E. Coli Genomes Contribute to Year-Long Surveillance Effort in US Healthcare Network

In Genome Medicine, a research team at the Walter Reed Army Institute of Research's Multidrug-Resistant Organism Repository and Surveillance Network and the Walter Reed National Military Medical Center's pathology department present findings from an Escherichia coli epidemiology study centered on clinical isolates collected from patients treated through a tertiary healthcare network. Using a combination of whole-genome sequencing, phylogenetics, antibiotic susceptibility testing, and analyses of available clinical data, the team assessed 2,075 E. coli isolates from almost 1,800 patients treated from October 2019 to the following September, highlighting apparent transmission clusters involving clones with and without multidrug resistant (MDR) features. Across the isolates tested, the authors found MDR features in 27 percent, with 5 percent of the bugs containing an extended-spectrum beta-lactamase gene linked to beta-lactam antibiotic resistance. "By coupling in-depth genomic characterization with a complete sampling of clinical isolates for a full year, this study provides a rare and contemporary survey on the epidemiology and spread of E. coli in a large US healthcare network," they write, adding that "our findings reveal that non-MDR isolates represent a large burden of infections, including those of predicted nosocomial origins."