Phylogenomic framework and virulence gene boundaries of emerging Shiga toxin-producing Escherichia coli O118 informed by the comprehensive profiling of 359 O118 genomes

. Horizontally acquired pathogenicity islands, including O-island 122 in H16 strains and a novel pathogenicity-associated island carrying antibiotic resistance, along with other loci related to colonization and interbacterial competition, further enhance their virulence potential. Our findings underscore the genetic diversity and virulence potential of O118 STEC. Understanding such phylogroup-linked virulence and resistance traits is crucial for effective surveillance and public health interventions.