Direct Probing by Atomic Force Microscopy of the Cell Surface Softness of a Fibrillated and Nonfibrillated Oral Streptococcal Strain

Mei, Henderina van der; Busscher, Hj; Bos, Roelof; Vries, J. de; Boonaert, Christophe J. P.; Dufrêne, Yves F.

doi:10.1016/s0006-3495(00)76810-x

Cited by 82 publications

(54 citation statements)

References 18 publications

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“…The force-distance curves of the E. faecalis strains expressing Agg (Fig. 1b, d) show high adhesion forces upon retraction over a long distance, probably due to stretching of surface structures comprising the interacting groups, as corroborated by Van der Mei et al (2000) for streptococci. Comparing the force-distance curves of the E. faecalis strains expressing Agg (Fig.…”

Section: Resultsmentioning

confidence: 58%

Atomic force microscopy study on specificity and non-specificity of interaction forces between Enterococcus faecalis cells with and without aggregation substance

et al. 2005

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Enterococcus faecalis is one of the leading causes of hospital-acquired infections, and indwelling medical devices are especially prone to infection. E. faecalis expressing aggregation substance (Agg) adheres to biomaterial surfaces by means of positive cooperativity, i.e. the ability of one adhering organism to stimulate adhesion of other organisms in its immediate vicinity. In this study, atomic force microscopy (AFM) was used to measure the specificity and non-specificity of interaction forces between E. faecalis cells with and without Agg. Bacteria were attached to a substratum surface and a tip-less cantilever. Two E. faecalis strains expressing different forms of Agg showed nearly twofold higher interaction forces between bacterial cells than a strain lacking Agg [adhesive force (F adh ), "1?3 nN]. The strong interaction forces between the strains with Agg were reduced after adsorption of antibodies against Agg from "2?6 and "2?3 nN to "1?2 and "1?3 nN, respectively. This suggests that the non-specific interaction force between the enterococci amounts to approximately 1?2 nN, while the specific force component is only twofold stronger. Comparison of the results of the AFM interaction forces with the positive cooperativity after adhesion to a biomaterial in a parallel-plate flow chamber showed that in the absence of strong interaction forces between the cells, positive cooperativity was also absent. In conclusion, this is believed to be the first time that the influence of specific antibodies on interaction forces between E. faecalis cells has been demonstrated by AFM, thereby experimentally distinguishing between specific and non-specific force components.

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Section: Resultsmentioning

confidence: 58%

Atomic force microscopy study on specificity and non-specificity of interaction forces between Enterococcus faecalis cells with and without aggregation substance

et al. 2005

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“…The phase lag is produced by energy dissipation at the sample surface, which depends on material properties such as adhesion, stiffness, and viscoelasticity (Babcock and Prater, 1995;Bar et al, 2000). Although the surface properties of living bacteria and fungal spores have been studied, AFM has only recently been applied to detailed morphological investigation of bacterial spores (Chada et al, 2003;Dufrene, 2000Dufrene, , 2002Dufrene et al, 1999;Muller et al, 1996;Sokolov et al, 1996;Umeda et al, 1998;van der Mei et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

Atomic force microscopy of Bacillus spore surface morphology

Zolock¹,

Li²,

Bleckmann³

et al. 2006

Micron

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Bacillus spore surface morphology was imaged with atomic force microscopy (AFM) to determine if characteristic surface features could be used to distinguish between four closely related species; Bacillus anthracis Sterne strain, Bacillus thuringiensis var. kurstaki, Bacillus cereus strain 569, and Bacillus globigii var. niger. AFM surface height images showed an irregular topography across the curved upper surface of the spores. Phase images showed a superficial grain structure with different levels of phase contrast and significant differences in average surface morphologies among the four species. Although spores of the same species showed similarities, there was significant variability within each species. Overall, AFM revealed that spore surface morphology is rich with information, which can be used to distinguish a sample of about 20 spores from a similar number of spores of closely related species. Statistical analysis of spore morphology from a combination of amplitude and phase images for a small sample allows differentiation between, B. anthracis and its close relatives. q

