Adherence and cytotoxicity of E. coli hybrid strains to intestinal epithelial cells. The representative adherent phenotype (A) and adherence rate (B) of 6 E. coli hybrid isolates on porcine intestinal epithelial J2 cells (IPEC-J2) cells at 3 h after challenge are presented. Enterotoxigenic E. coli (CVCC 225), enteropathogenic E. coli (CVCC1450) and Shiga toxin-producing E. coli (CICC 10670) were used as positive controls, and PBS (CONT) was used as a negative control. The release of LDH was measured in supernatant collected from the indicated IPEC-J2 cell cultures at 3 h after E. coli challenge. The monolayers were washed, fixed, and stained with Giemsa. Scale bars, 100 µm. Data are presented as the mean ± SEM of 3 independent experiments.