Molecular Epidemiology and Drug Resistance of Extraintestinal Pathogenic Escherichia coli Bloodstream Isolates From Adults Worldwide (2011–2023)

BACKGROUND: Extraintestinal pathogenic Escherichia coli (ExPEC) can colonize and infect body sites outside the intestines, which can lead to invasive E. coli disease potentially resulting in sepsis or death. We evaluated O-serotype distribution, antimicrobial resistance profiles, and sequence types (STs) of ExPEC bloodstream isolates collected during 17 global surveillance studies conducted from 2011 through 2023. METHODS: E. coli clinical blood isolates from an adult population were analyzed for O-serotype, ST, and multidrug-resistance (MDR) using data obtained by agglutination, whole-genome sequencing, and determination of minimal inhibitory concentrations of antimicrobial drugs. RESULTS: Globally, 10 098 E. coli isolates were collected; 4925 (48.8%) from men and 5136 (50.9%) from women, median (range) age was 72 (18-104) years. The most prevalent ExPEC O-serotypes were O25 (18.7%), O2 (8.2%), O6 (8.2%), and O1 (7.0%). Highest MDR rates were observed in India (83.3%), Mexico (76.6%), and China (69.4%); lowest rates were in Sweden (10.6%), New Zealand (11.6%), and Netherlands (12.1%). Among MDR isolates (n=3343), serotype O25 was the most prevalent in all countries (range: 11.3% China to 56.2% Mexico). We observed a resistance rate of 1.1% and 0.7% to last-resort carbapenem and colistin antibiotics, respectively, distributed over diverse STs and O-serotypes. CONCLUSIONS: Overall, serotypes O25, O2, O6, and O1 were the most prevalent. MDR levels showed large regional variation. O25 was dominant within the subset of MDR isolates across all countries. O153-ST648, O101/O162-ST744, O102-ST405, and O25-ST131 were associated with MDR.