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“…Emerson and Camesano (14) investigated pathogenic microbial adhesion to biomaterials by measuring the local interaction forces between an immobilized cell and both biomaterial and biofilm surfaces. Cell surface hydrophobicity and charge have also been investigated using chemically functionalized AFM probes (2,41). All of these studies and measurements provide important information on single-cell properties; nevertheless, they do not provide information on the properties of whole biofilms.…”

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confidence: 99%

Biofilm Cohesiveness Measurement Using a Novel Atomic Force Microscopy Methodology

Ahimou¹,

Semmens²,

Novak³

et al. 2007

Appl Environ Microbiol

113

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Biofilms can be undesirable, as in those covering medical implants, and beneficial, such as when they are used for waste treatment. Because cohesive strength is a primary factor affecting the balance between growth and detachment, its quantification is essential in understanding, predicting, and modeling biofilm development. In this study, we developed a novel atomic force microscopy (AFM) method for reproducibly measuring, in situ, the cohesive energy levels of moist 1-day biofilms. The biofilm was grown from an undefined mixed culture taken from activated sludge. The volume of biofilm displaced and the corresponding frictional energy dissipated were determined as a function of biofilm depth, resulting in the calculation of the cohesive energy. Our results showed that cohesive energy increased with biofilm depth, from 0.10 ؎ 0.07 nJ/m 3 to 2.05 ؎ 0.62 nJ/m 3 . This observation was reproducible, with four different biofilms showing the same behavior. Cohesive energy also increased from 0.10 ؎ 0.07 nJ/m 3 to 1.98 ؎ 0.34 nJ/m 3 when calcium (10 mM) was added to the reactor during biofilm cultivation. These results agree with previous reports on calcium increasing the cohesiveness of biofilms. This AFM-based technique can be performed with available off-the-shelf instrumentation. It could therefore be widely used to examine biofilm cohesion under a variety of conditions.It is essential to understand biofilm stability to both encourage biofilm maintenance in some applications, such as waste treatment, and effectively remove undesired biofilm in others, as in biofilms covering medical implants. Biofilm detachment is one of the critical factors that balance growth and plays a role in the development of biofilm spatial heterogeneity. While factors responsible for biofilm growth are well studied (16,29,39,42,43), those controlling the detachment process are not clearly understood (28,36,38). As a consequence, a good understanding of the relationships between operating conditions and biofilm cohesion is lacking. The cohesive strength of the biofilm is influenced by extracellular polymeric substances (EPS) and specific compounds, such as calcium, which fill the space between microbial cells and bind cells together (23,30). Understanding the cohesive interactions in the biofilm matrix under a variety of conditions could lead to the design of new strategies for controlling biofilm development based on disrupting or protecting the matrix holding the biofilm together.Because cohesive strength is a primary factor affecting biofilm sloughing, its quantification is essential in understanding detachment. A few methods based on the use of custom devices have been proposed to investigate biofilm cohesive strength. Poppele and Hozalski (31) measured the tensile strength levels of biofilms from activated sludge by using a micromechanical device based on the deflection of a glass micropipette separating a microbial aggregate held by suction. Körstgens et al. (22) used a uniaxial compression measurement device to determine the yield st...

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Direct Probing by Atomic Force Microscopy of the Cell Surface Softness of a Fibrillated and Nonfibrillated Oral Streptococcal Strain

Cited by 82 publications

References 18 publications

Atomic force microscopy study on specificity and non-specificity of interaction forces between Enterococcus faecalis cells with and without aggregation substance

Atomic force microscopy study on specificity and non-specificity of interaction forces between Enterococcus faecalis cells with and without aggregation substance

Atomic force microscopy of Bacillus spore surface morphology

Biofilm Cohesiveness Measurement Using a Novel Atomic Force Microscopy Methodology

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