Cell culture
The non-transformed continuous cell line IPEC-1, isolated from the small intestine of an unsuckled, newborn piglet [32] was used as a model for porcine small intestinal epithelium. The cells were cultured in Dulbecco’s modified eagle medium/Ham’s F12 Nutrient Mixture (DMEM/Ham’s F-12 [1:1]) supplemented with 5% fetal calf serum (FCS), 1% insulin-transferrin-selenium (ITS), 16 mmol/L HEPES (all PAN-Biotech, Germany) and 5 ng/mL epidermal growth factor (EGF; BD, Franklin Lakes, New Jersey) at 39°C and 5% CO2. In the adhesion and adhesion inhibition experiments, the cells were seeded at a density of 2 x 105 /ml to a Transwell-like culture (Thincerts™, 1 μm pore size, diameter 10 mm; Greiner bio-one, Frickenhausen, Germany) and cultured for 4–5 days to allow differentiation, until the transepithelial electric resistance (TEER) value was ≥1 kΩcm2.