Evolution of extended-spectrum β-lactamase-producing ST131 Escherichia coli at a single hospital over 15 years

The study sequenced the genomes of 154 ESBL-producing E. coli clinical isolates from patients at the University of Pittsburgh Medical Center between 2004 and 2018. The most recent common ancestor for all clade C isolates emerged around 1989. Multiple genes potentially under selection in clade C were identified, and diverse mobile elements varied by ESBL type. The findings suggest that ST131 subclade C dominated among patients and suggest ongoing adaptation within this lineage.