TABLE 3.
Quantification of C. coli cells on three artificially inoculated meat pieces by three methods
| Expt(s) | Cell count obtained by indicated quantification methoda |
||
|---|---|---|---|
| qPCR | Spheroplasting-PMA-qPCR with ISPC |
Plating on mCCDA | |
| 1 | 6.59 ± 0.20 A | 6.31 ± 0.36 A | 5.44 ± 0.15 B |
| 2 | 6.57 ± 0.24 A | 5.71 ± 0.29 B | 5.64 ± 0.24 B |
| 3 | 6.60 ± 0.16 A | 5.36 ± 0.40 B | 5.92 ± 0.32 B |
| 1, 2, 3 | 6.59 ± 0.18 C | 5.79 ± 0.51 D | 5.67 ± 0.30 D |
Testing was carried out in triplicate during three independent experiments by qPCR (log10 cell equivalents per 25 cm2), spheroplasting-PMA-qPCR with ISPC (log10 cell equivalents per 25 cm2), and plating on mCCDA (log10 CFU per 25 cm2). Means with “A” or “B” after them indicate that counts were compared by ANOVA within each experiment. Means with “C” or “D” after them indicate that counts were compared by two-way ANOVA. The factors examined were experimental occasion and quantification method in all three experiments. Counts with the same letter within the same experiment are not statistically significantly different (P > 0.05) from each other, but they differ significantly (P < 0.05) from counts with a different letter.