Staphylococcus aureus biofilm inhibition by high voltage prick electrostatic field (HVPEF) and the mechanism investigation

Abstract

The study was to investigate the inhibitory effect and mechanism of high voltage prick electrostatic field (HVPEF) on Staphylococcus aureus biofilms. Results showed that HVPEF effectively inactivated 24-h and 48-h established S. aureus biofilms, and the effect was verified on different food-contact materials. Confocal laser scanning microscopy and scanning electron microscopy analysis suggested that HVPEF disintegrated the established biofilms by killing the embedded bacteria, but it hardly reduced the bacteria adhesion. HVPEF also effectively inhibit the formation of S. aureus biofilms, the effects varied with electric voltage, treatment time and biofilm culture conditions. The direct effect of HVPEF on planktonic S. aureus was a possible mode of biofilm formation inhibition. HVPEF also suppressed biofilm formation by reducing the release of key compositions of extracellular polymeric substance, including extracellular DNA (eDNA), protein and polysaccharide intercellular adhesion (PIA), and regulating the expression of biofilm formation related genes (icaA, ebh, cidA, sarA, icaR and sigB). We propose HVPEF as a novel method to inhibit bacteria biofilm, based on the results, HVPEF has positive effects to prevent biofilm-associated contamination of S. aureus.