Adhesion Forces between E. coli Bacteria and Biomaterial Surfaces

Abstract

Bacterial infection of biomaterial surfaces is an important problem in the biomedical and health industries. The design of materials resistant to infections necessitates an understanding of the forces driving bacterial adhesion. Escherichia coli cells were immobilized onto the tip of a standard atomic force microscope (AFM) cantilever, and force measurements were performed by approaching the modified cantilever onto mica, hydrophilic glass, hydrophobic glass, polystyrene, and Teflon. Consistent with prior qualitative observations, we show that bacterial adhesion is indeed enhanced by the surface hydrophobicity of the substrate. The forces of interaction measured with the AFM are compared to those of model predictions based on an extended-DLVO approach. In this model, short-range acid−base and steric interactions are included with the conventional van der Waals attraction and electrostatic components. The theoretical predictions agree well with experimental data for E. coli D21f2, a strain whose outer surface consists of lipopolysaccharide molecules with severely truncated carbohydrate chains. However, the adhesive behavior of E. coli strains with more complex cell surface structures was found to be more difficult to model because of the possible involvement of steric and bridging effects or specific receptor−ligand interactions that remain to be resolved.

Force measurements with the atomic force microscope: Technique, interpretation and applications

“…The acid-base theory also has been applied to the adhesion between cells and biological materials [386], to the adhesion between blood proteins and several functional groups [362].…”

“…First attempts in this direction were made by Razatos et al [980] who demonstrated that it is possible to coat silicon nitride AFM cantilevers including the tip with a layer of E. coli cells, if the cells were fixed by glutaraldehyde treatment. The authors took advantage of such functionalized tips to study the adhesion of E. coli [386,981] (see also Ref. [982]).…”

The effects of surface properties on Escherichia coli adhesion are modulated by shear stress

“…Bacteria often adhere to surfaces and form biological communities called biofilms [1] that develop in almost all types of biomedical devices [2]. These sessile cells are typically more resistant to antimicrobial agents than planktonic ones, have a decreased susceptibility to host defense systems and function as a source of resistant microorganisms responsible for many hospital acquired infections [3].…”

“…These sessile cells are typically more resistant to antimicrobial agents than planktonic ones, have a decreased susceptibility to host defense systems and function as a source of resistant microorganisms responsible for many hospital acquired infections [3]. Moreover, biofilm spreading on the surface upon prolonged use of the biomedical device can cause material biodegradation, changes in surface properties and deterioration of the medical functionality [1,2].…”

Adhesion of Aureobasidium pullulans Is Controlled by Uronic Acid Based Polymers and Pullulan

“…Rarely, attractive interactions have been observed, such as with Candida parapsilosis and glass, 36 with Bacillus mycoides spores and hydrophobically treated glass, 55 and glutaraldehyde-treated E. coli cells interacting with mica, glass, Teflon, or polystyrene. 56 The sources of the attractions are believed to be specific interactions between microbial macromolecules and the interacting substrate. Although such interactions would hypothetically be present in all cases, often steric repulsion is so large that it masks all such specific interactions.…”