%0 Journal Article
%T Adhesion of Pathogenic Bacteria to Food Contact Surfaces: Influence of pH of Culture
%A Akier Assanta Mafu
%A Corinne Plumety
%A Louise Desch¨ºnes
%A Jacques Goulet
%J International Journal of Microbiology
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/972494
%X The adhesion of Aeromonas hydrophila, Escherichia coli O157:H7, Salmonella Enteritidis, and Staphylococcus aureus to hydrophobic and hydrophilic surfaces in cultures with different pHs (6, 7, and 8) was studied. The results indicated that the type of material had no effect on the attachment capacity of microorganisms, while environmental pH influenced the adhesion of A. hydrophila, E. coli, and S. aureus to both solid substrates. The attachment of S. Enteritidis ( ) was not affected by the type of substrate or the culture pH, whereas E. coli displayed the weakest affinity for both polystyrene and glass surfaces. No correlation was established between the physicochemical properties of the materials, or the bacterial and the rate of bacterial adhesion, except for S. aureus. Photomicrographs have shown that surfaces were contaminated by small clusters of S. Enteritidis while S. aureus invaded the food contact surfaces in the form of small chains or cell aggregates. 1. Introduction In food processing plants, residues of all kinds chemical, biological, organic, or inorganic inevitably accumulate on the surfaces of equipments in contact with food [1]. Attachment of undesirable microorganisms to these surfaces is a source of concern, since this can result in product contamination leading to serious economic and health problems [2¨C4]. In fact, this microbial contamination has two components: first, the saprophytic flora responsible for food spoilage and second, the pathogenic flora, which cause infections in humans and animals. To adversely affect the sensory, physical, and chemical qualities of food, a large population of spoilage-causing microorganisms is required, while in the case of food pathogens it only takes a few cells to affect product safety and cause food poisoning. In the phenomenon of bacterial adhesion to inert surfaces, the physicochemical properties (hydrophobicity and charges) and substrates or surface topography are playing important roles [5¨C7]. Joints such as valves and any other difficult-to-reach spaces are the most favourable areas to bacterial adhesion. The effect of corrosion on solid materials must also be considered since it can lead to the formation and expansion of cavities and grooves [8]. This in turn provides breeding sites for microorganisms, thereby compromising the efficacy of cleaning and disinfection procedures. The surface characteristics of the microorganisms themselves and the various environmental conditions encountered in agri-food industries (organic materials, pH, temperature, water activity, etc.) also influence
%U http://www.hindawi.com/journals/ijmicro/2011/972494/