All O103:H2 isolates were positive for IpfAO26, ehaA, efa1/lifA, Z2099, nleE and nleB. Conversely, none of the isolates were positive for aaiC, toxB, IpfAO113, Ipf2O157/OI-154, eibG, cnf, cdtB I–IV, nleH1–2, fyuA and pic. All STEC O103:H2 carried stx1a and none of these isolates were from cases that developed HUS. This evidence concerns the gene STX1A and hemolytic-uremic syndrome.