Table 2. Primers used in this study.

Primer	Sequence	Purpose	Tm (C°)	amplicon size (bp)	References
Vt1-a	CAGTTAATGTGGTGGCGAAG	Stx1 detection	55	894	[26]
Vt1-b	CTGCTAATAGTTCTGCGCATC	Stx1 detection	55	894	[26]
Vt2-a	CTTCGGTATCCTATTCCCGG	Stx2 detection	45	478	[26]
Vt2-b	GGATGCATCTCTGGTCATTG	Stx2 detection	45	478	[26]
stx2a-F2	GCGATACTGRGBACTGTGGCC	Stx2 variant confirmedstx2a	66	349 347	[27]
stx2a-R3	CCGKCAACCTTCACTGTAAATGTG	Stx2 variant confirmedstx2a	66	349 347	[27]
stx2a-R2	GCCACCTTCACTGTGAATGTG	Stx2 variant confirmedstx2a	66	349 347	[27]
stx2b-F1	AAATATGAAGAAGATATTTGTAGCGGC	Stx2 variant confirmedstx2b	65	251	[27]
stx2b-R1	CAGCAAATCCTGAACCTGACG	Stx2 variant confirmedstx2b	65	251	[27]
stx2c-F1	GAAAGTCACAGTTTTTATATACAACGGGTA	Stx2 variant confirmed stx2c	65	177	[27]
stx2c-R2	CCGGCCACYTTTACTGTGAATGTA	Stx2 variant confirmed stx2c	65	177	[27]
stx2d-F1	AAARTCACAGTCTTTATATACAACGGGTG	Stx2 variant confirmedstx2d	65	179 235 280	[27]
stx2d-R1	TTYCCGGCCACTTTTACTGTG	Stx2 variant confirmedstx2d	65	179 235 280	[27]
stx2d-O55-R	TCAACCGAGCACTTTGCAGTAG	Stx2 variant confirmedstx2d	65	179 235 280	[27]
stx2d-R2	GCCTGATGCACAGGTACTGGAC	Stx2 variant confirmedstx2d	65	179 235 280	[27]
stx2e-F1	CGGAGTATCGGGGAGAGGC	Stx2 variant confirmedstx2e	66	411	[27]
stx2e-R2	CTTCCTGACACCTTCACAGTAAAGGT	Stx2 variant confirmedstx2e	66	411	[27]
stx2f-F1	TGGGCGTCATTCACTGGTTG	Stx2 variant confirmedstx2e	66	411	[27]
stx2f-R1	TAATGGCCGCCCTGTCTCC	Stx2 variant confirmedstx2e	66	411	[27]
stx2g-F1	CACCGGGTAGTTATATTTCTGTGGATATC	Stx2 variant detectionstx2g	62	573	[27]
stx2g-R1	GATGGCAATTCAGAATAACCGCT	Stx2 variant detectionstx2g	62	573	[27]
ECs2357f	TTAACCTTTTGTGGCGAACC	SNP ECs2357 detection	58	253	This study
ECs2357r	TACGGTTTGCCGCAGTTATT	SNP ECs2357 detection	58	253	This study
ECs2521f	CCGTAGCAGGTTCGGTAAAA	SNP ECs2521 detection	60	200	This study
ECs2521r	CGGTTCCAGTTCGTCGATAA	SNP ECs2521 detection	60	200	This study
ECs3881f	GAGAACGGCTACGCGTACAT	SNP ECs2521 detection	60	200	This study
ECs3881r	CGTTCCACACCTTTCTGGTT	SNP ECs2521 detection	60	200	This study
ECs4130f	GGGCTGCTGATTTTTGGTAT	SNP ECs4130 detection	58	229	This study
ECs4130r	CAGGCGACAGAATATCGTCA	SNP ECs4130 detection	58	229	This study
sbcB-F	GACAGCAGAAACAACGGATTTAAC	sbcB insertion site	59	406	[33]
sbcB-R2	TCCAGGCGTAAGGATCGTAG	sbcB insertion site	59	406	[33]
A	AAGTGGCGTTGCTTTGTGAT	yehV insertion site	60	340	[55]
B	AACAGATGTGTGGTGAGTGTCTG	sbcB insertion site	59	406	[33]
C	AGGAAGGTACGCATTTGACC	wrbA insertion site	60	314	[33]
D	CGAATCGCTACGGAATAGAGA	wrbA insertion site	60	314	[33]
argW-A	CCGTAACGACATGAGCAACAAG	argW insertion site	55	216	[33]
argW-D	AATTAGCCCTTAGGAGGGGC	wrbA insertion site	60	314	[33]