TABLE 3.
S. enterica detection by invA RNA qRT-PCR and BAM culture method in artificially contaminated produce commodities
| Food sample | Strain | Inoculation level (CFU/25 g) |
Salmonella sp. detection by the indicated method
|
DNA detection by qPCR (CT)a,b | |
|---|---|---|---|---|---|
| qRT-PCR (CT)a | BAM | ||||
| Bagged spinach | S. Enteritidis SE5 | 8 | + (27.6) | + | + (37.9) |
| S. Javiana 7N | 2 | + (28.4) | + | − | |
| Tomatoes | S. Enteritidis SE5 | 4 | + (28.7) | + | + (37.3) |
| S. Javiana 7N | 4 | + (30.1) | + | − | |
| Jalapeno peppers | S. Saintpaul 1358 H | 10 | + (33.5) | + | − |
| S. Newport 1240H | 3 | + (34.2) | + | − | |
| Serrano peppers | S. Saintpaul 50258 | 5 | + (33.9) | + | − |
| S. Newport 1240H | 3 | + (35.0) | + | − | |
a
CT values are given where the fluorescence signal was higher than the background.
b
The same RNA samples were amplified by qPCR to test for DNA contamination.