Bacterial Adhesion at Synthetic Surfaces

Abstract

A systematic investigation into the effect of surface chemistry on bacterial adhesion was carried out. In particular, a number of physicochemical factors important in defining the surface at the molecular level were assessed for their effect on the adhesion ofListeria monocytogenes, Salmonella typhimurium,Staphylococcus aureus, and Escherichia coli. The primary experiments involved the grafting of groups varying in hydrophilicity, hydrophobicity, chain length, and chemical functionality onto glass substrates such that the surfaces were homogeneous and densely packed with functional groups. All of the surfaces were found to be chemically well defined, and their measured surface energies varied from 15 to 41 mJ · m−2. Protein adsorption experiments were performed with3H-labelled bovine serum albumin and cytochromec prior to bacterial attachment studies. Hydrophilic uncharged surfaces showed the greatest resistance to protein adsorption; however, our studies also showed that the effectiveness of poly(ethyleneoxide) (PEO) polymers was not simply a result of its hydrophilicity and molecular weight alone. The adsorption of the two proteins approximately correlated with short-term cell adhesion, and bacterial attachment for L. monocytogenes and E. coli also correlated with the chemistry of the underlying substrate. However, for S. aureus and S. typhimurium a different pattern of attachment occurred, suggesting a dissimilar mechanism of cell attachment, although high-molecular-weight PEO was still the least-cell-adsorbing surface. The implications of this for in vivo attachment of cells suggest that hydrophilic passivating groups may be the best method for preventing cell adsorption to synthetic substrates provided they can be grafted uniformly and in sufficient density at the surface.

In vitroevaluation of the mucin-adhesion ability and probiotic potential ofLactobacillus mucosaeLM1

“…On the other hand, for inhibition via displacement, receptor affinity of the adhesins is also important aside from overall adhesion, such as the way beta-linked galactose is essential for recognition by the E. coli K88ac adhesin (Grange et al 1998). Cunliffe et al (1999) also showed that S. Typhimurium may use a different mode of cell attachment compared to E. coli. In their study, hydropathy did not have an effect on S. Typhimurium attachment, suggesting the presence of adhesion-promoting substances that allows binding to both hydrophobic and hydrophilic substrates.…”

Surface Sampling and the Detection of Contamination

“…Recovery rates can vary from 0.1% to 25% (Moore and Griffith, 2007) and will depend on the technique used but an optimum recovery rate of 10% for Dacron swabs is not uncommon. The type and number of microorganisms sampled can have a major effect on recovery (Rose et al, 2011;Downey et al, 2012) and they can become increasingly difficult to remove once they have adhered to a surface (Cunliffe et al, 1999), particularly in biofilms. Additionally, organism retention within the bud fibers results in poor repeatability and sensitivity.…”

One-Step, Painting-Like Coating Procedures To Make Surfaces Highly and Permanently Bactericidal

“…Solutions. Yeast-dextrose broth contained (per L of deionized water) 10 g of peptone, 8 g of beef extract, 5 g of NaCl, 5 g of glucose, and 3 g of yeast extract (10). Phosphate-buffered saline (PBS) contained (per L of deionized water) 8.2 g of NaCl and 1.2 g of NaH 2 PO 4 ‚H 2 O.…”