Gene content of Sakai phage genes and the LEE island in EHEC 2 strains. Sakai phage genes inferred as present or divergent/absent were grouped and sorted according to the Sakai annotation. Colormaps, with dendrograms, of individual phages were generated in R software (v 2.4.0.), using the 'gplots' package (v 2.3.2). Present genes are depicted as black, absent/divergent as white. Gray squares symbolize genes that have been classified as present after the cutoff was relaxed for 20%, representing a 'low' level of gene divergence. Dendrogram labels refer to strain names (Table 1). Labels with asterisks in the Sp15 and Sp5 colormaps refer to strains that were positive for stx1 and stx2 genes, respectively. Labels with open boxes in the LEE colormap represent animal strains. Arrows and numerals atop the LEE colormap represent operons and the direction of their transcription. The ECs numbers for the phage genes depicted, and the distribution of these genes, are provided in Additional file 2. Sp – Sakai prophage, SpLE – Sakai prophage-like element, TAI – tellurite resistance and adherence island.