 75 to 1276 ± 220 nm, p-value = 10-4) as well as increased bacterial core stiffness (from 205 ± 46 to 396 ± 66 mN/m, p-value = 5 × 10-5). This investigation demonstrates that such combination of microscopic analysis can give useful information which could complement biological assays to understand the mechanisms of synergy between antibiotics and bioactive molecules such as biosurfactants.
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Affiliation(s)
- Abulaziz Juma
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
| | - Patrick Lemoine
- School of Engineering, Nanotechnology and Integrated Bioengineering Centre (NIBEC), Ulster University, Newtownabbey, United Kingdom
| | - Alistair B J Simpson
- School of Engineering, Nanotechnology and Integrated Bioengineering Centre (NIBEC), Ulster University, Newtownabbey, United Kingdom
| | - Jason Murray
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
| | - Barry M G O'Hagan
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
| | - Patrick J Naughton
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
| | - James G Dooley
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
| | - Ibrahim M Banat
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
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16
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Harper CE, Hernandez CJ. Cell biomechanics and mechanobiology in bacteria: Challenges and opportunities. APL Bioeng 2020; 4:021501. [PMID: 32266323 PMCID: PMC7113033 DOI: 10.1063/1.5135585] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/27/2020] [Indexed: 12/11/2022] Open
Abstract
Physical forces play a profound role in the survival and function of all known forms of life. Advances in cell biomechanics and mechanobiology have provided key insights into the physiology of eukaryotic organisms, but much less is known about the roles of physical forces in bacterial physiology. This review is an introduction to bacterial mechanics intended for persons familiar with cells and biomechanics in mammalian cells. Bacteria play a major role in human health, either as pathogens or as beneficial commensal organisms within the microbiome. Although bacteria have long been known to be sensitive to their mechanical environment, understanding the effects of physical forces on bacterial physiology has been limited by their small size (∼1 μm). However, advancements in micro- and nano-scale technologies over the past few years have increasingly made it possible to rigorously examine the mechanical stress and strain within individual bacteria. Here, we review the methods currently used to examine bacteria from a mechanical perspective, including the subcellular structures in bacteria and how they differ from those in mammalian cells, as well as micro- and nanomechanical approaches to studying bacteria, and studies showing the effects of physical forces on bacterial physiology. Recent findings indicate a large range in mechanical properties of bacteria and show that physical forces can have a profound effect on bacterial survival, growth, biofilm formation, and resistance to toxins and antibiotics. Advances in the field of bacterial biomechanics have the potential to lead to novel antibacterial strategies, biotechnology approaches, and applications in synthetic biology.
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Affiliation(s)
- Christine E. Harper
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, USA
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17
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Lipoprotein Lpp regulates the mechanical properties of the E. coli cell envelope. Nat Commun 2020; 11:1789. [PMID: 32286264 PMCID: PMC7156740 DOI: 10.1038/s41467-020-15489-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 03/09/2020] [Indexed: 12/16/2022] Open
Abstract
The mechanical properties of the cell envelope in Gram-negative bacteria are controlled by the peptidoglycan, the outer membrane, and the proteins interacting with both layers. In Escherichia coli, the lipoprotein Lpp provides the only covalent crosslink between the outer membrane and the peptidoglycan. Here, we use single-cell atomic force microscopy and genetically engineered strains to study the contribution of Lpp to cell envelope mechanics. We show that Lpp contributes to cell envelope stiffness in two ways: by covalently connecting the outer membrane to the peptidoglycan, and by controlling the width of the periplasmic space. Furthermore, mutations affecting Lpp function substantially increase bacterial susceptibility to the antibiotic vancomycin, indicating that Lpp-dependent effects can affect antibacterial drug efficacy. Lipoprotein Lpp provides a covalent crosslink between the outer membrane and the peptidoglycan in E. coli. Here, the authors use atomic force microscopy to show that Lpp contributes to cell envelope stiffness by covalently connecting the two layers and by controlling the width of the periplasmic space.
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18
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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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19
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Abstract
Antimicrobial peptides (AMPs) are one of the most promising alternatives to conventional antibiotics. Atomic force microscopy (AFM), as imaging and force spectroscopy tool, has been applied to study their mechanism of action and development. Here, we describe different methods to be applied in the study of AMP effects on bacteria, either by imaging or by force spectroscopy studies, essential to underlie their action and to identify possibly outcomes of the same.
