Laboratory tests found different attachment patterns for four STEC serotypes in bovine intestinal tissue.
Four serotypes examined
A paper published on 29 August 2026 examined Shiga toxin-producing Escherichia coli, or STEC, at the bovine recto-anal junction. Researchers first characterised 71 bovine isolates and two human clinical strains, then selected O157:H7, O26:H11, O113:H21 and O130:H11 for cell and tissue tests. All four attached to primary bovine epithelial cells.
Attachment differed by tissue layer
In bovine tissue explants, O157:H7 and O26:H11 were found deeper in the layered epithelium, while O113:H21 and O130:H11 remained near the surface. The study also recorded different adhesion-related gene responses by serotype and strain. These observations came from laboratory cells and tissue explants; the paper did not test a farm intervention or measure a reduction in shedding.