TABLE 4.
Performance criteria of PCR assays
| PCR assay | Criterion | Value for strain (bont type) |
|||||
|---|---|---|---|---|---|---|---|
| Stockholm (C) | BKT015925 (C/D) | Eklund (C/D) | 1873 (D) | D-4947 (D) | 1585-19-11 (D/C) | ||
| C. novyi sensu lato | Efficiency (%)a | 94 | 97 | 96 | 103 | 81 | 87 |
| R2b | 0.9935 | 0.9973 | 0.9942 | 0.9937 | 0.9936 | 0.9972 | |
| Slopec | −3.47 | −3.40 | −3.42 | −3.25 | −3.88 | −3.68 | |
| LOD (fg)d | 10 | 100 | 100 | 20 | 100 | 10 | |
| Genome eq.e | 3 | 30 | 30 | 6 | 30 | 3 | |
| ntnh_grpIII | Efficiency (%) | 116 | 106 | 104 | 118 | 99 | 106 |
| R2 | 0.9962 | 0.9953 | 0.9962 | 0.9964 | 1.0000 | 0.9957 | |
| Slope | −2.99 | −3.19 | −3.23 | −2.95 | −3.35 | −3.19 | |
| LOD (fg) | 100 | 100 | 100 | 20 | 100 | 10 | |
| Genome eq. | 30 | 30 | 30 | 6 | 30 | 3 | |
| fliC-I | Efficiency (%) | 115 | |||||
| R2 | 0.9998 | ||||||
| Slope | −3.01 | ||||||
| LOD (fg) | 100 | ||||||
| Genome eq. | 30 | ||||||
| fliC-II | Efficiency (%) | 90 | 103 | ||||
| R2 | 0.9780 | 0.9958 | |||||
| Slope | −3.59 | −3.25 | |||||
| LOD (fg) | 10 | 20 | |||||
| Genome eq. | 3 | 6 | |||||
| fliC-III | Efficiency (%) | 92 | |||||
| R2 | 0.9885 | ||||||
| Slope | −3.53 | ||||||
| LOD (fg) | 100 | ||||||
| Genome eq. | 30 | ||||||
| fliC-IV | Efficiency (%) | 107 | |||||
| R2 | 0.9938 | ||||||
| Slope | −3.16 | ||||||
| LOD (fg) | 10 | ||||||
| Genome eq. | 3 | ||||||
| fliC-V | Efficiency (%) | 98 | |||||
| R2 | 0.9952 | ||||||
| Slope | −3.37 | ||||||
| LOD (fg) | 20 | ||||||
| Genome eq. | 6 | ||||||
a
Efficiency was calculated based on the following formula: E = −1 + 10−1/slope.
b
R2, regression correlation coefficient.
c
The slope of the linearity curve was calculated based on log dilution plotted against their corresponding threshold cycles (CT).
d
LOD, limit of detection.
e
Genome equivalents (eq.) were calculated according to each genome size on the assumption that the average mass of a base pair is 650 Da, using the website http://cels.uri.edu/gsc/cndna.html.