Forces involved in bacterial adhesion to hydrophilic and hydrophobic surfaces

Abstract

Using a parallel-plate flow chamber, the hydrodynamic shear forces to prevent bacterial adhesion (F prev ) and to detach adhering bacteria (F det ) were evaluated for hydrophilic glass, hydrophobic, dimethyldichlorosilane (DDS)-coated glass and six different bacterial strains, in order to test the following three hypotheses. 1. A strong hydrodynamic shear force to prevent adhesion relates to a strong hydrodynamic shear force to detach an adhering organism. 2. A weak hydrodynamic shear force to detach adhering bacteria implies that more bacteria will be stimulated to detach by passing an air-liquid interface (an air bubble) through the flow chamber. 3. DLVO (Derjaguin, Landau, Verwey, Overbeek) interactions determine the characteristic hydrodynamic shear forces to prevent adhesion and to detach adhering micro-organisms as well as the detachment induced by a passing air-liquid interface. F prev varied from 0.03 to 0.70 pN, while F det varied from 0.31 to over 19.64 pN, suggesting that after initial contact, strengthening of the bond occurs. Generally, it was more difficult to detach bacteria from DDS-coated glass than from hydrophilic glass, which was confirmed by air bubble detachment studies. Calculated attractive forces based on the DLVO theory (F DLVO ) towards the secondary interaction minimum were higher on glass than on DDS-coated glass. In general, all three hypotheses had to be rejected, showing that it is important to distinguish between forces acting parallel (hydrodynamic shear) and perpendicular (DLVO, air-liquid interface passages) to the substratum surface.

Physicochemical analysis of initial adhesion and biofilm formation of Methanosarcina barkeri on polymer support material

“…Such deviations from the predictions of the DLVO model have been reported previously [24], and have been explained by the presence of microbial surface structures or chemical surface inhomogeneity [38].…”

In vitro studies of nanosilver-doped titanium implants for oral and maxillofacial surgery

“…36,37 The explanation given for this phenomenon is usually based on the simplified principles of thermodynamics related to adhesion forces calculated with the Derjaguin and Landau, Verwey, and Overbeek theory. 38 Most species of oral bacteria possess hydrophobic cell walls and can easily adhere to single-sign surfaces. However, the extensive heterogeneity of the microbial population phylotypes in the oral cavity should be taken into consideration, including their ability to switch from hydrophobic to hydrophilic properties in response to the changes in the environment.…”

Suppression effects of dental glass-ceramics with polarization-induced highly dense surface charges against bacterial adhesion

“…The amount of bacterial adhesion in this study may depend on not only an initial adhesion but also a detachment caused by wash protocol. The detachment strength of bacteria from a substrate is associated with a surface wettability 31) . Due to the hydrophilicity of polarized samples with no relation to their polar character, adhering bacteria were more readily detached from the polarized samples than from non-polarized glass-ceramics.…”