scholarly journals Effect of glutaraldehyde fixation on bacterial cells observed by atomic force microscopy

Scanning ◽  
2011 ◽  
Vol 34 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Bao You Liu ◽  
Guang Min Zhang ◽  
Xue Ling Li ◽  
Heng Chen
Keyword(s):  
Atomic Force Microscopy ◽  
Bacterial Cells ◽  
Glutaraldehyde Fixation ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Atomic force microscopy recognition of protein A onStaphylococcus aureuscell surfaces by labelling with IgG–Au conjugates

2013 ◽  
Vol 4 ◽  
pp. 743-749 ◽  
Author(s):  
Elena B Tatlybaeva ◽  
Hike N Nikiyan ◽  
Alexey S Vasilchenko ◽  
Dmitri G Deryabin
Keyword(s):  
Atomic Force Microscopy ◽  
Protein A ◽  
Bacterial Cells ◽  
Force Microscopy ◽  
Selective Labelling ◽  
Atomic Force ◽  
Novel Approach ◽  
Preferential Binding ◽  
Igg Receptors ◽  
Labelling Method

The labelling of functional molecules on the surface of bacterial cells is one way to recognize the bacteria. In this work, we have developed a method for the selective labelling of protein A on the cell surfaces ofStaphylococcus aureusby using nanosized immunogold conjugates as cell-surface markers for atomic force microscopy (AFM). The use of 30-nm size Au nanoparticles conjugated with immunoglobulin G (IgG) allowed the visualization, localization and distribution of protein A–IgG complexes on the surface ofS. aureus. The selectivity of the labelling method was confirmed in mixtures ofS. aureuswithBacillus licheniformiscells, which differed by size and shape and had no IgG receptors on the surface. A preferential binding of the IgG–Au conjugates toS. aureuswas obtained. Thus, this novel approach allows the identification of protein A and other IgG receptor-bearing bacteria, which is useful for AFM indication of pathogenic microorganisms in poly-component associations.

Interaction of Bacterial Cells with Cluster-Assembled Nanostructured Titania Surfaces: An Atomic Force Microscopy Study

2013 ◽  
Vol 13 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Ajay Vikram Singh ◽  
Massimilano Galluzzi ◽  
Francesca Borghi ◽  
Marco Indrieri ◽  
Varun Vyas ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Microscopy Study ◽  
Bacterial Cells ◽  
Atomic Force Microscopy Study ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nanostructured Titania

scholarly journals Novel Combination of Atomic Force Microscopy and Epifluorescence Microscopy for Visualization of Leaching Bacteria on Pyrite

2007 ◽  
Vol 74 (2) ◽  
pp. 410-415 ◽  
Author(s):  
Stefanie Mangold ◽  
Kerstin Harneit ◽  
Thore Rohwerder ◽  
Günter Claus ◽  
Wolfgang Sand
Keyword(s):  
Atomic Force Microscopy ◽  
Extracellular Polymeric Substances ◽  
Metal Sulfide ◽  
Epifluorescence Microscopy ◽  
Bacterial Cells ◽  
Cell Integrity ◽  
Force Microscopy ◽  
Topographic Features ◽  
Atomic Force ◽  
Leaching Bacteria

ABSTRACT Bioleaching of metal sulfides is an interfacial process comprising the interactions of attached bacterial cells and bacterial extracellular polymeric substances with the surface of a mineral sulfide. Such processes and the associated biofilms can be investigated at high spatial resolution using atomic force microscopy (AFM). Therefore, we visualized biofilms of the meso-acidophilic leaching bacterium Acidithiobacillus ferrooxidans strain A2 on the metal sulfide pyrite with a newly developed combination of AFM with epifluorescence microscopy (EFM). This novel system allowed the imaging of the same sample location with both instruments. The pyrite sample, as fixed on a shuttle stage, was transferred between AFM and EFM devices. By staining the bacterial DNA with a specific fluorescence dye, bacterial cells were labeled and could easily be distinguished from other topographic features occurring in the AFM image. AFM scanning in liquid caused deformation and detachment of cells, but scanning in air had no effect on cell integrity. In summary, we successfully demonstrate that the new microscopic system was applicable for visualizing bioleaching samples. Moreover, the combination of AFM and EFM in general seems to be a powerful tool for investigations of biofilms on opaque materials and will help to advance our knowledge of biological interfacial processes. In principle, the shuttle stage can be transferred to additional instruments, and combinations of AFM and EFM with other surface-analyzing devices can be proposed.

scholarly journals Surface Viscoelasticity of Individual Gram-Negative Bacterial Cells Measured Using Atomic Force Microscopy

