Abstract Description

Foodborne pathogens such as Salmonella spp., Listeria monocytogenes, and Staphylococcus aureus pose significant public health and economic risks worldwide.Recently Extracellular vesicles (EVs) derived from probiotic lactic acid bacteria (LAB) is an area of interest in research. These derived EVs show promise as natural inhibitors of foodborne pathogens. This study aims to isolate extracellular vesicles (EVs) from Lactobacillus plantarum and Lactobacillus rhamnosus during their exponential and stationary growth phases using ultracentrifugation combined with size-exclusion chromatography (SEC). These EVs were characterized by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). The antimicrobial and anti-biofilm activities of these EVs against selected foodborne pathogens were evaluated. The isolated EVs exhibited spherical morphology, with particle sizes ranging from 30 to 500 nm and concentrations between 2.6 × 10⁶ and 2.8 × 10⁹ particles/mL. EVs derived from probiotic LAB bacteria demonstrated a strong, dose-dependent antimicrobial effects, significantly inhibiting both pathogen growth and biofilm formation. EVs retained their structural intergrity after one year storage, demonstrating strong long term morphological stability. In conclusion, the probiotic-derived EVs could serve as effective anti-biofilm agents, with potential to improve the safety profile of foods. Furthermore, these EVs will potentially eliminate the viability challenge associated with incorporation of the actual probiotics into foods, to control growth of pathogens.