scholarly journals Effect of Alginate Lyase on Biofilm-GrownHelicobacter pyloriProbed by Atomic Force Microscopy

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Alessandro Maiorana ◽  
Francesca Bugli ◽  
Massimiliano Papi ◽  
Riccardo Torelli ◽  
Gabriele Ciasca ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Extracellular Polymeric Substances ◽  
Alginate Lyase ◽  
Adhesion Properties ◽  
Force Microscopy ◽  
Coccoid Form ◽  
Atomic Force ◽  
Biofilm Architecture ◽  
H Pylori ◽  
New Strategies

Helicobacter pylori(H. pylori) is a microorganism with a pronounced capability of adaptation under environmental stress solicitations. Its persistence and antimicrobial resistance to the drugs commonly used in the anti-H. pyloritherapy are associated with the development of a biofilm mainly composed of DNA, proteins, and polysaccharides. A fundamental step to increase the success of clinical treatments is the development of new strategies and molecules able to interfere with the biofilm architecture and thus able to enhance the effects of antibiotics. By using Atomic Force Microscopy and Scanning Electron Microscopy we analyzed the effects of the alginate lyase (AlgL), an enzyme able to degrade a wide class of polysaccharides, on theH. pylorishape, surface morphology, and biofilm adhesion properties. We demonstrated that AlgL generates a noticeable loss ofH. pyloricoccoid form in favor of the bacillary form and reduces theH. pyloriextracellular polymeric substances (EPS).

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 Nanoscale characterization of effect of l-arginine on Streptococcus mutans biofilm adhesion by atomic force microscopy

Microbiology ◽  
2014 ◽  
Vol 160 (7) ◽  
pp. 1466-1473 ◽  
Author(s):  
Shivani Sharma ◽  
Stacey Lavender ◽  
JungReem Woo ◽  
Lihong Guo ◽  
Wenyuan Shi ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Atomic Force Microscopy ◽  
Streptococcus Mutans ◽  
Oral Microbiome ◽  
Aetiological Factor ◽  
Tooth Surface ◽  
Extracellular Polysaccharides ◽  
Adhesion Properties ◽  
Force Microscopy ◽  
Atomic Force

A major aetiological factor of dental caries is the pathology of the dental plaque biofilms. The amino acid l-arginine (Arg) is found naturally in saliva as a free molecule or as a part of salivary peptides and proteins. Plaque bacteria metabolize Arg to produce alkali and neutralize glycolytic acids, promoting a less cariogenous oral microbiome. Here, we explored an alternative and complementary mechanism of action of Arg using atomic force microscopy. The nanomechanical properties of Streptococcus mutans biofilm extracellular matrix were characterized under physiological buffer conditions. We report the effect of Arg on the adhesive behaviour and structural properties of extracellular polysaccharides in S. mutans biofilms. High-resolution imaging of biofilm surfaces can reveal additional structural information on bacterial cells embedded within the surrounding extracellular matrix. A dense extracellular matrix was observed in biofilms without Arg compared to those grown in the presence of Arg. S. mutans biofilms grown in the presence of Arg could influence the production and/or composition of extracellular membrane glucans and thereby affect their adhesion properties. Our results suggest that the presence of Arg in the oral cavity could influence the adhesion properties of S. mutans to the tooth surface.

scholarly journals The role of polymers in cross-kingdom bioadhesion

2019 ◽  
Vol 374 (1784) ◽  
pp. 20190192 ◽  
Author(s):  
A. L. Morales-García ◽  
R. G. Bailey ◽  
S. Jana ◽  
J. G. Burgess
Keyword(s):  
Atomic Force Microscopy ◽  
Extracellular Polymeric Substances ◽  
Cell Counting ◽  
Extracellular Matrices ◽  
Medical Applications ◽  
Theme Issue ◽  
Force Microscopy ◽  
Atomic Force ◽  
Evolutionary Advantage

The secretion of extracellular polymeric substances provides an evolutionary advantage found in many organisms that can adhere to surfaces and cover themselves in a protective matrix. This ability is found in prokaryotes, archaea and eukaryotes, all of which use functionally similar polysaccharides, proteins and nucleic acids to form extracellular matrices, mucus and bioadhesive substances. These macromolecules have been investigated from the perspective of polymer biophysics, and theories to help understand adhesion, viscosity and gelling have been developed. These properties can be measured experimentally using straightforward methods such as cell counting as well as more advanced techniques such as atomic force microscopy and rheometry. An integrated understanding of the properties and uses of adhesive macromolecules across kingdoms is also important and can provide the basis for a range of biotechnological and medical applications. This article is part of the theme issue ‘Transdisciplinary approaches to the study of adhesion and adhesives in biological systems’.

In vivonanoscale atomic force microscopy investigation of diatom adhesion properties

2002 ◽  
Vol 18 (7) ◽  
pp. 763-766 ◽  
Author(s):  
I. C. Gebeshuber ◽  
J. B. Thompson ◽  
Y. Del Amo ◽  
H. Stachelberger ◽  
J. H. Kindt
Keyword(s):  
Atomic Force Microscopy ◽  
Adhesion Properties ◽  
Force Microscopy ◽  
Atomic Force Microscopy Investigation ◽  
Atomic Force ◽  
Microscopy Investigation

Biofilm Formation and Extracellular Polymeric Substances (EPS) Analysis by New Isolates of Leptospirillum, Acidithiobacillus and Sulfobacillus from Armenia

2015 ◽  
Vol 1130 ◽  
pp. 153-156 ◽  
Author(s):  
Arevik K. Vardanyan ◽  
Narine S. Vardanyan ◽  
Levon Markosyan ◽  
Wolfgang Sand ◽  
Mario Vera ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Epifluorescence Microscopy ◽  
Sulfide Ores ◽  
Uronic Acids ◽  
Force Microscopy ◽  
Atomic Force

Biofilm formation by new isolates, Leptospirillum sp. strain ZC, Acidithiobacillus sp. strain 61 and Sulfobacillus sp. strain 6 isolated from different biotopes of sulfide ores in Armenia on pyrite was studied by atomic force microscopy (AFM) combined with epifluorescence microscopy (EFM). It was revealed that all the tested species formed monolayer biofilms The results showed that in contrast to Acidithiobacillus sp. strain 61 and Sulfobacillus sp. strain 6, cells of Leptospirillum sp. strain ZC were often observed by clusters and aggregates.The composition of capsular and colloidal EPS formed by isolated Leptospirillum sp. strain ZC, Acidithiobacillus sp. strain 61 and Sulfobacillus sp. strain 6 was studied. It was revealed that the EPS of all three species grown on iron (II) mainly consisted of carbohydrates, proteins as well as uronic acids.

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