title: Influence of shear on microbial adhesion to PEO-brushes and glass by convective-diffusion and sedimentation in a parallel plate flow chamber.
abstract: Microbial adhesion to surfaces often occurs despite high wall shear rates acting on the adhering microorganisms. In this paper, we compare the wall shear rates needed to prevent microbial adhesion to bare glass and poly(ethylene oxide) (PEO)-brush coated glass in a parallel plate flow chamber. Initial microbial deposition rates were determined for different wall shear rates between 4 and 1600 s(-1) on the top and bottom plates of the flow chamber. Deposition efficiencies alpha(SL), based on the Smoluchowski-Levich approach, for Pseudomonas aeruginosa D1, Escherichia coli O2K2 and Candida tropicalis GB 9/9 decreased with increasing wall shear rates and were lower for PEO-brush coated glass than for bare glass. Characteristic shear rates preventing adhesion to the bottom plate were around 10 and 1.0 s(-1) for the bacteria on glass and the PEO-brush and 36 and 3.4s(-1) for the yeast strain on glass and the PEO-brush, respectively. This demonstrates that the adhesive forces between microorganisms and a PEO-brush are comparatively weak, although some strains may have the ability to adhere to a PEO-brush under low shear conditions. Microbial deposition efficiencies alpha(SL) were much larger, however, than unity for bottom plate deposition, but could be reduced to realistic values by averaging the deposition rates found for the top (negative contribution of sedimentation) and bottom (positive contribution of sedimentation) plates.
authors.affiliation: Department of Biomedical Engineering, University Medical Center Groningen and University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
authors.forename: Astrid
authors.initials: A
authors.lastname: Roosjen
authors.forename: Niels P
authors.initials: NP
authors.lastname: Boks
authors.forename: Henny C
authors.initials: HC
authors.lastname: van der Mei
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Busscher
authors.forename: Willem
authors.initials: W
authors.lastname: Norde
mesh_terms: D001422:Bacterial Adhesion; D001672:Biocompatible Materials / Q000737:chemistry; D055592:Biophysical Phenomena; D001703:Biophysics; D041022:Candida tropicalis / Q000378:metabolism; D002448:Cell Adhesion; D003102:Colloids / Q000737:chemistry; D004058:Diffusion; D004926:Escherichia coli / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D011092:Polyethylene Glycols / Q000737:chemistry*; D011550:Pseudomonas aeruginosa / Q000378:metabolism; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors
chemical_list: D001672:Biocompatible Materials; D003102:Colloids; D011092:Polyethylene Glycols