title: The effect of surface properties of polycrystalline, single phase metal coatings on bacterial retention.
abstract: In the food industry microbial contamination of surfaces can result in product spoilage which may lead to potential health problems of the consumer. Surface properties can have a substantial effect on microbial retention. The surface characteristics of chemically different coatings (Cu, Ti, Mo, Ag, Fe) were defined using white light profilometry (micro-topography and surface features), atomic force microscopy (nano-topography) and physicochemical measurements. The Ag coating had the greatest topography measurements and Fe and Mo the least. Mo was the most hydrophobic coating (lowest γAB,γ(+), γ(-)) whilst Ag was the most hydrophilic (greatest γAB,γ(+), γ(-)). The physicochemical results for the Fe, Ti and Cu coatings were found to lie between those of the Ag and Mo coatings. Microbiological retention assays were carried out using Listeria monocytogenes, Escherichia coli and Staphylococcus aureus in order to determine how surface properties influenced microbial retention. It was found that surface chemistry had an effect on microbial retention, whereas the shape of the surface features and nano-topography did not. L. monocytogenes and S. aureus retention to the surfaces were mostly affected by surface micro-topography, whereas retention of E. coli to the coatings was mostly affected by the coating physicochemistry. There was no trend observed between the bacterial cell surface physicochemistry and the coating physicochemistry. This work highlights that different surface properties may be linked to factors affecting microbial retention hence, the use of surface chemistry, topography or physicochemical factors alone to describe microbial retention to a surface is no longer adequate. Moreover, the effects of surface parameters on microbial retention should be considered individually for each bacterial genus.
authors.affiliation: School of Health Care Science, Manchester Metropolitan University, Chester St, Manchester M1 5GD, UK; Surface Engineering Group, Manchester Metropolitan University, Chester St, Manchester M1 5GD, UK. Electronic address: K.A.Whitehead@mmu.ac.uk.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Whitehead
authors.affiliation: Ecole Nationale Superieure des Ingnieurs en Arts Chimiques et Technologies, 118 Route de Narbonne, 31077 Toulouse, Cedex 4, France.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Olivier
authors.affiliation: School of Health Care Science, Manchester Metropolitan University, Chester St, Manchester M1 5GD, UK.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Benson
authors.affiliation: Department of Food Science, Food Microbiology, Faculty of Science, University of Copenhagen, Denmark.
authors.forename: Nils
authors.initials: N
authors.lastname: Arneborg
authors.affiliation: School of Research Enterprise and Development, Manchester Metropolitan University, Chester St, Manchester M1 5GD, UK.
authors.forename: Joanna
authors.initials: J
authors.lastname: Verran
authors.affiliation: Surface Engineering Group, Manchester Metropolitan University, Chester St, Manchester M1 5GD, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Kelly
mesh_terms: D018407:Bacterial Physiological Phenomena; D004926:Escherichia coli / Q000502:physiology; D005525:Food-Processing Industry / Q000295:instrumentation*; D057927:Hydrophobic and Hydrophilic Interactions; D008089:Listeria monocytogenes / Q000502:physiology; D008670:Metals / Q000737:chemistry; D013211:Staphylococcus aureus / Q000502:physiology; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
chemical_list: D008670:Metals; D014025:Titanium
keywords: Bacterial retention; Chemistry; Food; Metals; Physicochemistry; Surface topography