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“Background Staphylococcal enterotoxins (SEs) are extracellular proteins, produced mainly by Staphylococcus

aureus, causing food intoxication when ingested. Staphylococcal food poisoning (SFP) was the mTOR inhibitor fourth most common causative agent in food-borne illness within the EU in 2008 [1]. It is associated with food, generally rich in protein, which requires extensive manual handling, often in combination with inadequate heating and/or inappropriate storage of the food [2, 3]. To date, 21 staphylococcal enterotoxins or enterotoxin-like proteins (SEA-SEE, SEG-SEV), excluding variants, have been identified. These SE genes are widely disseminated by several mobile genetic elements leading to variations in the SE expression behavior among enterotoxigenic staphylococci [2–5]. The expression of a number of the enterotoxins including SEB, SEC, and SED is to some extent known to involve regulatory systems such as the accessory gene regulator (Agr), the staphylococcal accessory regulator (Sar) and the repressor of toxin (Rot) [6]. However, we still have limited information about SEA, the toxin considered to be mainly responsible for staphylococcal food poisoning outbreaks [7–11]. The SEA gene is carried in the bacterial genome by a polymorphic family of temperate bacteriophages [12–14]. Recent studies of S.