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Affiliation(s)
- Marco M Domingues
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
| | - Mário R Felício
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Sónia Gonçalves
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
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20
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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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21
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Distribution of mechanical stress in the Escherichia coli cell envelope. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2566-2575. [PMID: 30278180 DOI: 10.1016/j.bbamem.2018.09.020] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 09/14/2018] [Accepted: 09/26/2018] [Indexed: 01/05/2023]
Abstract
The cell envelope in Gram-negative bacteria comprises two distinct membranes with a cell wall between them. There has been a growing interest in understanding the mechanical adaptation of this cell envelope to the osmotic pressure (or turgor pressure), which is generated by the difference in the concentration of solutes between the cytoplasm and the external environment. However, it remains unexplored how the cell wall, the inner membrane (IM), and the outer membrane (OM) effectively protect the cell from this pressure by bearing the resulting surface tension, thus preventing the formation of inner membrane bulges, abnormal cell morphology, spheroplasts and cell lysis. In this study, we have used molecular dynamics (MD) simulations combined with experiments to resolve how and to what extent models of the IM, OM, and cell wall respond to changes in surface tension. We calculated the area compressibility modulus of all three components in simulations from tension-area isotherms. Experiments on monolayers mimicking individual leaflets of the IM and OM were also used to characterize their compressibility. While the membranes become softer as they expand, the cell wall exhibits significant strain stiffening at moderate to high tensions. We integrate these results into a model of the cell envelope in which the OM and cell wall share the tension at low turgor pressure (0.3 atm) but the tension in the cell wall dominates at high values (>1 atm).
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22
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Even C, Marlière C, Ghigo JM, Allain JM, Marcellan A, Raspaud E. Recent advances in studying single bacteria and biofilm mechanics. Adv Colloid Interface Sci 2017; 247:573-588. [PMID: 28754382 DOI: 10.1016/j.cis.2017.07.026] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/18/2017] [Accepted: 07/18/2017] [Indexed: 12/15/2022]
Abstract
Bacterial biofilms correspond to surface-associated bacterial communities embedded in hydrogel-like matrix, in which high cell density, reduced diffusion and physico-chemical heterogeneity play a protective role and induce novel behaviors. In this review, we present recent advances on the understanding of how bacterial mechanical properties, from single cell to high-cell density community, determine biofilm tri-dimensional growth and eventual dispersion and we attempt to draw a parallel between these properties and the mechanical properties of other well-studied hydrogels and living systems.
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23
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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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24
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Critical role of quorum sensing-dependent glutamate metabolism in homeostatic osmolality and outer membrane vesiculation in Burkholderia glumae. Sci Rep 2017; 7:44195. [PMID: 28272446 PMCID: PMC5341150 DOI: 10.1038/srep44195] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 02/03/2017] [Indexed: 02/08/2023] Open
Abstract
Metabolic homeostasis in cooperative bacteria is achieved by modulating primary metabolism in a quorum sensing (QS)-dependent manner. A perturbed metabolism in QS mutants causes physiological stress in the rice bacterial pathogen Burkholderia glumae. Here, we show that increased bacterial osmolality in B. glumae is caused by unusually high cellular concentrations of glutamate and betaine generated by QS deficiencies. QS negatively controls glutamate uptake and the expression of genes involved in the glutamine synthetase and glutamine oxoglutarate aminotransferase cycles. Thus, cellular glutamate levels were significantly higher in the QS mutants than in the wild type, and they caused hyperosmotic cellular conditions. Under the hypotonic conditions of the periplasm in the QS mutants, outer membrane bulging and vesiculation were observed, although these changes were rescued by knocking out the gltI gene, which encodes a glutamate transporter. Outer membrane modifications were not detected in the wild type. These results suggest that QS-dependent glutamate metabolism is critical for homeostatic osmolality. We suggest that outer membrane bulging and vesiculation might be the outcome of a physiological adaptation to relieve hypotonic osmotic stress in QS mutants. Our findings reveal how QS functions to maintain bacterial osmolality in a cooperative population.
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25
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Gaveau A, Coetsier C, Roques C, Bacchin P, Dague E, Causserand C. Bacteria transfer by deformation through microfiltration membrane. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2016.10.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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26
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27
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van der Westen R, Sharma PK, De Raedt H, Vermue I, van der Mei HC, Busscher HJ. Elastic and viscous bond components in the adhesion of colloidal particles and fibrillated streptococci to QCM-D crystal surfaces with different hydrophobicities using Kelvin–Voigt and Maxwell models. Phys Chem Chem Phys 2017; 19:25391-25400. [DOI: 10.1039/c7cp04676f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Analysis of initial bacterial adhesion using phenomenological models such as the Kelvin–Voigt model and the Maxwell model.
