Open reading frames that distinguish the two clonal complexes CC1 and CC4 from other Escherichia coli isolates. Pattern of presence (yellow) or absence (blue) of ORFs, which presence was positively (A) or negatively (B) associated with B2 isolates of CC1 and/or CC4 isolates, as compared with non-CC1, non-CC4 B2 isolates. Each row corresponds to one ORF; columns represent the 26 assayed B2 isolates grouped by clonal complex. Blue: absent; yellow: present; black: inconclusive. Note that ORFs are clustered vertically using software TMeV based on their pattern of presence among isolates. Five groups can be distinguished based on presence/absence in CC1 and/or CC4, as commented on the right. In panel A), colored squares on the right indicate that ORFs belong to genomic clusters (see text), as indicated.