The collected samples of each product were prepared according to American Public Health Association (APHA). Preparation of samples, decimal dilutions, and culturing techniques for EHEC was performed according to the methods described by the APHA . Briefly, 25 mL/g from each sample was aseptically transferred into a sterile polyethylene stomacher bag and blended with 225 mL of sterile buffered peptone water (Cat. #610098, LIOFILCHEM, Italy) in a stomacher (Stomacher 400, Seaward Medicals, UK) at 230 rpm for 1 min. Serial dilutions were made using sterile 0.1% peptone water.