Figure 9

Histogram of the differences in genomic G+C content between the E. coli type strain and the other 250 strains contained in the data set. In accordance to a within-species difference of at most 1% in the G+C content [26], none of the differences between the distinct strains of E. coli are above that threshold. The G+C differences to E. hermannii NBRC 105704 (3.4%, “A”) and Shimwellia blattae DSM 4481 (5.9%, “B”) are considerably larger, whereas E. albertii, E. fergusonii and “Escherichia sp. TW09308” (which are also phylogenetically more close to E. coli; see Figure 6 and Figure 7) cannot be distinguished from E. coli using the G+C content.