Figure 2.

Phylogenetic trees for the 72 ECOR strains and six E. coli reference strains. The trees were constructed from (A) aes sequences and (B) multi-locus sequence typing of six housekeeping genes representing the species phylogeny (trpA, trpB, pabB, putP, icd and polB) [5], obtained using PHYML procedure [50]. E. fergusonii was used as an outgroup. Bootstraps are shown for values higher than 70%. Strains studied and belonging to phylogenetic groups A (blue boxed), B1 (green boxed), B2 (red boxed), D (yellow boxed) and UG (white boxed) are indicated.