Comparative Genome Analysis of Extended-Spectrum-β-Lactamase-Producing Escherichia coli Sequence Type 131 Strains from Nepal and Japan

The global spread of ESBL- E. coli has been driven in large part by pandemic sequence type 131 (ST131). A recent study suggested that, within E. coli ST131, certain sublineages have disseminated worldwide with little association with their geographical origin, highlighting the complexity of the epidemiology of this pandemic clone. ST131 bacteria have also been classified into four virotypes based on the distribution of certain virulence genes. Information on virotype distribution in Asian ST131 strains is limited. We conducted whole-genome sequencing of ESBL- E. coli ST131 strains collected in Nepal and Japan, two Asian countries with a high and low prevalence of ESBL- E. coli , respectively. We systematically compared these ST131 genomes with those reported from other regions to gain insights into the molecular epidemiology of their spread and found the distinct phylogenetic characteristics of the spread of ESBL- E. coli ST131 in these two geographical areas of Asia.