Cluster analysis of Escherichia coli isolates based on allelic profiles (A) and macroarray data (B). (A) Minimum spanning tree analysis of the 161 E. coli isolates based on allelic profiles at the eight genes dinB, icdA, pabB, polB, putP, trpA, trpB and uidA. Each circle corresponds to a sequence type (the ST number is given inside the circle), and the size of the circle is related to the number of isolates found with that profile (from 1 for small circles e.g. ST14 to 17 for ST4). Grey zones between some groups of circles indicate that these profiles belong to the same clonal complex (CC). Circles were colored based on triplex-PCR phylogroup assignment. Bold, plain and discontinuous links between circles correspond to one, two or more allelic mismatch(es), respectively; note that links with distance > 2 are not reliable (for example, the spread of group D across the entire graph does not indicate discrepancy of MLST with triplex PCR). Grey roman numbers above some CCs correspond to B2 subgroups as defined in a previous study . The position of strain APEC O1 was added manually; it corresponds to a single locus variant of ST1. (B) Classification of 60 bacteremic isolates using macroarray analysis results. Reference strains are indicated by black arrows on the right. Note that two apparently misplaced isolates (NCK023 and NCK016) belong to groups B2 and E, respectively, based on MLST genes.