E. coli O157:H7 strain EDL933, which produces both Stx1 and
Stx2, was obtained from the STEC center at Michigan State University.
E. coli O157:H7 was stored in LuriaeBertani (LB) medium
containing 15% glycerol at 80 C, which was routinely grown in LB
medium at 37 C overnight with aeration. To minimize interference
of turbidity due to precipitation of medium ingredients with tannins
in GSE, Basic Media with Glucose (BMG) (Diez-Gonzalez &
Russell, 1999) was used in all experiments with GSE.