Fig. 4

a NcoI restriction site maps of the chromosomes from FRIK804 (outer), FRIK1275 (middle), and FRIK1625 (inner). An alignment and comparison of farm X strains detected the presence of two indels which distinguished each strain. The identity of each indel was determined using the nucleotide sequence of FRIK804. The location of indel-3 was consistent with the absence of the stx2-prophage in FRIK1625. Indel-4 was determined to overlap portions of two adjacent prophage, Φ804–9 and Φ804–10. b Hierarchical clustering and pairwise alignment scoring of NcoI chromosome restriction maps was used to assess relative similarity of the three farm X strains with 30 other E. coli. EHEC O157:H7 strains grouped together (black), and farm X strains (underlined) formed a cluster (bold), indicating that these strains were closely related to one another. FRIK966 is a lineage group II strain included for comparative purposes