Essential Oils as a Novel Anti-Biofilm Strategy Against Salmonella Enteritidis Isolated from Chicken Meat

<i>Salmonella</i> Enteritidis is a serious foodborne threat, being the most reported <i>Salmonella</i> serovar in the past several years. Biofilm formation contributes significantly to its persistence and resistance in food processing environments, making it harder to eliminate using conventional disinfectants. Recently, essential oils have emerged as promising natural alternatives due to their antimicrobial and anti-biofilm properties. In this study, the biofilm-forming ability of <i>Salmonella</i> Enteritidis, isolated from chicken meat, was evaluated under various nutrient conditions and temperatures. Furthermore, the anti-biofilm activity of essential oils derived from oregano, cinnamon, rosemary, clove, and thyme was assessed against strong and moderate biofilms formed by <i>Salmonella</i> Enteritidis. The isolates demonstrated the capacity to form biofilms in tryptic soy broth, meat broth, and Luria-Bertani broth at 37 °C, 15 °C, and 5 °C. All selected essential oils, at their minimum bactericidal concentrations, effectively reduced preformed biofilms by between 36.98% to 74.83%. The destructive effect of essential oils on <i>Salmonella</i> Enteritidis bacterial cells was further confirmed through scanning electron microscopy analysis. In conclusion, the selected essential oils exhibited promising anti-biofilm potential and may serve as effective natural agents for controlling biofilm-associated contamination by <i>Salmonella</i> Enteritidis.