TABLE 3.
Association of phage 2851 genes in wild-type E. coli O157: H7 strains
| stx2c genea | stx gene | Total no. of strains | Origin (no. of strains from indicated origin) | No. of strains positive in PCR forb:
|
|||||
|---|---|---|---|---|---|---|---|---|---|
| q2851 | o2851 | int2851 | attL2851 | attR2851 | ospB2851 | ||||
| Negative | Negative | 8 | Germany (6), The Netherlands (2) | 0 | 0 | 0 | 0 | 0 | 0 |
| stx2 | 21 | Germany (20), United States (1) | 0 | 0 | 0 | 0 | 0 | 1 | |
| stx1 + stx2 | 14 | United States (9), Canada (3), United Kingdom (1), Germany (1) | 0 | 1 | 0 | 0 | 0 | 2 | |
| Total negative | 43 | 0 | 1 | 0 | 0 | 0 | 3 | ||
| Positive | stx2c | 4 | Germany (4)c | 3 | 3 | 3 | 3 | 3 | 3 |
| stx1 + stx2c | 27 | Germany (26), United States (1) | 27 | 25 | 27 | 27 | 27 | 27 | |
| stx2 + stx2c | 8 | United States (1), Denmark (2), United Kingdom (1), Germany (4) | 8 | 7 | 8 | 8 | 8 | 8 | |
| Total positive | 39 | 38 | 36 | 38 | 38 | 38 | 38 | ||
a
stx2c gene determined by PCR using primers 94 and 95.
b
Diagnostic PCRs were for the following genes of phage 2851 (Table 2 shows primers and RFLP): q2851, q antiterminator gene of phage 2851; o2851, o replication gene; int2851, integrase gene; attL2851 and attR2851, left and right integration loci (attachment sites), respectively, of phage 2851; and ospB2851, gene for putative type III effector.
c
Strain CB8028 (urease positive) was negative for all phage 2851 sequences.