Transcriptomic insights into species-specific responses of Staphylococcus aureus and Vibrio parahaemolyticus biofilms to acidic electrolyzed water on blueberries and oysters.

Abstract

Foodborne pathogens and their biofilms seriously endanger global fresh food safety, and conventional non-thermal disinfection is limited by poor biofilm removal capacity. However, the species-specific mechanisms against biofilm-embedded pathogens and the matrix-dependent efficacy on real food surfaces have not been systematically investigated for AEW. Herein, the disinfection efficiency and molecular mechanisms of residue-free acidic electrolyzed water (AEW) were explored against Staphylococcus aureus (Gram-positive) and Vibrio parahaemolyticus (Gram-negative). AEW achieved full bacterial inactivation within 30 s and showed no evidence of inducing stable inherited resistance over 10 successive generations. In practical food matrices, AEW eliminated pathogens on blueberries in 1 min, whereas over 3 min was needed for rough-shelled oysters, and mature biofilms, especially of S. aureus displayed stronger tolerance, which was further quantified via the Weibull kinetic model. Transcriptomic changes in quorum sensing, two-component, and metabolic pathways were consistent with increased reactive oxygen species (ROS) levels and biofilm disruption observed physiologically and ultrastructurally, suggesting that AEW may impair biofilm integrity and contribute to metabolic suppression in a species-dependent manner, without evident membrane lysis.With its fast disinfection and zero-residue features, AEW shows application potential for on-site decontamination of fruits and seafood in food industry.