Surface Roughness Mediated Adhesion Forces between Borosilicate Glass and Gram-Positive Bacteria

Abstract

It is well-known that a number of surface characteristics affect the extent of adhesion between two adjacent materials. One of such parameters is the surface roughness as surface asperities at the nanoscale level govern the overall adhesive forces. For example, the extent of bacterial adhesion is determined by the surface topography; also, once a bacteria colonizes a surface, proliferation of that species will take place and a biofilm may form, increasing the resistance of bacterial cells to removal. In this study, borosilicate glass was employed with varying surface roughness and coated with bovine serum albumin (BSA) in order to replicate the protein layer that covers orthopedic devices on implantation. As roughness is a scale-dependent process, relevant scan areas were analyzed using atomic force microscope (AFM) to determine Ra; furthermore, appropriate bacterial species were attached to the tip to measure the adhesion forces between cells and substrates. The bacterial species chosen (Staphylococci and Streptococci) are common pathogens associated with a number of implant related infections that are detrimental to the biomedical devices and patients. Correlation between adhesion forces and surface roughness (Ra) was generally better when the surface roughness was measured through scanned areas with size (2 × 2 μm) comparable to bacteria cells. Furthermore, the BSA coating altered the surface roughness without correlation with the initial values of such parameter; therefore, better correlations were found between adhesion forces and BSA-coated surfaces when actual surface roughness was used instead of the initial (nominal) values. It was also found that BSA induced a more hydrophilic and electron donor characteristic to the surfaces; in agreement with increasing adhesion forces of hydrophilic bacteria (as determined through microbial adhesion to solvents test) on BSA-coated substrates.

Influence of Surface Properties on Adhesion Forces and Attachment ofStreptococcus mutansto ZirconiaIn Vitro

“…According to the Derjaguin–Landau–Verwey–Overbeek (DLVO) theory [34], initial adhesion involves a number of unspecific interactions, namely, van der Waals attractive forces (vdW) and electrostatic repulsive forces. The vdW are the predominant forces while the distances between microorganism and the surface were greater than 50 nm, whereas the combination of vdW and electrostatic interactions governed the bacteria adhesion when at closer distance [35]. Our results showed that nanoscale roughness has positive effect on the S. mutans adhesion forces.…”

“…Furthermore, surface roughness is scale-dependent and can be measured in many approaches; therefore, the values of surface roughness parameters may be different at the macroscale compared to the microscale and even at the nanoscale [46]. According to Preedy et al, the correlation between surface roughness and adhesion forces varies as the size of the area is scanned to calculate roughness value [35]. …”

Effects of natural antimicrobials on bacterial cell hydrophobicity, adhesion, and zeta potential / Vpliv naravnih protimikrobnih snovi na bakterijsko hidrofobnost, adhezijo in zeta potencial

“…The first is to understand the interaction between particular bacteria and material surface (32). The second includes food as an intermediate between surface, natural antimicrobials, and bacteria in order to come up with applicable findings for food industry.…”

Evaluation of biofilm-forming ability of bacterial strains isolated from the roof of an old house

“…A high percentage of adhesion to chloroform (acid and electron acceptor solvent) was observed for most tested strains, which is superior to that for hexane (apolar solvent) and that for ethyl acetate (basic solvent and electron donor). These comparisons demonstrated the basic character and, hence, the electron donor property for most strains (Preedy et al, 2014). CRA method: The slime production of the isolates was evaluated by the Congo Red Agar method (CRA), according to the protocol of Freeman et al (1989).…”