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Affiliation(s)
- Rebecca van der Westen
- University of Groningen and University Medical Center Groningen
- Department of Biomedical Engineering
- Groningen
- The Netherlands
| | - Prashant K. Sharma
- University of Groningen and University Medical Center Groningen
- Department of Biomedical Engineering
- Groningen
- The Netherlands
| | - Hans De Raedt
- Faculty of Mathematics and Natural Sciences
- Computational Physics
- Zernike Institute for Advanced Materials
- 9747 AG Groningen
- The Netherlands
| | - Ijsbrand Vermue
- University of Groningen and University Medical Center Groningen
- Department of Biomedical Engineering
- Groningen
- The Netherlands
| | - Henny C. van der Mei
- University of Groningen and University Medical Center Groningen
- Department of Biomedical Engineering
- Groningen
- The Netherlands
| | - Henk J. Busscher
- University of Groningen and University Medical Center Groningen
- Department of Biomedical Engineering
- Groningen
- The Netherlands
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28
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Dynamics of Escherichia coli's passive response to a sudden decrease in external osmolarity. Proc Natl Acad Sci U S A 2016; 113:E5838-E5846. [PMID: 27647888 DOI: 10.1073/pnas.1522185113] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
For most cells, a sudden decrease in external osmolarity results in fast water influx that can burst the cell. To survive, cells rely on the passive response of mechanosensitive channels, which open under increased membrane tension and allow the release of cytoplasmic solutes and water. Although the gating and the molecular structure of mechanosensitive channels found in Escherichia coli have been extensively studied, the overall dynamics of the whole cellular response remain poorly understood. Here, we characterize E. coli's passive response to a sudden hypoosmotic shock (downshock) on a single-cell level. We show that initial fast volume expansion is followed by a slow volume recovery that can end below the initial value. Similar response patterns were observed at downshocks of a wide range of magnitudes. Although wild-type cells adapted to osmotic downshocks and resumed growing, cells of a double-mutant ([Formula: see text]) strain expanded, but failed to fully recover, often lysing or not resuming growth at high osmotic downshocks. We propose a theoretical model to explain our observations by simulating mechanosensitive channels opening, and subsequent solute efflux and water flux. The model illustrates how solute efflux, driven by mechanical pressure and solute chemical potential, competes with water influx to reduce cellular osmotic pressure and allow volume recovery. Our work highlights the vital role of mechanosensation in bacterial survival.
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29
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Perni S, Preedy EC, Landini P, Prokopovich P. Influence of csgD and ompR on Nanomechanics, Adhesion Forces, and Curli Properties of E. coli. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:7965-7974. [PMID: 27434665 DOI: 10.1021/acs.langmuir.6b02342] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Curli are bacterial appendages involved in the adhesion of cells to surfaces; their synthesis is regulated by many genes such as csgD and ompR. The expression of the two curli subunits (CsgA and CsgB) in Escherichia coli (E. coli) is regulated by CsgD; at the same time, csgD transcription is under the control of OmpR. Therefore, both genes are involved in the control of curli production. In this work, we elucidated the role of these genes in the nanomechanical and adhesive properties of E. coli MG1655 (a laboratory strain not expressing significant amount of curli) and its curli-producing mutants overexpressing OmpR and CsgD, employing atomic force microscopy (AFM). Nanomechanical analysis revealed that the expression of these genes gave origin to cells with a lower Young's modulus (E) and turgidity (P0), whereas the adhesion forces were unaffected when genes involved in curli formation were expressed. AFM was also employed to study the primary structure of the curli expressed through the freely jointed chain (FJC) model for polymers. CsgD increased the number of curli on the surface more than OmpR did, and the overexpression of both genes did not result in a greater number of curli. Neither of the genes had an impact on the structure (total length of the polymer and number and length of Kuhn segments) of the curli. Our results further suggest that, despite the widely assumed role of curli in cell adhesion, cell adhesion force is also dictated by surface properties because no relation between the number of curli expressed on the surface and cell adhesion was found.
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Affiliation(s)
- Stefano Perni
- Cardiff School of Pharmacy and Pharmaceutical Science, Cardiff University , Cardiff, U.K. CF10 3NB
| | - Emily Callard Preedy
- Cardiff School of Pharmacy and Pharmaceutical Science, Cardiff University , Cardiff, U.K. CF10 3NB
| | - Paolo Landini
- Department of Biomolecular Sciences and Biotechnology, University of Milan , 20122 Milan, Italy
| | - Polina Prokopovich
- Cardiff School of Pharmacy and Pharmaceutical Science, Cardiff University , Cardiff, U.K. CF10 3NB
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Kundukad B, Seviour T, Liang Y, Rice SA, Kjelleberg S, Doyle PS. Mechanical properties of the superficial biofilm layer determine the architecture of biofilms. SOFT MATTER 2016; 12:5718-26. [PMID: 27273453 DOI: 10.1039/c6sm00687f] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Cells in biofilms sense and interact with their environment through the extracellular matrix. The physicochemical properties of the matrix, particularly at the biofilm-environment interface, determine how cells respond to changing conditions. In this study we describe the application of atomic force microscopy and confocal imaging to probe in situ the mechanical properties of these interfacial regions and to elucidate how key matrix components can contribute to the physical sensing by the cells. We describe how the Young's modulus of microcolonies differs according to the size and morphology of microcolonies, as well as the flow rate. The Young's modulus increased as a function of microcolony diameter, which was correlated with the production of the polysaccharide Psl at later stages of maturation for hemispherical or mushroom shaped microcolonies. The Young's modulus of the periphery of the biofilm colony was however independent of the hydrodynamic shear. The morphology of the microcolonies also influenced interfacial or peripheral stiffness. Microcolonies with a diffuse morphology had a lower Young's modulus than isolated, circular ones and this phenomenon was due to a deficiency of Psl. In this way, changes in the specific polysaccharide components imbue the biofilm with distinct physical properties that may modulate the way in which bacteria perceive or respond to their environment. Further, the physical properties of the polysaccharides are closely linked to the specific architectures formed by the developing biofilm.
