Electric Field Induced Drift of Bacterial Protein Toxins of Foodborne Pathogens <i>Staphylococcus aureus</i> and <i>Escherichia coli</i> from Water

Abstract

Bacterial protein toxins secreted by foodborne pathogens, such as Staphylococcus aureus and Shiga toxin-producing Escherichia coli (STEC) strains, may cause severe toxicosis in humans if present in foods or water and constitute an important public health problem. These toxins are large biomolecules with negative and positive ions due to the ionizable groups in the residual amino acids. An innovative theoretical model of purifying aqueous flowing solutions from ionic toxins is proposed in this study. The principle of the model is based on the drift of the ionic toxins, under the application of the external electric field, towards the walls of the duct, leaving the largest part of the duct with reduced levels of toxin. Parameters, such as toxin concentration, potential and electric field intensity distributions, and surface charge densities, are studied analytically for various duct widths and various external electric fields. The proposed model succeeded to reduce toxin levels by more than 99%, for duct widths less than 1cm, making it suitable for small-scale water purification.

Keywords

• ion drift
• electric field
• staphylococcal toxin
• Shiga toxin (Stx2)