TABLE 1.
Detection of EHEC-associated genetic markers in 400 raw-milk cheese samples
| Genetic markers targeted by real-time PCR (either alone or in combination with each other) | Positive samples/400 tested |
|
|---|---|---|
| No. | % | |
| Individual markers | ||
| stx | 119 | 29.8 |
| eaea | 149 | 37.3 |
| eae-β1 | 87 | 21.8 |
| eae-γ1 | 5 | 1.3 |
| eae-ɛ | 11 | 2.8 |
| eae-γ2/θ | 62 | 15.5 |
| eae-β1, eae-γ1, eae-ɛ, eae-γ2/θb | 129c | 32.3 |
| wzxO26 | 45 | 11.3 |
| wzxO103 | 95 | 23.8 |
| wbdIO111 | 1 | 0.3 |
| ihp1O145 | 183 | 45.8 |
| rfbEO157 | 20 | 5 |
| wzxO26, wzxO103, wbdIO111, ihp1O145, rfbEO157d | 221 | 55.3 |
| fliCH2 | 244 | 61.0 |
| fliCH7 | 234 | 58.5 |
| fliCH8 | 262 | 65.5 |
| fliCH11 | 197 | 49.3 |
| fliCH28 | 154 | 38.5 |
| fliCH2, fliCH7, fliCH8, fliCH11, fliCH28e | 349 | 87.3 |
| Combinations of markers | ||
| stx-eae | 68 | 17 |
| stx-wzxO26-eae | 22 | 5.5 |
| stx-wzxO26-eae-β1 | 19 | 4.8 |
| stx-wzxO26-eae-β1-fliCH11 | 19 | 4.8 |
| stx-wzxO103-eae | 31 | 7.8 |
| stx-wzxO103-eae-ɛ | 5 | 1.3 |
| stx-wzxO103-eae-ɛ-fliCH2 | 5 | 1.3 |
| stx-wbdIO111-eae | 0 | 0 |
| stx-wbdIO111-eae-γ2/θ | 0 | 0 |
| stx-ihp1O145-eae | 51 | 12.8 |
| stx-ihp1O145-eae-γ1 | 3 | 0.8 |
| stx-ihp1O145-eae-γ1-fliCH28 | 3 | 0.8 |
| stx-rfbEO157-eae | 4 | 1 |
| stx-rfbEO157-eae-γ1 | 1 | 0.3 |
| stx-rfbEO157-eae-γ1-fliCH7 | 1 | 0.3 |
| stx-(wzxO26, wzxO103, wbdIO111, ihp1O145, rfbEO157)f | 89 | 22.3 |
| stx-(wzxO26, wzxO103, wbdIO111, ihp1O145, rfbEO157)-eaeg | 61 | 15.3 |
| stx-(wzxO26, wzxO103, wbdIO111, ihp1O145, rfbEO157)-(eae-β1, eae-γ1, eae-ɛ, eae-γ2/θ)h | 54 | 13.5 |
| stx-wzxO26-eae-β1, stx-wzxO103-eae-ɛ, stx-wbdIO111-eae-γ2/θ, stx-ihp1O145-eae-γ1, stx-rfbEO157-eae-γ1i | 26j | 6.5 |
Detection of the eae gene with universal primers/probe.
Detection of at least one of the four eae variants eae-β1, eae-γ1, eae-ɛ, and eae-γ2/θ.
Twenty-two samples contained eae-β1 and eae-γ2/θ; two samples contained eae-β1 and eae-ɛ; two samples contained eae-ɛ and eae-γ2/θ; one sample contained eae-β1 and eae-γ1; two samples contained eae-β1, eae-γ2/θ, and eae-ɛ; and two samples contained eae-β1, eae-γ2/θ, and eae-γ1.
Detection of at least one of the five serogroup genetic markers wzxO26, wzxO103, wbdIO111, ihp1O145, and rfbEO157.
Detection of at least one of the five fliC alleles specific for H2, H7, H8, H11, and H28 flagellar antigens.
Detection of stx and at least one of the five serogroup genetic markers.
Detection of stx, at least one of the five serogroup genetic markers and eae.
Detection of stx, at least one of the five serogroup genetic markers, and at least one of the four eae variants.
Detection of at least one of the five stx-serogroup-eae variant marker combinations.
Two samples contained two combinations of markers each (i.e., stx-wzxO26-eae-β1 plus stx-ihp1O145-eae-γ1 and stx-ihp1O145-eae-γ1 plus stx-rfbEO157-eae-γ1).