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Affiliation(s)
- Binu Kundukad
- BioSystems and Micromechanics (BioSym) IRG, Singapore MIT Alliance for Research and Technology (SMART), Singapore
| | - Thomas Seviour
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Yang Liang
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore and School of Biological Sciences, Nanyang Technological University, Singapore
| | - Scott A Rice
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore and School of Biological Sciences, Nanyang Technological University, Singapore and Centre for Marine Bio-Innovation and School of Biotechnology and Biomolecular Science, University of New South Wales, Sydney, NSW, Australia
| | - Staffan Kjelleberg
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore and School of Biological Sciences, Nanyang Technological University, Singapore and Centre for Marine Bio-Innovation and School of Biotechnology and Biomolecular Science, University of New South Wales, Sydney, NSW, Australia
| | - Patrick S Doyle
- BioSystems and Micromechanics (BioSym) IRG, Singapore MIT Alliance for Research and Technology (SMART), Singapore and Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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Smolyakov G, Formosa-Dague C, Severac C, Duval R, Dague E. High speed indentation measures by FV, QI and QNM introduce a new understanding of bionanomechanical experiments. Micron 2016; 85:8-14. [DOI: 10.1016/j.micron.2016.03.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/03/2016] [Accepted: 03/05/2016] [Indexed: 12/31/2022]
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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: 9] [Impact Index Per Article: 1.1] [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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Lunov O, Zablotskii V, Churpita O, Jäger A, Polívka L, Syková E, Dejneka A, Kubinová Š. The interplay between biological and physical scenarios of bacterial death induced by non-thermal plasma. Biomaterials 2015; 82:71-83. [PMID: 26761777 DOI: 10.1016/j.biomaterials.2015.12.027] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 12/19/2015] [Indexed: 02/06/2023]
Abstract
Direct interactions of plasma matter with living cells and tissues can dramatically affect their functionality, initiating many important effects from cancer elimination to bacteria deactivation. However, the physical mechanisms and biochemical pathways underlying the effects of non-thermal plasma on bacteria and cell fate have still not been fully explored. Here, we report on the molecular mechanisms of non-thermal plasma-induced bacteria inactivation in both Gram-positive and Gram-negative strains. We demonstrate that depending on the exposure time plasma induces either direct physical destruction of bacteria or triggers programmed cell death (PCD) that exhibits characteristic features of apoptosis. The interplay between physical disruption and PCD is on the one hand driven by physical plasma parameters, and on the other hand by biological and physical properties of bacteria. The explored possibilities of the tuneable bacteria deactivation provide a basis for the development of advanced plasma-based therapies. To a great extent, our study opens new possibilities for controlled non-thermal plasma interactions with living systems.
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Affiliation(s)
- Oleg Lunov
- Institute of Physics AS CR, Prague, Czech Republic.
| | | | | | - Ales Jäger
- Institute of Physics AS CR, Prague, Czech Republic
| | - Leoš Polívka
- Institute of Physics AS CR, Prague, Czech Republic
| | - Eva Syková
- Institute of Experimental Medicine AS CR, Prague, Czech Republic
| | | | - Šárka Kubinová
- Institute of Physics AS CR, Prague, Czech Republic; Institute of Experimental Medicine AS CR, Prague, Czech Republic
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Abstract
Studies on the deformation behaviours of cellular entities, such as coated microbubbles and liposomes subject to a cavitation flow, become increasingly important for the advancement of ultrasonic imaging and drug delivery. Numerical simulations for bubble dynamics of ultrasound contrast agents based on the boundary integral method are presented in this work. The effects of the encapsulating shell are estimated by adapting Hoff's model used for thin-shell contrast agents. The viscosity effects are estimated by including the normal viscous stress in the boundary condition. In parallel, mechanical models of cell membranes and liposomes as well as state-of-the-art techniques for quantitative measurement of viscoelasticity for a single cell or coated microbubbles are reviewed. The future developments regarding modelling and measurement of the material properties of the cellular entities for cutting-edge biomedical applications are also discussed.
