Foodborne diseases caused by pathogens pose a great threat to human health. According to the Center for Disease Control and Prevention (CDC), foodborne diseases are caused by Salmonella spp., Clostridium perfringens, Campylobacter spp., and Staphylococcus aureus, the most common microorganisms found in food eaten in the United States [1]. Most foodborne pathogens can form biofilms on various surfaces, such as stainless steel, glass, polyurethane, and rubber [2,3]. Biofilms formed by foodborne pathogens have become a major problem in meat, dairy, and fish processing, as well as in the ready-to-eat (RTE) food industry. Biofilm formation is an important factor in the cross-contamination and persistence of foodborne pathogens [4]. It is difficult to remove foodborne pathogens once they form biofilms because biofilm cells are more resistant to antimicrobial agents and sanitizing treatments than planktonic cells [5]. Biofilms are surrounded by extracellular polymeric substances, which are composed of exopolysaccharides (EPS), proteins, lipids, and extracellular DNA [6]. Extracellular polymeric substances protect bacterial cells from the effects of antimicrobial agents and assist in retaining the structural integrity of the biofilm. S. aureus is a major foodborne pathogen that causes 241,148 illnesses per year [7] and forms biofilms on food and food contact surfaces [8]. Moreover, biofilm formation by S. aureus plays a crucial role in staphylococcal infections by protecting the colony from the host immune system and antimicrobial treatment [9]. Therefore, the prevention of S. aureus biofilm formation has become important for countering foodborne staphylococcal outbreaks. Since antibiotics are limited in their ability to inhibit S. aureus biofilms, many studies on natural antimicrobial agents and compounds produced using probiotics have been performed [10-13]. For example, some natural preservatives, such as grapefruit seed extract (GSE), have been used together with antimicrobial and anti-biofilm agents against Gram-positive and Gram-negative bacteria [14]. Moreover, some probiotics consisting of lactic acid bacteria have been reported to inhibit biofilm formation by Listeria monocytogenes [4], Pseudomonas aeruginosa [15], Bacillus licheniformis [16], Vibrio spp. [17], and methicillin-resistant S. aureus (MRSA) [18]. Saccharomyces cerevisiae has been reported that the probiotic yeast isolated from fermented food such as kefir, wine, and cucumber jangajji (Korean fermented food) [19,20]. The positive effects of S. cerevisiae, including antioxidant, anti-inflammatory, toxin eradication, and antagonistic activities, have been investigated [21-23]. In particular, the supernatant and lysate of S. cerevisiae cultures exerted an anti-biofilm effect against S. aureus, as demonstrated by the expression of the α-hemolysin and enterotoxin A genes (hla and sea). However, the effects of S. cerevisiae on the cell surface characteristics, EPS production, and expression of biofilm-related genes in S. aureus have not yet been investigat...
