Table 3 Percentage of nucleotide sequence identity of cdt genes between selected strains and type strains

cnf2 -positive CTEC-V

Bv-1

OUT:H1

B1

cdt-V ¹ (99.8%)/cdt-III ² (98.0%)

cdt-VA (100%)/cdt-IIIA (97.3%)

cdt-IIIB (100%)/cdt-VB (99.9%)

cdt-VC (99.3%)/cdt-IIIC (96.2%)

Bv-3

O8:HUT

B1

Bv-5

OUT:H2

B1

Bv-8

OUT:H2

B1

Bv-15

OUT:H2

B1

Bv-49

OUT:H2

B1

Bv-65

OUT:H2

B1

CTEC-V with untypable cdt genes by previous PCRs

Bv-55

OUT:H48

D

cdt-V (97.1%)/cdt-III (95.9%)

cdt-VA (96.4%)/cdt-IIIA (94.6%)

cdt-IIIB (97.0%)/cdt-VB (96.9%)

cdt-VC (98.4%)/cdt-IIIC (96.0%)

Bv-68

OUT:H48

D

Sw-26

O98:H10

B1

cdt-V (95.8%)/cdt-III (95.1%)

SbcdtA ³ (94.5%)/EacdtA ⁴ (94.2%)

cdt-IIIB (99.1%)/cdt-VB (99.0%)

cdt-VC (97.4%)/cdt-IIIC (95.1%)

CTEC-III and V

Bv-87 (cdt-III)

O2:HUT

B2

cdt-III (98.7%)/cdt-V (97.6%)

cdt-IIIA (97.6%)/cdt-VA (95.1%)

cdt-IIIB (100%)/cdt-VB (99.9%)

cdt-IIIC (98.5%)/cdt-VC (97.6%)

Bv-87 (cdt-V)

cdt-V (98.3%)/cdt-III (97.1%)

cdt-VA (96.5%)/cdt-IIIA (94.7%)

cdt-IIIB (99.8%)/cdt-VB (99.6%)

cdt-VC (98.7%)/cdt-IIIC (96.3%)

Randomly selected 9 strains from CTEC-V

Bv-7

O22:HUT

B1

cdt-V (100%)/cdt-III (98.0%)

cdt-VA (100%)/cdt-IIIA (97.3%)

cdt-VB (100%)/cdt-IIIB (99.9%)

cdt-VC (100%)/cdt-IIIC (96.2%)

Bv-43

O154:H34

B1

Bv-56

O156:HUT

B1

Bv-61

OUT:H8

B1

Bv-91

O22:H8

B1

Bv-98

O22:H8

B1

Bv-21

O2:H10

B2

cdt-V (99.8%)/cdt-III (98.1%)

cdt-VA (100%)/cdt-IIIA (97.3%)

cdt-IIIB (99.9%)/cdt-VB (99.8%)

cdt-VC (99.5%)/cdt-IIIC (96.7%)

Bv-88

OUT:H25

B1

cdt-V (99.8%)/cdt-III (98.0%)

cdt-VA (100%)/cdt-IIIA (97.3%)

cdt-IIIB (100%)/cdt-VB (99.9%)

cdt-VC (99.3%)/cdt-IIIC (96.2%)

Bv-100

OUT:H21

B1

cdt-V (99.7%)/cdt-III (98.0%)

cdt-VA (99.9%)/cdt-IIIA (97.2%)

cdt-IIIB (99.9%)/cdt-VB (99.8%)

cdt-VC (99.5%)/cdt-IIIC (96.3%)