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Affiliation(s)
- Qianxi Wang
- School of Mathematics , University of Birmingham , Birmingham B15 2TY , UK
| | - Kawa Manmi
- School of Mathematics , University of Birmingham , Birmingham B15 2TY , UK ; Department of Mathematics, College of Science , Salahaddin University-Erbil , Kurdistan Region , Iraq
| | - Kuo-Kang Liu
- School of Engineering , University of Warwick , Coventry CV4 7AL , UK
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Sterilization of polydimethylsiloxane surface with Chinese herb extract: a new antibiotic mechanism of chlorogenic acid. Sci Rep 2015; 5:10464. [PMID: 25993914 PMCID: PMC4650805 DOI: 10.1038/srep10464] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 04/15/2015] [Indexed: 11/08/2022] Open
Abstract
Coating of polydimethylsiloxane (PDMS) surface with a traditional Chinese herb extract chlorogenic acid (CA) solves the contemporary problem of sterilization of PDMS surface. The E. coli grows slower and has a higher death rate on the CA-coated PDMS surfaces. A smoother morphology of these E. coli cell wall is observed by atomic force microscopy (AFM). Unlike the reported mechanism, where CA inhibits bacterial growth by damaging the cell membrane in the bulk solution, we find the CA-coated PDMS surface also decreases the stiffness of the cell wall. A decrease in the Young's modulus of the cell wall from 3 to 0.8 MPa is reported. Unexpectedly, the CA effect on the swarming ability and the biofilm stability of the bacteria can be still observed, even after they have been removed from the CA environment, indicating a decrease in their resistance to antibiotics for a prolonged time. The CA-coated PDMS surface shows better antibiotic effect against three types of both Gram-positive and Gran-negative bacteria than the gentamicin-coated PDMS surface. Coating of CA on PDMS surface not only solves the problem of sterilization of PDMS surface, but also shines light on the application of Chinese traditional herbs in scientific research.
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36
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Nanomechanical properties of the sea-water bacterium Paracoccus seriniphilus--a scanning force microscopy approach. Biointerphases 2015; 10:019004. [PMID: 25708634 DOI: 10.1116/1.4906862] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The measurement of force-distance curves on a single bacterium provides a unique opportunity to detect properties such as the turgor pressure under various environmental conditions. Marine bacteria are very interesting candidates for the production of pharmaceuticals, but are only little studied so far. Therefore, the elastic behavior of Paracoccus seriniphilus, an enzyme producing marine organism, is presented in this study. After a careful evaluation of the optimal measurement conditions, the spring constant and the turgor pressure are determined as a function of ionic strength and pH. Whereas the ionic strength changes the turgor pressure passively, the results give a hint that the change to acidic pH increases the turgor pressure by an active mechanism. Furthermore, it could be shown, that P. seriniphilus has adhesive protrusions outside its cell wall.
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37
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Effect of extracellular polymeric substances on the mechanical properties of Rhodococcus. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:518-26. [DOI: 10.1016/j.bbamem.2014.11.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 11/01/2014] [Accepted: 11/06/2014] [Indexed: 11/19/2022]
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38
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Mechanical and cell-to-cell adhesive properties of aggregated Methanosarcina. Colloids Surf B Biointerfaces 2015; 126:303-12. [PMID: 25578422 DOI: 10.1016/j.colsurfb.2014.12.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 09/15/2014] [Accepted: 12/19/2014] [Indexed: 11/20/2022]
Abstract
The mechanical and adhesive properties as well as the turgor pressure of microbes play an important role in cell growth and aggregation. By applying AFM together with finite element modelling, one can determine the cell wall structural homogeneity, mechanical and cell-to-cell adhesive properties for aggregated Methanosarcina barkeri cells. This also allows a novel approach to determine in-aggregate turgor pressure determination. Analyzing the AFM force-indentation response of the aggregates under loads less than 10 nN, our study reveals structural inhomogeneity of the polymeric part of the cell wall material and suggests that the cell wall consists of two layers of methanochondroitin (external: with a thickness of 3 ± 1 nm and internal: with a thickness of 169 ± 30 nm). On average, the hyperelastic finite element model showed that the internal layer is more rigid (μ = 14 ± 4 MPa) than the external layer (μ = 2.8 ± 0.9 MPa). To determine the turgor pressure and adhesiveness of the cells, a specific mode of indentation (under a load of 45 nN), aimed towards the centre of the individual aggregate, was performed. By modelling the AFM induced decohesion of the aggregate, the turgor pressure and the cell-to-cell adhesive interface properties could be determined. On average, the turgor pressure is estimated to be 59 ± 22 kPa, the interface strength is 78 ± 12 kPa and the polymer network extensibility is 2.8 ± 0.9 nm. We predict that internal cell wall comprised highly compressed methanochondroitin chains and we are able to identify a conceptual model for stress dependent inner cell wall growth.
