Bovine recto-anal junction squamous epithelial (RSE) cell adhesion assay for studying Escherichia coli O157 adherence.

AIM

To develop a new adherence assay, using cattle recto-anal junction squamous epithelial (RSE) cells, for evaluating bacterial adherence to cells of bovine origin.

METHODS AND RESULTS

Proof of concept was demonstrated using the human gastrointestinal pathogen Escherichia coli O157:H7, for which cattle are reservoirs. Adherence assays were conducted using both RSE and HEp-2 cells, in the presence and absence of D+Mannose. E. coli O157 specifically adhered in a type I fimbriae-independent manner to RSE cells in significantly higher numbers and also bound significantly higher numbers of RSE cells than diverse laboratory strains of nonpathogenic E. coli.

CONCLUSION

The RSE cell adhesion assay output highly reproducible and interpretable results that compared very well with those obtained using the more extensively used HEp-2 cell adherence assay.

SIGNIFICANCE AND IMPACT OF THE STUDY

The RSE cell adhesion assay provides a convenient means of directly defining and evaluating pathogen factors operating at the bovine recto-anal junction. The RSE cell adhesion assay further has the potential for extrapolation to diverse bacteria, including food-borne pathogens that colonize cattle via adherence to this particular anatomical site.