2008 ◽  
Vol 190 (12) ◽  
pp. 4225-4232 ◽  
Author(s):  
Virginia Vadillo-Rodriguez ◽  
Terry J. Beveridge ◽  
John R. Dutcher
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Cell Surface ◽  
Cell Envelope ◽  
Compressive Force ◽  
Bacterial Cells ◽  
Gram Negative ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cell Surface Structure

ABSTRACT The cell envelope of gram-negative bacteria is responsible for many important biological functions: it plays a structural role, it accommodates the selective transfer of material across the cell wall, it undergoes changes made necessary by growth and division, and it transfers information about the environment into the cell. Thus, an accurate quantification of cell mechanical properties is required not only to understand physiological processes but also to help elucidate the relationship between cell surface structure and function. We have used a novel, atomic force microscopy (AFM)-based approach to probe the mechanical properties of single bacterial cells by applying a constant compressive force to the cell under fluid conditions while measuring the time-dependent displacement (creep) of the AFM tip due to the viscoelastic properties of the cell. For these experiments, we chose a representative gram-negative bacterium, Pseudomonas aeruginosa PAO1, and we used regular V-shaped AFM cantilevers with pyramid-shaped and colloidal tips. We find that the cell response is well described by a three-element mechanical model which describes an effective cell spring constant, k 1, and an effective time constant, τ, for the creep deformation. Adding glutaraldehyde, an agent that increases the covalent bonding of the cell surface, produced a significant increase in k 1 together with a significant decrease in τ. This work represents a new attempt toward the understanding of the nanomechanical properties of single bacteria while they are under fluid conditions, which could be of practical value for elucidating, for instance, the biomechanical effects of drugs (such as antibiotics) on pathogens.

Atomic Force Microscopy Studies of the Interaction of Antimicrobial Peptides with Bacterial Cells

2017 ◽  
Vol 70 (2) ◽  
pp. 130 ◽  
Author(s):  
Anna Mularski ◽  
Frances Separovic
Keyword(s):  
Atomic Force Microscopy ◽  
Antimicrobial Peptides ◽  
Turgor Pressure ◽  
Living Cells ◽  
Bacterial Cells ◽  
Diverse Range ◽  
Bacterial Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Conventional Antibiotics

Antimicrobial peptides (AMPs) are promising therapeutic alternatives to conventional antibiotics. Many AMPs are membrane-active but their mode of action in killing bacteria or in inhibiting their growth remains elusive. Recent studies indicate the mechanism of action depends on peptide structure and lipid components of the bacterial cell membrane. Owing to the complexity of working with living cells, most of these studies have been conducted with synthetic membrane systems, which neglect the possible role of bacterial surface structures in these interactions. In recent years, atomic force microscopy has been utilized to study a diverse range of biological systems under non-destructive, physiologically relevant conditions that yield in situ biophysical measurements of living cells. This approach has been applied to the study of AMP interaction with bacterial cells, generating data that describe how the peptides modulate various biophysical behaviours of individual bacteria, including the turgor pressure, cell wall elasticity, bacterial capsule thickness, and organization of bacterial adhesins.

scholarly journals SSNOMBACTER: A collection of scattering-type scanning near-field optical microscopy and atomic force microscopy images of bacterial cells

GigaScience ◽  
2020 ◽  
Vol 9 (11) ◽  
Author(s):  
Massimiliano Lucidi ◽  
Denis E Tranca ◽  
Lorenzo Nichele ◽  
Devrim Ünay ◽  
George A Stanciu ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Optical Microscopy ◽  
Imaging Techniques ◽  
Near Field ◽  
Bacterial Species ◽  
Life Sciences ◽  
Bacterial Cells ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Images

Abstract Background In recent years, a variety of imaging techniques operating at nanoscale resolution have been reported. These techniques have the potential to enrich our understanding of bacterial species relevant to human health, such as antibiotic-resistant pathogens. However, owing to the novelty of these techniques, their use is still confined to addressing very particular applications, and their availability is limited owing to associated costs and required expertise. Among these, scattering-type scanning near field optical microscopy (s-SNOM) has been demonstrated as a powerful tool for exploring important optical properties at nanoscale resolution, depending only on the size of a sharp tip. Despite its huge potential to resolve aspects that cannot be tackled otherwise, the penetration of s-SNOM into the life sciences is still proceeding at a slow pace for the aforementioned reasons. Results In this work we introduce SSNOMBACTER, a set of s-SNOM images collected on 15 bacterial species. These come accompanied by registered Atomic Force Microscopy images, which are useful for placing nanoscale optical information in a relevant topographic context. Conclusions The proposed dataset aims to augment the popularity of s-SNOM and for accelerating its penetration in life sciences. Furthermore, we consider this dataset to be useful for the development and benchmarking of image analysis tools dedicated to s-SNOM imaging, which are scarce, despite the high need. In this latter context we discuss a series of image processing and analysis applications where SSNOMBACTER could be of help.

Sign in / Sign up

Export Citation Format

Share Document