The Molecular Basis to Escherichia Coli O157:H7 Colonisation of the Terminal Rectum in Cattle

Our research has recently defined the principle colonisation site of enterohaemorrhagic Escherichia coli O157 in cattle. EHEC O157 has a novel and exquisite tropism for the final few centimetres of the terminal rectum, proximal to the recto-anal junction. This region is characterised by a high density of lymphoid follicles. <P>
The aim of the research is to define the bacterial and host factors that are responsible for this tropism. In vitro methods will be developed that will allow both random and defined EHEC O157 mutants to be tested for loss of the tropism. This will be complemented by characterisation of this anatomical site for epithelial differences that may explain this specific and important localisation within the gastrointestinal tract.