TABLE 2.
Mean CT values of TaqMan PCR for the GIPC and analysis of variance with a post hoc Tukey's test between substratesa
| Substrate | Nb | Mean CT valuec | SD |
|---|---|---|---|
| Soil | |||
| S4O | 5 | 29.21 A | 0.93 |
| S4C | 5 | 31.31 B | 1.52 |
| S5O | 5 | 30.87 B | 0.79 |
| S5C | 5 | 30.70 B | 0.80 |
| S7O | 5 | 31.47 B | 0.14 |
| S7C | 5 | 31.92 B | 0.50 |
| S9O | 5 | 32.36 B | 1.03 |
| S9C | 5 | 31.74 B | 0.26 |
| Manure | |||
| M1 | 5 | 28.52 A | 0.70 |
| M2 | 5 | 31.64 B | 1.08 |
| M3 | 5 | 29.36 A | 0.30 |
| M4 | 5 | 29.02 A | 0.53 |
| M5 | 5 | 33.85 C | 2.05 |
| M6 | 5 | 29.01 A | 0.73 |
The GIPC was added at a concentration of 2.5 × 104 CFU/100 mg of substrate prior to DNA extraction. DNA from the soil samples was extracted using the Mobiosoil method, and DNA from the manure samples was extracted with the Bio101 method.
The total number of samples where no serovar Enteritidis (negative controls and samples below detection limit) was detected by TaqMan PCR.
Mean CT value obtained from TaqMan PCR for the GIPC. The subgroups (A, B, and C) calculated from the CT values of the GIPC using Tukey's test are indicated. The mean CT value of the soils, excluding S4O, was 31.48 ± 0.94. With soil S4O, too much (10-fold) GIPC was added to the sample prior to DNA extraction, resulting in a CT value significantly lower than that of the other soils. The mean CT value of a subset of manures (M1, M3, M4, and M6) was 28.98 ± 0.63.