Probing bacterial interactions: integrated approaches combining atomic force microscopy, electron microscopy and biophysical techniques

Ubbink, Job; Schär-Zammaretti, Prisca

doi:10.1016/j.micron.2004.11.005

Cited by 74 publications

(65 citation statements)

References 163 publications

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“…However, it has been demonstrated that the use of this method for imaging bacteria in their native state does not affect the properties of the bacterial membrane surface (28,29). Bacteria can also be imaged in an air-dried state, as this enables the high-resolution imaging of their surface morphology (28,30,31). For this reason, the bacterial cells imaged in this study were immobilized onto glass slides functionalized with PLL and allowed to air-dry.…”

Section: Journal Of Biological Chemistry 27541mentioning

confidence: 99%

Escherichia coli Cell Surface Perturbation and Disruption Induced by Antimicrobial Peptides BP100 and pepR

Alves

Melo

Franquelim

et al. 2010

Journal of Biological Chemistry

205

213

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The potential of antimicrobial peptides (AMPs) as an alternative to conventional therapies is well recognized. Insights into the biological and biophysical properties of AMPs are thus key to understanding their mode of action. In this study, the mechanisms adopted by two AMPs in disrupting the Gram-negative Escherichia coli bacterial envelope were explored. BP100 is a short cecropin A-melittin hybrid peptide known to inhibit the growth of phytopathogenic Gram-negative bacteria. pepR, on the other hand, is a novel AMP derived from the dengue virus capsid protein. Both BP100 and pepR were found to inhibit the growth of E. coli at micromolar concentrations. Zeta potential measurements of E. coli incubated with increasing peptide concentrations allowed for the establishment of a correlation between the minimal inhibitory concentration (MIC) of each AMP and membrane surface charge neutralization. While a neutralization-mediated killing mechanism adopted by either AMP is not necessarily implied, the hypothesis that surface neutralization occurs close to MIC values was confirmed. Atomic force microscopy (AFM) was then employed to visualize the structural effect of the interaction of each AMP with the E. coli cell envelope. At their MICs, BP100 and pepR progressively destroyed the bacterial envelope, with extensive damage already occurring 2 h after peptide addition to the bacteria. A similar effect was observed for each AMP in the concentration-dependent studies. At peptide concentrations below MIC values, only minor disruptions of the bacterial surface occurred.

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Section: Journal Of Biological Chemistry 27541mentioning

confidence: 99%

Escherichia coli Cell Surface Perturbation and Disruption Induced by Antimicrobial Peptides BP100 and pepR

Alves

Melo

Franquelim

et al. 2010

Journal of Biological Chemistry

205

213

View full text Add to dashboard Cite

show abstract

“…Various experimental methods have been developed to assess these properties, among which are microelectrophoresis, colloid titration, isoelectric focusing of cells, ion-exchange chromatography and surface conductivity, water contact angle measurements on cell lawns, adhesion to hydrocarbons, partitioning in aqueous two-phase systems and hydrophobic interaction chromatography (Mozes et al, 1991;Ubbink and Schar-Zammaretti, 2005). Because these assays only provide averaged information obtained on a large ensemble of cells, developing complementary tools for probing properties at the subcellular level is an important challenge.…”

Section: Imaging Living Cells and Following Dynamic Processesmentioning

confidence: 99%

“…Understanding these functions requires determination of the structural and physical properties of cell walls. Various characterization methods have been developed towards this goal (Beveridge, 1999;Beveridge and Graham, 1991;Matias and Beveridge, 2005;Ubbink and Schar-Zammaretti, 2005) -separation and chemical analysis of wall constituents, serological procedures, binding studies (dyes, antibodies and lectins), selective degradation by enzymes, cell wall mutants, modifications by antibiotics, electron microscopy techniques combined with freezefracture and surface replica or negative staining, X-ray photoelectron spectroscopy, infrared spectroscopy, contact angle and electrophoretic mobility measurements. These methods often require cell manipulation prior to examination (extraction, drying, staining) and in many cases provide averaged information obtained on a large ensemble of cells.…”

Section: Introductionmentioning

confidence: 99%

Towards a nanoscale view of fungal surfaces

Dague

Gilbert

Verbelen

et al. 2007

Yeast

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In the past years, atomic force microscopy (AFM) has offered novel possibilities for exploring the nanoscale surface properties of fungal cells. For the first time, AFM imaging enables investigators to visualize fine surface structures, such as rodlets, directly on native hydrated cells. Moreover, real-time imaging can be used to follow cell surface dynamics during cell growth and to monitor the effect of molecules such as enzymes and drugs. In fact, AFM is much more than a microscope in that when used in the force spectroscopy mode, it allows measurement of physicochemical properties such as surface energy and surface charge, to probe the elasticity of cell wall components and macromolecules, and to analyse the force and localization of molecular recognition events.

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“…AFM provides the real height profile of samples with sub-nanometer resolution. The resolution of AFM topographs surpasses optical microscopic images and is comparable to EM images (Ubbink and Schar-Zammaretti, 2005;Matsko, 2007). In addition, the process of sample preparation is far simpler than that of other microscopies.…”

Section: Introductionmentioning

confidence: 95%

Molecular imaging of membrane proteins and microfilaments using atomic force microscopy

Jung

Park

et al. 2010

Exp Mol Med

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Atomic force microscopy (AFM) is an emerging technique for a variety of uses involving the analysis of cells. AFM is widely applied to obtain information about both cellular structural and subcellular events. In particular, a variety of investigations into membrane proteins and microfilaments were performed with AFM. Here, we introduce applications of AFM to molecular imaging of membrane proteins, and various approaches for observation and identification of intracellular microfilaments at the molecular level. These approaches can contribute to many applications of AFM in cell imaging.

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Probing bacterial interactions: integrated approaches combining atomic force microscopy, electron microscopy and biophysical techniques

Cited by 74 publications

References 163 publications

Escherichia coli Cell Surface Perturbation and Disruption Induced by Antimicrobial Peptides BP100 and pepR

Escherichia coli Cell Surface Perturbation and Disruption Induced by Antimicrobial Peptides BP100 and pepR

Towards a nanoscale view of fungal surfaces

Molecular imaging of membrane proteins and microfilaments using atomic force microscopy

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