FIG 1.

Genetic relatedness in representative ESBL E. coli isolates from Chicago children. Isolates in which band patterns demonstrated >95% similarity (Pearson's correlation) were considered to be clonal and of the same strain type. Phylogroup, phylogenetic group; ESBL, extended-spectrum β-lactamase; MLST, multilocus sequence type, Pasteur scheme. ST43 is equivalent to ST131 on the Achtman's scheme. MLST was performed on select isolates from rep-PCR strain types. The CTX-M-1 group of note contains CTX-M-15, associated with the pandemic CTX-M type ESBL in E. coli. The CTX-M-9 group of note contains CTX-M-9 and CTX-M-14, the second most common circulating CTX-M type ESBL. LC 157 is a novel ST type.