Table 1.
Comparison of the stx2 fragment sequence amplified from phage DNA isolated from salad and ground beef with previously described sequences
| Sample no. | Fragment size (bp)a | stx variant(s) | Sequence homologyc | GenBank accession no. |
|---|---|---|---|---|
| Salad | ||||
| 1 | 732 | stx2, stx2c, stx2db | Escherichia coli O157:H7 00F078 | GU983682.2 |
| Stx2-converting phage 1717 | FJ188381.1 | |||
| Escherichia coli strain N5578 | GQ429168.1 | |||
| Escherichia coli strain TS06/08 | FM998848.1 | |||
| 8 | 692 | stx2, stx2c, stx2d | Escherichia coli O157:H7 00F078 | GU983682.2 |
| Stx2-converting phage 1717 | FJ188381.1 | |||
| Escherichia coli strain N5578 | GQ429168.1 | |||
| Escherichia coli strain TS06/08 | FM998848.1 | |||
| 13 | 1,211 | stx2c | Stx2-converting phage 1717 | GU983682.2 |
| Escherichia coli O157:H7 00F078 | FJ188381.1 | |||
| 17 | 725 | stx2, stx2c, stx2d | Bacteriophage A312 | AY633461.1 |
| Stx2-converting phage 1717 | FJ188381.1 | |||
| Escherichia coli O157:H7 | AB071845.1 | |||
| 19 | 521 | stx2 variant not defined | Escherichia coli OX3:H21 | L11078.1 |
| Minced beef | ||||
| 1 | 756 | stx2, stx2c, stx2d | Escherichia coli O157:H7 00F078 | GU983682.2 |
| Escherichia coli TS09/08 | FM998850.1 | |||
| Escherichia coli strain N5578 | GQ429168.1 | |||
| 5 | 1,024 | stx2 | Bacteriophage 933W | AF125520.1 |
| 6 | 1,023 | stx2 | Bacteriophage 933W | AF125520.1 |
| 11 | 498 | stx2, stx2c, stx2d | Stx2-converting phage 1717 | FJ188381.1 |
| Escherichia coli isolate P1332 | EU816442.1 | |||
| Bacteriophage A312 | AY633461.1 | |||
| 12 | 699 | stx2, stx2c, stx2d | Bacteriophage A312 | AY633461.1 |
| Stx2-converting phage 1717 | FJ188381.1 | |||
| Escherichia coli O157:H7 stx2vhdA | AB071845.1 | |||
| 14 | 740 | stx2 | Bacteriophage 933W | AF125520.1 |
| 18 | 733 | stx2 | Bacteriophage 933W | AF125520.1 |
| 25 | 705 | stx2, stx2c, stx2d, stx2g | Escherichia coli clone pEHEC400 | AY443052.1 |
| Escherichia coli strain 5021/96 | AJ567994.1 | |||
| Escherichia coli O28ab:H28 | AY095209.1 | |||
| Escherichia coli isolate EC173b serotype O174:H21 | AF500190.1 |
a
Size of the fragment sequenced and used for BLAST analysis.
b
The stx2 sequence of the fragment matches with those of all three variants.
c
Presented those sequences showing 100% homology with the sequence of the fragment and listed in the first position after BLAST analysis.