biostudies-literatureUnknown8(7)Ogura Y<h4>Background</h4>Enterohemorrhagic Escherichia coli (EHEC) O157 causes severe food-borne illness in humans. The chromosome of O157 consists of 4.1 Mb backbone sequences shared by benign E. coli K-12, and 1.4 Mb O157-specific sequences encoding many virulence determinants, such as Shiga toxin genes (stx genes) and the locus of enterocyte effacement (LEE). Non-O157 EHECs belonging to distinct clonal lineages from O157 also cause similar illness in humans. According to the 'parallel' evolution model, they have independently acquired the major virulence determinants, the stx genes and LEE. However, the genomic differences between O157 and non-O157 EHECs have not yet been systematically analyzed.<h4>Results</h4>Using microarray and whole genome PCR scanning analyses, we performed a whole genoGenome biologyR138https://www.ebi.ac.uk/biostudies/studies/S-EPMC2323221biostudies-literatureExtensive genomic diversity and selective conservation of virulence-determinants in enterohemorrhagic Escherichia coli strains of O157 and non-O157 serotypes.PMC2323221Tashiro KOswald EHayashi TTerajima JOgura YKuhara STobe TOoka TNougayrede JPWatanabe HKurokawa KAsadulghaniNakayama KfalseExtensive genomic diversity and selective conservation of virulence-determinants in enterohemorrhagic Escherichia coli strains of O157 and non-O157 serotypes.<h4>Background</h4>Enterohemorrhagic Escherichia coli (EHEC) O157 causes severe food-borne illness in humans. The chromosome of O157 consists of 4.1 Mb backbone sequences shared by benign E. coli K-12, and 1.4 Mb O157-specific sequences encoding many virulence determinants, such as Shiga toxin genes (stx genes) and the locus of enterocyte effacement (LEE). Non-O157 EHECs belonging to distinct clonal lineages from O157 also cause similar illness in humans. According to the 'parallel' evolution model, they have independently acquired the major virulence determinants, the stx genes and LEE. However, the genomic differences between O157 and non-O157 EHECs have not yet been systematically analyzed.<h4>Results</h4>Using microarray and whole genome PCR scanning analyses, we performed a whole geno2007-01-01T00:00:00Z20072026-05-02T17:17:24.155Z2026-04-07T18:14:15.118ZS-EPMC23232211771159610.1186/gb-2007-8-7-r138