Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 21, 2014
Publication Date: N/A
Technical Abstract: Escherichia coli O157 (O157) persist at the recto-anal junction (RAJ) of gastrointestinal tracts (GIT) of cattle, the primary reservoirs of this human pathogen. We recently reported (Kudva et al., BMC Microbiol. 2012, 12: 103) that the previously identified and extensively documented principal O157 adhesins, namely, intimin and the LEE-encoded proteins have no role in the binding of this pathogen to the recto-anal junction squamous epithelial cells (RSE cells) that constitute the RAJ distally, in contrast to the central role of such proteins in facilitating adherence of O157 to the follicular epithelial cells (FAE) cells that make up the RAJ proximally. Because our observations strongly suggest that disparate mechanisms appear to contribute to O157 adherence to the histologically distinct cell-types constituting the RAJ, and also because this fact is likely to impact development of efficacious modalities to thwart O157 persistence within the bovine GIT, we undertook this study to particularly identify proteins that contribute to O157 adherence to bovine RSE cells. Specifically, we (i) defined components of the O157 proteome that interacted with the RSE-cell-surfome (complement of molecules comprising the surface of the RSE-cell) using tandem mass spectrometry (LC-MS/MS); (ii) confirmed that O157-protein components of the resultant interactome included those that contribute to O157 adherence to RSE cells but not to HEp-2 cells using adherence-inhibition assays; and (iii) generated a panel of isogenic deletion derivatives of genes encoding interesting O157 proteins identified above. We are currently evaluating the adherence of such O157 mutants to RSE cells. Results are likely to augment current knowledge for development of rational modalities for elimination of this pathogen from the GIT of bovine reservoirs.