Enterohemorrhagic isolate. Escherichia coli O157:H7 str. EC4206

Escherichia coli O157:H7. This strain is associated with Hamburger disease, which is caused by the contamination of meat products by enterohemorrhagic E. coli (EHEC). The identifier O157:H7 refers to the serotype of EHEC, and reflects the specific antigenic markers found on the surface of the cell. EHEC attaches and effaces to cells in the large intestine. There are numerous differences that distinguish O157:H7 from K-12, hundreds of them associated with genomic islands in either strain, including at least 9 large PAIs in O157:H7 that encode virulence factors. A type III secretion system, the locus of enterocyte effacement, numerous toxins and adhesins, as well as fimbrial gene clusters and iron uptake systems are found in these PAIs. Pathogenicity genes are also found on the plasmid pO157. Escherichia coli O157:H7 str. EC4206. This strain will be used for comparative analysis