Draft Genome Sequences of Six Escherichia coli Isolates from the Stepwise Model of Emergence of Escherichia coli O157:H7

摘要

Enterohemorrhagic Escherichia coli (EHEC) of serotype O157:H7 has been implicated in food-borne illnesses worldwide. An evolutionary model was proposed in which the highly pathogenic EHEC O157:H7 serotype arose from its ancestor, enteropathogenic E. coli (EPEC) O55:H7 (sorbitol fermenting [SOR⁺] and β-glucuronidase positive [GUD⁺]), through sequential gain of virulence, phenotypic traits, and serotype change. Here we report six draft genomes of strains belonging to this evolutionary model: two EPEC O55:H7 (SOR⁺ GUD⁺) strains, two nonmotile EHEC O157:H⁻ strains (SOR⁺ GUD⁺) containing plasmid pSFO157, one EHEC O157:H7 (SOR⁻ GUD⁺) strain, and one O157:H7 strain containing plasmid pSFO157 (SOR⁺ GUD⁺).