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39
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Jauvert E, Palleau E, Dague E, Ressier L. Directed assembly of living Pseudomonas aeruginosa bacteria on PEI patterns generated by nanoxerography for statistical AFM bioexperiments. ACS APPLIED MATERIALS & INTERFACES 2014; 6:21230-21236. [PMID: 25434422 DOI: 10.1021/am506241n] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Immobilization of living micro-organisms on predefined areas of substrates is a prerequisite for their characterizations by atomic force microscopy (AFM) in culture media. It remains challenging since micro-organisms should not be denatured but attached strongly enough to be scanned with an AFM tip, in a liquid phase. In this work, a novel approach is proposed to electrostatically assemble biological objects of interest on 2 nm thick polyethylenimine (PEI) patterns fabricated by nanoxerography. This nanoxerography process involves electrostatic trapping of PEI chains on negatively charged patterns written on electret thin films by AFM or electrical microcontact printing. The capability of this approach is demonstrated using a common biological system, Pseudomonas aeruginosa bacteria. These negatively charged bacteria are selectively assembled on large scale arrays of PEI patterns. In contrast to other PEI continuous films commonly used for cell anchoring, these ultrathin PEI patterns strongly attached on the surface do not cause any denaturation of the assembled Pseudomonas aeruginosa bacteria. AFM characterizations of large populations of individual living bacteria in culture media can thus be easily performed through this approach, providing the opportunity to perform representative statistical data analysis. Interestingly, this process may be extended to any negatively charged micro-organism in solution.
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Affiliation(s)
- Eric Jauvert
- Université de Toulouse , LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, F-31400 Toulouse, France
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40
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Diao M, Taran E, Mahler S, Nguyen AV. A concise review of nanoscopic aspects of bioleaching bacteria-mineral interactions. Adv Colloid Interface Sci 2014; 212:45-63. [PMID: 25245273 DOI: 10.1016/j.cis.2014.08.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 08/01/2014] [Accepted: 08/28/2014] [Indexed: 01/17/2023]
Abstract
Bioleaching is a technology for the recovery of metals from minerals by means of microorganisms, which accelerate the oxidative dissolution of the mineral by regenerating ferric ions. Bioleaching processes take place at the interface of bacteria, sulfide mineral and leaching solution. The fundamental forces between a bioleaching bacterium and mineral surface are central to understanding the intricacies of interfacial phenomena, such as bacterial adhesion or detachment from minerals and the mineral dissolution. This review focuses on the current state of knowledge in the colloidal aspect of bacteria-mineral interactions, particularly for bioleaching bacteria. Special consideration is given to the microscopic structure of bacterial cells and the atomic force microscopy technique used in the quantification of fundamental interaction forces at nanoscale.
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Affiliation(s)
- Mengxue Diao
- School of Chemical Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Elena Taran
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Stephen Mahler
- School of Chemical Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia; Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Anh V Nguyen
- School of Chemical Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia.
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41
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Bando K. Mechanical Characterization of Microcapsules With Membrane Permeability by Using Indentation Analysis. J Biomech Eng 2014; 136:101003. [DOI: 10.1115/1.4028036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Accepted: 07/18/2014] [Indexed: 11/08/2022]
Abstract
Mechanical modeling of the deformation of a liquid-filled spherical microcapsule indented by a sharp truncated-cone indenter was proposed, in which membrane permeability was taken into account. The change in the internal volume of the microcapsule due to fluid permeation was calculated on the basis of Kedem and Katchalsky equations (1958, “Thermodynamic Analysis of the Permeability of Biological Membranes to Non-electrolytes,” Biochim. Biophys. Acta, 27, pp. 229–246). The membrane hydraulic permeability, membrane initial stretch, and effective osmotic pressure difference across the membrane of an alginate–poly(l)lysine–alginate (APA) microcapsule were identified by fitting calculated and measured force–displacement curves. The difference between deformed shapes with and without membrane permeability was shown, suggesting the spatial resolution of image analysis performed to measure the membrane permeability from the volume loss. The influences of changes in permeability, initial stretch, and a parameter β, used for determining the effective osmotic pressure difference, on the force–displacement relationship were examined, and mechanisms causing changes in the force–displacement relationship were discussed.
