Adhesion of Pathogenic Bacteria to Food Contact Surfaces: Influence of pH of Culture

Abstract

The adhesion ofAeromonas hydrophila, Escherichia coliO157:H7,SalmonellaEnteritidis, andStaphylococcus aureusto 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 ofA. hydrophila, E. coli,andS. aureusto both solid substrates. The attachment ofS.Enteritidis (P>.05) was not affected by the type of substrate or the culture pH, whereasE. colidisplayed 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 forS. aureus. Photomicrographs have shown that surfaces were contaminated by small clusters ofS.Enteritidis whileS. aureusinvaded the food contact surfaces in the form of small chains or cell aggregates.