A comparative study of the molecular characteristics of human uropathogenic Escherichia coli collected from two hospitals in Norway and France in 2019.

BACKGROUND

Escherichia coli is the primary aetiological agent of urinary tract infections (UTIs), a frequent cause of antibiotic prescription. Over the years, E. coli has become increasingly resistant towards several antimicrobial drugs used to treat UTIs.

OBJECTIVES

To compare the population structures and antimicrobial resistance profiles by molecular characterization of longitudinally collected E. coli from urine samples at two university hospitals in Norway and France.

METHOD

Each month in 2019, the first 10 E. coli identified in urine cultures of hospitalized and primary healthcare (PHC) patients were collected at both locations. WGS was performed to detect acquired antimicrobial resistance genes (ARGs) and plasmids and to determine phylogenetic relationships between isolates.

RESULTS

A total of 478 isolates were included, revealing a high diversity of STs among the isolates. However, the same 10 STs (ST73, ST131, ST69, ST95, ST12, ST141, ST127, ST10, ST58 and ST404) were dominant in both countries, constituting 55.9% (n = 267) of all isolates. Seven of the 10 prevalent STs belonged to phylogroup B2. The number of ARGs varied from 0 (n = 229) to 17 (n = 2). The mean ARG was higher in the French (2.9) than in the Norwegian cohort (2.1, P < 0.001), as well as in the hospitalized (3.0) compared with the PHC cohort (2.0, P = 0.007).

CONCLUSIONS

Despite the differences in patterns of ARGs between the Norwegian and French cohorts, the E. coli population structure was surprisingly highly conserved, suggesting that the distribution of the most common lineages largely depends on factors other than antibiotic use and resistance.