Table 1. Phenotypic and genotypic characteristics of O157:non-H7 and O157:H7 strains used in this study.
| Strain | Year | Sora | GUDb | O157c | rfbE | H typed | fliC-H typee | stx1 | stx2 | ehxA | eae | eae typef | tir | bfpA | astA | irp2 |
| O157:non-H7 | ||||||||||||||||
| EC95-42 | 1995 | + | + | + | + | H45 | H45 | − | − | − | + | α | + | + | + | − |
| PV51 | 1996 | + | + | + | + | H45 | H45 | − | − | − | + | α | + | + | + | − |
| PV52 | 1996 | + | + | + | + | H45 | H45 | − | − | − | + | α | + | + | + | − |
| PV405 | 1997 | + | + | + | + | H45 | H45 | − | − | − | + | α | + | + | + | − |
| PV00-100 | 2000 | − | + | + | + | H16 | H16 | − | − | − | − | − | − | − | − | − |
| PV276 | 1997 | − | + | + | + | NM | H16 | − | − | − | − | − | − | − | − | − |
| PV284 | 1997 | − | + | + | + | NM | H16 | − | − | − | − | − | − | − | − | − |
| PV325 | 1997 | − | + | + | + | NM | H16 | − | − | − | − | − | − | − | − | − |
| PV06-4 | 2006 | − | + | + | + | NM | H16 | − | − | − | − | − | − | − | − | − |
| PV807 | 1999 | + | + | + | + | H16 | H16 | − | − | − | + | ε | + | − | − | − |
| PV01-185 | 2001 | + | + | + | + | H16 | H16 | − | − | − | + | ε | + | − | − | − |
| PV01-276 | 2001 | + | + | + | + | H16 | H16 | − | − | − | + | ε | + | − | − | − |
| PV02-85 | 2002 | + | + | + | + | H16 | H16 | − | − | − | + | ε | + | − | − | − |
| PV56 | 1996 | + | + | + | + | H39 | H39 | − | − | − | + | κ | + | − | − | − |
| PV57 | 1996 | + | + | + | + | H39 | H39 | − | − | − | + | κ | + | − | − | − |
| PV193 | 1996 | + | + | + | + | H39 | H39 | − | − | − | + | κ | + | − | − | − |
| PV00-24 | 2000 | + | + | + | + | H43 | UT | − | − | − | − | − | − | − | − | − |
| PV05-43 | 2005 | + | + | + | + | NM | H10 | − | − | − | − | − | − | − | − | − |
| PV01-182 | 2001 | + | + | + | + | UT | UT | − | − | − | − | − | − | − | − | − |
| PV01-183 | 2001 | + | + | + | + | UT | UT | − | − | − | − | − | − | − | − | − |
| PV496 | 1998 | + | + | + | + | UT | UT | − | − | − | − | − | − | − | − | + |
| O157:H7 | ||||||||||||||||
| Sakai | 1996 | − | − | + | + | H7 | H7 | + | + | + | + | γ | + | − | − | − |
| ATCC43895 | 1982 | − | − | + | + | H7 | H7 | + | + | + | + | γ | + | − | − | − |
| ATCC43888 | − | − | + | + | H7 | H7 | − | − | + | + | γ | + | − | − | − |
a
Sor, Sorbitol fermentation.
b
GUD, β-glucuronidase activity.
c
O-serogroup detected by the E. coli O157-specific antibody.
d
H-serogroup detected by the E. coli H-specific antibodies. NM; non-motile, UT; untypeable.
e
genotype detected by the PCR-RFLP assay of the fliC gene. UT; untypeable.
f
genotype detected by the PCR assay of the eae gene.