Abstract:
Escherichia coli is a leading cause of community-acquired and health careassociated
bloodstream infections (BSIs) worldwide. Limited information is available regarding
the changes in population dynamics of human E. coli over extended time periods, especially
among nonbiased E. coli isolates in large well-defined geographical regions. Coque
and colleagues (I. Rodríguez, A. S. Figueiredo, M. Sousa, S. Aracil-Gisbert, et al., mSphere 6:
e00868-21, 2021, https://doi.org/10.1128/msphere.00868-21) conducted a longitudinal study
of E. coli BSIs in a Madrid hospital over a 21-year period (1996 to 2016). Certain E. coli B2
phylogroups (i.e., ST131 and ST73) dominated the community E. coli population in Madrid.
These community clones were often introduced into the hospital setting. This study and
other longitudinal surveys from England and Canada showed that ST131 subclades C1 and
C2 were mainly responsible for the increase in fluoroquinolone and cephalosporin resistance
among E. coli during the mid- to late 2000s.
