Fig. 2

Phylogeny of ST131 isolates from study participants. a Mid-point rooted maximum likelihood tree based on the core genome of 297 ST131 isolates from 17 participants and the reference E. coli NCTC13441 genome after removal of MGEs and recombination events. The inner ring provides a link between each isolate genome and the participant from which this was cultured. The outer ring shows the presence of bla _CTX-M-15, expression of which results in an ESBL phenotype. Grey shaded blocks highlight three clades of closely related isolates from multiple participants. Red triangles indicate nodes with bootstrap values of more than 90%. b, c, d Isolates from P10, P22 and P12, respectively