TABLE 2.
Detection and isolation of E. coli O157 by PCR, immunoassay, and immunocapture techniques
| Inoculum level (CFU) | Detection of E. coli O157 in raw milk enriched witha:
|
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| mTSB−n
|
mTSB+n
|
|||||||||
| Screening
|
Isolation
|
Screening
|
Isolation
|
|||||||
| rfb PCR | VIP | Tecra VIA | Dynabeads | Tecra immunocapture | rfb PCR | VIP | Tecra VIA | Dynabeads | Tecra immunocapture | |
| CL-8 (uninoculated) | − | − | − | − | − | − | NT | − | − | − |
| 1.3 × 103 | + | + | + | + | + | + | + | + | + | + |
| 1.3 × 102 | + | NT | + | + | + | + | + | + | + | + |
| 13 | + | + | + | + | + | + | + | + | + | + |
| 1 | − | − | − | − | − | + | + | + | + | + |
| <1 | − | − | − | − | − | + | + | + | − | + |
| EC200 (uninoculated) | − | − | − | − | − | − | − | − | − | − |
| 1.3 × 103 | + | − | − | − | + | + | + | + | − | + |
| 1.3 × 102 | + | − | − | − | − | + | − | − | − | + |
| 13 | + | − | − | − | − | + | − | − | − | + |
| 1 | − | NT | − | − | − | + | − | − | − | + |
| <1 | − | NT | − | − | − | − | − | − | − | − |
a
−, E. coli O157 undetected; +, E. coli O157 detected; NT, not tested.