Table 2. Sequence of primers used in this study.

Gene	Orientation*	Sequence (5′–3′)	Fragment size (bp)	Reference
sxt1	F	CTGGATTTAATGTCGCATAGTG	150	Guion et al. (2008)
	R	AGAACGCCCACTGAGATCATC
stx2	F	GGCACTGTCTGAAACTGCTCC	255	Guion et al. (2008)
	R	TCGCCAGTTATCTGACATTCTG
eae	F	ATGCTTAGTGCTGGTTTAGG	248	Guion et al. (2008)
	R	GCCTTCATCATTTCGCTTTC
ehxA	F	GGTGCAGCAGAAAAAGTTGTAG	1551	Schmidt et al. (1995)
	R	TCTCGCCTGATAGTGTTTGGTA
astA	F	CCATCAACACAG TAT ATCCGA	111	Yamamoto & Echeverria (1996)
	R	GGTCGCGAGTGACGGCTTTGT
chuA	F	GACGAACCA ACGGTCAGGAT	279	Clermont et al. (2000)
	R	TGCCGCCAGTACCAAAGACA
yjaA	F	TGAAGTGTCAGGAGACGCTG	211	Clermont et al. (2000)
	R	ATGGAGAATGCGTTCCTCAAC
tspE	F	GAGTAATGTCGGGGCATTCA	152	Clermont et al. (2000)
	R	CGCGCCAACAAAGTATTACG

^*F, Forward primer; R, reverse primer.