Fig. 1. Rifampicin-resisant E.coli 0157:H7 adhered/attached to stainless steel and high-density polyethylene (HDPE)coupons submerged in inoculated (six-strain mixture of rifampicin-resistant E.coli0157:H7;6log CFU/ml or g)trypic soy broth(TSB),fat-lean homogenate and ground beef,and stored at 4 and 15c for 168h.