Sweet cherry pomace polyphenols disrupt Salmonella enteritidis colonization on chicken skin

Salmonella Enteritidis (S. Enteritidis) is a persistent challenge within the poultry industry. The silent colonization allows S. Enteritidis establish themselves in the gut and reproductive tract, leading to persist, spread, and contaminate eggs and meat. This study investigated the anti-virulence potential of a sweet cherry pomace extract (CPE) as a potential natural decontaminant to disrupt S. Enteritidis colonization. The total phenolic content (TPC) and composition of ethanolic extracts from CPE were investigated via HPLC. Antimicrobial activities of CPE were evaluated by minimal inhibitory (MIC) and minimal bactericidal (MBC) concentrations determinations, as well as by growth kinetics and time-kill assays. Anti-virulence at sub-inhibitory concentrations (sub-MICs) was evaluated through swimming/swarming motility, biofilm formation (crystal violet), and auto-aggregation. The efficacy of CPE in reducing S. Enteritidis colonization was validated on chicken skin and visualized through scanning electron microscopy (SEM). The studied CPE was rich in phenolic compounds, predominantly anthocyanins; and exhibited an inhibitory effect against S. Enteritidis at a MIC of 64 mg/mL and MBC of 128 mg/mL. Concentrations ≤8 mg/mL did not significantly affect growth kinetics or viability. Importantly, sub-MIC levels significantly reduced swarming and swimming motility as well as biofilm formation, and auto-aggregation in a dose-dependent manner. SEM topographic analysis confirmed that CPE reduced S. Enteritidis colonization on treated chicken skin. These findings demonstrate that at sub-MICs, CPE functions as a non-bactericidal anti-virulence agent that interferes with S. Enteritidis colonization mechanisms, supporting its potential as a natural decontaminant for poultry processing.