Assessing the impact of select intestinal tract conditions on expression of lee encoded genes in enterohemorrhagic escherichia

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain 86-24 accomplishes successful infection upon creating attaching and effacing (A/E) lesions on the enterocytes found in the large intestine. The A/E lesion event is possible due to the type III secretion system (T3SS) spanning the EHEC inner and outer membrane. T3SS is a molecular syringe that enables EHEC to establish trans-kingdom interactions with human and other animal hosts. The assembly and regulation of the T3SS is poorly understood. GFP reporter assay experiments showed that short chain fatty acid (SCFA) mixes representative of the large intestine increase the activity of the esp promoter that precedes the espA gene, an important component of the T3SS. Attachment data experiments showed that EspA is essential for EHEC attachment to HEp-2 epithelial cells. The data shows that biochemical cues encountered by EHEC play a role in the regulation and assembly of the T3SS ultimately leading to A/E lesion formation.