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Affiliation(s)
- Kiyoshi Bando
- Department of Mechanical Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan e-mail:
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42
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Neubauer MP, Poehlmann M, Fery A. Microcapsule mechanics: from stability to function. Adv Colloid Interface Sci 2014; 207:65-80. [PMID: 24345731 DOI: 10.1016/j.cis.2013.11.016] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 11/18/2013] [Accepted: 11/21/2013] [Indexed: 01/22/2023]
Abstract
Microcapsules are reviewed with special emphasis on the relevance of controlled mechanical properties for functional aspects. At first, assembly strategies are presented that allow control over the decisive geometrical parameters, diameter and wall thickness, which both influence the capsule's mechanical performance. As one of the most powerful approaches the layer-by-layer technique is identified. Subsequently, ensemble and, in particular, single-capsule deformation techniques are discussed. The latter generally provide more in-depth information and cover the complete range of applicable forces from smaller than pN to N. In a theory chapter, we illustrate the physics of capsule deformation. The main focus is on thin shell theory, which provides a useful approximation for many deformation scenarios. Finally, we give an overview of applications and future perspectives where the specific design of mechanical properties turns microcapsules into (multi-)functional devices, enriching especially life sciences and material sciences.
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43
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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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44
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Li Y, Wang X, Onnis-Hayden A, Wan KT, Gu AZ. Universal quantifier derived from AFM analysis links cellular mechanical properties and cell-surface integration forces with microbial deposition and transport behavior. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:1769-1778. [PMID: 24450282 DOI: 10.1021/es403511a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this study, we employed AFM analysis combined with mathematical modeling for quantifying cell-surface contact mechanics and magnitude and range of cell-surface interaction forces for seven bacterial strains with a wide range of cell morphology, dimension, and surface characteristics. Comprehensive cell-surface characterization including surface charge, extracellular polymeric substance content, hydrophobicity, and cell-cell aggregation analyses were performed. Flow-through column tests were employed to determine the attachment efficiency and deposition-transport behavior of these bacterial strains. No statistically significant correlation between attachment efficiency and any single-cell surface property was identified. Single-cell characterization by atomic force microscopy (AFM) yielded the mechanical deformation and elastic modulus, penetration resistance to AFM probe penetration by cellular surface substances (CSS), range and magnitude of the repulsive-attractive intersurface forces, and geometry of each strain. We proposed and derived a universal dimensionless modified Tabor's parameter to integrate all these properties that account for their collective behavior. Results showed that the Tabor parameter derived from AFM analysis correlated well with experimentally determined attachment efficiency (α), which therefore is able to link microscale cell-surface properties with macroscale bacterial transport behavior. Results suggested that the AFM tests performed between a single cell and a surface captured the key quantities of the interactions between the cell and the surface that dictate overall cell attachment behavior. Tabor's parameter therefore can be potentially incorporated into the microbial transport model.
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Affiliation(s)
- Yueyun Li
- Department of Civil and Environmental Engineering and ‡Department of Mechanical and Industrial Engineering, Northeastern University , Boston, Massachusetts 02115, United States
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45
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Taneja S, Levitan BA, Rutenberg AD. Circumferential gap propagation in an anisotropic elastic bacterial sacculus. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:012704. [PMID: 24580254 DOI: 10.1103/physreve.89.012704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Indexed: 06/03/2023]
Abstract
We have modeled stress concentration around small gaps in anisotropic elastic sheets, corresponding to the peptidoglycan sacculus of bacterial cells, under loading corresponding to the effects of turgor pressure in rod-shaped bacteria. We find that under normal conditions the stress concentration is insufficient to mechanically rupture bacteria, even for gaps up to a micron in length. We then explored the effects of stress-dependent smart autolysins, as hypothesized by A. L. Koch [ Adv. Microb. Physiol. 24 301 (1983); Res. Microbiol. 141 529 (1990)]. We show that the measured anisotropic elasticity of the peptidoglycan (PG) sacculus can lead to stable circumferential propagation of small gaps in the sacculus. This is consistent with the recent observation of circumferential propagation of PG-associated MreB patches in rod-shaped bacteria. We also find a bistable regime of both circumferential and axial gap propagation, which agrees with behavior reported in cytoskeletal mutants of B. subtilis. We conclude that the elastic anisotropies of a bacterial sacculus, as characterized experimentally, may be relevant for maintaining rod-shaped bacterial growth.
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Affiliation(s)
- Swadhin Taneja
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Benjamin A Levitan
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Andrew D Rutenberg
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
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46
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Pogodin S, Hasan J, Baulin VA, Webb HK, Truong VK, Phong Nguyen TH, Boshkovikj V, Fluke CJ, Watson GS, Watson JA, Crawford RJ, Ivanova EP. Biophysical model of bacterial cell interactions with nanopatterned cicada wing surfaces. Biophys J 2013; 104:835-40. [PMID: 23442962 DOI: 10.1016/j.bpj.2012.12.046] [Citation(s) in RCA: 324] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 12/03/2012] [Accepted: 12/31/2012] [Indexed: 10/27/2022] Open
Abstract
The nanopattern on the surface of Clanger cicada (Psaltoda claripennis) wings represents the first example of a new class of biomaterials that can kill bacteria on contact based solely on their physical surface structure. The wings provide a model for the development of novel functional surfaces that possess an increased resistance to bacterial contamination and infection. We propose a biophysical model of the interactions between bacterial cells and cicada wing surface structures, and show that mechanical properties, in particular cell rigidity, are key factors in determining bacterial resistance/sensitivity to the bactericidal nature of the wing surface. We confirmed this experimentally by decreasing the rigidity of surface-resistant strains through microwave irradiation of the cells, which renders them susceptible to the wing effects. Our findings demonstrate the potential benefits of incorporating cicada wing nanopatterns into the design of antibacterial nanomaterials.
