Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2016
Publication Date: N/A
Technical Abstract: Escherichia coli O157:H7 (O157) was the first Shiga toxin-producing E. coli serotype to be associated with bloody diarrhea or hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS) in humans. It has since been implicated in several outbreaks in the U.S. and globally. Non-O157 STEC have not been associated with major outbreaks but still cause 64 percent of all STEC infections in the U.S. Cattle are well documented ruminant reservoirs of STEC, and the primary site of STEC persistence in these animals is the rectoanal junction (RAJ). To investigate this persistence at the RAJ we have (i) analyzed O157 adherence at a histological level, (ii) developed a novel adherence assay using squamous epithelial cells at the RAJ, (iii) evaluated the role of well characterized STEC adherence proteins, in STEC attachment to the RAJ, and (iv) explored the similarities in RAJ-STEC interactions with another ruminant animal. STEC show distinct adherence patterns on the columnar epithelial and squamous epithelial (RSE) cells at the RAJ. The novel RSE cell adhesion assay provides a convenient means of directly evaluating bacterial interactions with host-specific cells. We have determined that proteins other than LEE and intimin-gamma proteins are involved in STEC adherence to RSE cells. Such proteins, with adhesin potential, have been shortlisted using proteomics for development of efficacious anti-adhesion modalities. We have also found that bison and cattle RAJ share similar distribution of epithelial cell markers and O157 adheres to RSE cells from both animals in similar patterns, supporting bison as likely 'wildlife' reservoirs for O157.