**Enterotoxigenic and Enterohemorrhagic** *Escherichia coli***: Survival and Modulation of Virulence in the Human Gastrointestinal Tract**

Charlène Roussel, Charlotte Cordonnier, Valérie Livrelli, Tom Van de Wiele and Stéphanie Blanquet‐Diot

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.68309

### **Abstract**

Enterotoxigenic *Escherichia coli* (ETEC) and Enterohemorrhagic *Escherichia coli* (EHEC) are major food‐ and water‐borne pathogens that constitute a serious public health threat in low‐income and developed countries, respectively. Survival and expression of viru‐ lence genes in the human digestive tract are key features in bacterial pathogenesis, but the mechanisms behind these processes remain largely unknown due to obvious pro‐ hibition of human studies. Use of well‐controlled and multi‐parametric *in vitro* models can aid in addressing knowledge gaps in ETEC and EHEC pathogenesis. After a general description of the physiopathology of ETEC and EHEC infections, this chapter will give an overview of all the *in vitro* studies that have investigated the effect of the main physi‐ cochemical and biotic parameters of the human gut on pathogen survival and expression of virulence factors. We bring a picture of how ETEC and EHEC are able to adapt to each of the successive environments of the human gastrointestinal tract by reading many cues provided by both the host and the gut microbiota.

**Keywords:** enterotoxigenic *Escherichia coli* (ETEC), enterohemorrhagic *Escherichia coli* (EHEC), survival, virulence genes expression, human gastrointestinal tract, *in vitro* models

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