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Affiliation(s)
- Sergey Pogodin
- Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Tarragona, Spain
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Destabilization induced by electropermeabilization analyzed by atomic force microscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2223-9. [PMID: 23756780 DOI: 10.1016/j.bbamem.2013.05.035] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 05/29/2013] [Accepted: 05/31/2013] [Indexed: 01/04/2023]
Abstract
Electropermeabilization is a physical method that uses electric field pulses to deliver molecules into cells and tissues. Despite its increasing interest in clinics, little is known about plasma membrane destabilization process occurring during electropermeabilization. In this work, we took advantage of atomic force microscopy to directly visualize the consequences of electropermeabilization in terms of membrane reorganization and to locally measure the membrane elasticity. We visualized transient rippling of membrane surface and measured a decrease in membrane elasticity by 40%. Our results obtained both on fixed and living CHO cells give evidence of an inner effect affecting the entire cell surface that may be related to cytoskeleton destabilization. Thus, AFM appears as a useful tool to investigate basic process of electroporation on living cells in absence of any staining or cell preparation.
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Dhahri S, Ramonda M, Marlière C. In-situ determination of the mechanical properties of gliding or non-motile bacteria by atomic force microscopy under physiological conditions without immobilization. PLoS One 2013; 8:e61663. [PMID: 23593493 PMCID: PMC3625152 DOI: 10.1371/journal.pone.0061663] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 03/12/2013] [Indexed: 11/19/2022] Open
Abstract
We present a study about AFM imaging of living, moving or self-immobilized bacteria in their genuine physiological liquid medium. No external immobilization protocol, neither chemical nor mechanical, was needed. For the first time, the native gliding movements of Gram-negative Nostoc cyanobacteria upon the surface, at speeds up to 900 µm/h, were studied by AFM. This was possible thanks to an improved combination of a gentle sample preparation process and an AFM procedure based on fast and complete force-distance curves made at every pixel, drastically reducing lateral forces. No limitation in spatial resolution or imaging rate was detected. Gram-positive and non-motile Rhodococcus wratislaviensis bacteria were studied as well. From the approach curves, Young modulus and turgor pressure were measured for both strains at different gliding speeds and are ranging from 20±3 to 105±5 MPa and 40±5 to 310±30 kPa depending on the bacterium and the gliding speed. For Nostoc, spatially limited zones with higher values of stiffness were observed. The related spatial period is much higher than the mean length of Nostoc nodules. This was explained by an inhomogeneous mechanical activation of nodules in the cyanobacterium. We also observed the presence of a soft extra cellular matrix (ECM) around the Nostoc bacterium. Both strains left a track of polymeric slime with variable thicknesses. For Rhodococcus, it is equal to few hundreds of nanometers, likely to promote its adhesion to the sample. While gliding, the Nostoc secretes a slime layer the thickness of which is in the nanometer range and increases with the gliding speed. This result reinforces the hypothesis of a propulsion mechanism based, for Nostoc cyanobacteria, on ejection of slime. These results open a large window on new studies of both dynamical phenomena of practical and fundamental interests such as the formation of biofilms and dynamic properties of bacteria in real physiological conditions.
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Affiliation(s)
- Samia Dhahri
- Géosciences Montpellier, University Montpellier 2, CNRS, Montpellier, France
| | - Michel Ramonda
- Centrale de Technologie en Micro et nanoélectronique, Laboratoire de Microscopie en Champ Proche, University Montpellier 2, Montpellier, France
| | - Christian Marlière
- Géosciences Montpellier, University Montpellier 2, CNRS, Montpellier, France
- Institut des Sciences Moléculaires d'Orsay, University Paris-Sud, CNRS, Orsay, France
- * E-mail:
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Khalilian M, Valojerdi MR, Navidbakhsh M, Chizari M, Eftekhari-Yazdi P. Estimating zona pellucida hardness under microinjection to assess oocyte/embryo quality: Analytical and experimental studies. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/abb.2013.45089] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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50
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Affiliation(s)
- Kiyoshi BANDO
- Department of Mechanical Engineering, Kansai University
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