Genotypic Characteristics and Antimicrobial Resistance of Escherichia coli ST141 Clonal Group

Escherichia coli ST141 is one of the ExPEC lineages whose incidence is rising in France, even if no epidemic situation involving multidrug resistant isolates has been reported so far. Nonetheless, in a 2015-2017 monocentric study conducted in our French University hospital, ST141 was the most frequent lineage after ST131 in our collection of phylogroup B2 ESBL-producing E. coli. The genomes of 187 isolates representing ST141 group, including 170 genomes from public databases and 17 from our local collection, of which 13 produced ESBL, were analyzed to infer the maximum likelihood phylogeny SNP-based (Single Nucleotide Polymorphism) free-recombinant tree defining the ST141 population structure. Genomes were screened for genes encoding virulence factors (VFs) and antimicrobial resistance (AMR). We also evaluated the distribution of isolates according to their origin (host, disease, country) and the distribution of VFs or AMR genes. Finally, the phylogenic tree revealed that ST141 isolates clustered into two main sublineages, with low genetic diversity. Contrasting with a highly virulent profile, as many isolates accumulated VFs, the prevalence of AMR was limited, with no evidence of multidrug resistant emerging lineage. However, our results suggest that surveillance of this clonal group, which has the potential to spread widely in the community, would be essential.

Automated summary

Escherichia coli ST141 is a clonal group that is increasingly prevalent in France, although no epidemic of multidrug-resistant isolates has been reported. In a study conducted in a French University hospital, ST141 was the second most common lineage after ST131 among ESBL-producing E. coli isolates. The genetic analysis of 187 ST141 isolates revealed a low genetic diversity and two main sublineages. While many isolates had a highly virulent profile, the prevalence of antimicrobial resistance was limited. Nevertheless, surveillance of this clonal group is important due to its potential for wide community spread.