TABLE 1.
Detection of virulence genes in E. coli ONT:H25 and O157:H25 strains by PCR
| Genea | Primers (5′ to 3′) and fragment size (reference)b | Gene detected in:
|
||||
|---|---|---|---|---|---|---|
|
E. coli ONT:H25c
|
E. coli O157d
|
|||||
| SH1 | SH2 | SH3 | W1 | W2 | ||
| eaeA | F, GTGGCGAATACTGGCGAGACT | + | + | + | + | + |
| R, CCCCATTCTTTTTCACCGTCG | ||||||
| 890 bp (20) | ||||||
| stx1 | F, ACACTGGATGATCTCAGTGG | − | − | − | + | + |
| R, CTGAATCCCCCTCCATTATG | ||||||
| 614 bp (21) | ||||||
| stx2 | F, CCATGACAACGGACAGCAGTT | + | + | + | + | + |
| R, CCTGTCAACTGAGCA(GCA)CTTTG | ||||||
| 779 bp (21) | ||||||
| tir | F, CATTACCTTCACAAACCGAC | + | + | + | + | + |
| R, CCCCGTTAATCCTCCCAT | ||||||
| 1550 bp (29) | ||||||
| hylA | F, ACGATGTGGTTTATTCTGGA | + | + | + | + | + |
| R, CTTCACGTGACCATACATAT | ||||||
| 165 bp (19) | ||||||
| fliCh7 | F, GCGCTGTCGAGTTCTATCGAGC | − | − | − | + | + |
| R, CAACGGTGACTTTATCGCCATTCC | ||||||
| 625 bp (25) | ||||||
a
eaeA, stx1, stx2, tir, hlyA, and fliCh7 refer to the genes which encode intimin, Shiga toxin type 1, Shiga toxin type 2, translocated intimin receptor, EHEC-hemolysin, and H7 flagellar antigen, respectively.
b
F, forward primer; R, reverse primer. Predicted size of amplified product is indicated in bases; the corresponding reference is indicated in parentheses.
c
Three strains of E. coli ONT:H25 isolated in this study, designated as SH1, SH2, and SH3. One hundred percent of 258 individual isolates representing these strains gave identical results.
d
Two different E. coli strains isolated in this study, designated as W1 and W2.