Synergistic antibacterial effect of DNase I and eugenol against Salmonella Enteritidis biofilm on smoked duck and food contact surfaces

Salmonella Enteritidis is one of the major pathogens causing food poisoning worldwide. The persistent nature of this pathogen causes significant food safety and sanitization challenges. As an alternative and efficient approach, the present study investigated the effect of DNase I and eugenol to control S. Enteritidis biofilm formation on stainless steel (SS), polyethylene terephthalate (PET), and smoked duck surfaces. Individual DNase I and eugenol treatments showed biofilm reductions of >1 and 1.9 log CFU/Cm2 on SS surfaces within 2 h, respectively. However, the combined DNase I and eugenol treatment resulted in 4.4 log biofilm reduction of S. Enteritidis wild cocktail on PET and SS surfaces, respectively, within 30 min, which was significantly higher than the individual treatments (p < 0.05). Biofilm reductions on PET and smoked duck surfaces were visually confirmed with field emission scanning electron microscopy. The quality of the smoked duck remained unaffected after subsequent treatments. In addition, 100 μg/mL of DNase and 0.36% of eugenol significantly (p < 0.05) suppressed the quorum sensing (luxS) and stress response regulation (rpoS) genes. Hence, the study suggests that co-treatment with DNase I and eugenol could be a promising approach to control S. Enteritidis biofilms and minimize related health risks from the duck processing plant.