STX2 and hemolytic-uremic syndrome: Among the 33 LEE positive STEC strains containing stx2 (Table S1 in File S1), we identified 69 genes which were overrepresented in HUS-associated strains (n = 23) and 44 genes which were more frequent in non-HUS STEC strains (n = 10) (p<0.01, data uncorrected) (Table 2, Table S4 in File S2).