TABLE 4.
Accessory virulence factors in non-O157 isolates positive for any VT2 gene included in this study
| Origin of isolates | Virulence factor | No. of isolates positive for virulence factor/no. of isolates tested (%)
|
χ2 | P | |
|---|---|---|---|---|---|
| With VT2d gene | Without VT2d gene | ||||
| Human | eaeA | 0/44 (0) | 16/46 (35) | 16.31 | 0.000054 |
| EHEC plasmid | 8/44 (18) | 21/46 (46) | 6.56 | 0.010 | |
| Enterohemolysin | 16/44 (36) | 21/46 (46) | 0.46 | NSa | |
| Animal | eaeA | 0/21 (0) | 1/32 (3) | NAb | NS |
| EHEC plasmid | 2/21 (10) | 6/32 (19) | NA | NS | |
| Enterohemolysin | 6/21 (29) | 10/32 (31) | NA | NS | |
a
NS, not significant.
b
NA, not applicable; the expected value was less than 5. The Fisher exact test was used to determine the P value.