TABLE 1.

Nucleotide sequences of primers and fluorogenic probes

Primer or probea	Sequence (5′→3′)	Tm (°C)	Locationb within the target gene	Genec detected
stx1 forward	GAC TGC AAA GAC GTA TGT AGA TTC G	60	90-114	stx1 (150 bp)
stx1 reverse	ATC TAT CCC TCT GAC ATC AAC TGC	59	240-217
stx1 probe	TGA ATG TCA TTC GCT CTG CAA TAG GTA CTC	70	116-145
stx2 forward	ATT AAC CAC ACC CCA CCG	59	184-201	stx2 (200 bp)
stx2 reverse	GTC ATG GAA ACC GTT GTC AC	58	392-373
stx2 probe	CAG TTA TTT TGC TGT GGA TAT ACG AGG GCT TG	69	204-235
eae forward	GTA AGT TAC ACT ATA AAA GCA CCG TCG	59	2494-2524	O157:H7 eae (106 bp)
eae reverse	TCT GTG TGG ATG GTA ATA AAT TTT TG	59	2599-2574
eae probe	AAA TGG ACA TAG CAT CAG CAT AAT AGG CTT GCT	69	2572-2540

^aPrimers and probes were designed by using the program Primer Express version 1.0 (PE Applied Biosystems). The melting temperature (T_m) of the primers ranged from 58 to 60°C, and that of the probes ranged from 68 to 70°C. The probes were conjugated with fluorescent reporter dyes FAM 490 (stx1), HEX 530 (stx2), and Texas red 575 (eae_O157:H7) at the 5′ ends and with the quencher dye BHQ 1 for FAM and HEX and BHQ 2 for Texas red at the 3′ ends.

^bThe positions of the oligonucleotides are listed relative to the initiation codon (+1 adenine) of the respective gene.

^cThe nucleotide sequences used in the design of these primers and probes were retrieved from GenBank under accession no. M16625 (stx1), X07865 (stx2), and AF081182 (eae_O157:H7).