STX1A and hemolytic-uremic syndrome: Their integrative approach, combining serotyping, stx subtyping, virulence profiling, phylogenomics, and a pangenome-wide association study (PWAS), showed that O157:H7 clade 8 strains and stx2a or stx2a + stx2c subtypes were strongly associated with HUS, while stx1a was more frequent in non-HUS cases.