STX2 and hemolytic-uremic syndrome: Such analyses are particularly important for γ_v1 phage-containing SG8_31A strains because two of them produced a higher level of Stx2 than SG8_30 strains, and two of the four strains analysed (strain 93_161312 showing the highest level of Stx2 production and strain 53_142304 showing a modest level) were isolated from HUS patients.