Table 5. Specificity evaluation of the two immunotests: Blind testing of supernatants from different Clostridium perfringens toxinotypes.
| Strain # | Enzyme immunoassay | Immunochromatography | Clostridium perfringens toxinotype | ||
|---|---|---|---|---|---|
| Result | Measured toxin concentration | Result | Measured toxin concentration | ||
| 89–87 | NEGATIVE | < LoD | NEGATIVE | < LoD | A (alpha) |
| 73–20144 | NEGATIVE | < LoD | NEGATIVE | < LoD | C (alpha, beta) |
| CWC238 | NEGATIVE | < LoD | NEGATIVE | < LoD | C (alpha, beta) |
| NCTC3181 | NEGATIVE | < LoD | NEGATIVE | < LoD | B (alpha, beta, epsilon, delta) …with lost epsilon toxin-encoding plasmid |
| CP-AO | POSITIVE | 119 μg/mL | POSITIVE | ≈ 100 μg/mL | D (alpha, epsilon) |
| 180–08 | NEGATIVE | < LoD | NEGATIVE | < LoD | A (alpha) |
| 71–2097 | POSITIVE | 459 ng/mL | POSITIVE | ≈ 300 ng/mL | B ((alpha, beta, epsilon) |
| CP-A4 | POSITIVE | 3.4 μg/mL | POSITIVE | ≈ 3 μg/mL | D (alpha, epsilon) |
| 93R | NEGATIVE | < LoD | NEGATIVE | < LoD | A (alpha, beta2) |
| CWC245 | NEGATIVE | < LoD | NEGATIVE | < LoD | C (alpha, beta) |
| CP48 | POSITIVE | 1.7 μg/mL | POSITIVE | ≈ 3 μg/mL | D (alpha, epsilon) |
| CP47 | NEGATIVE | < LoD | NEGATIVE | < LoD | A (alpha) |
| 73–20115 | POSITIVE | 235 ng/mL | POSITIVE | ≈ 300 ng/mL | B (alpha, beta, epsilon) |
| NCIB10748 | NEGATIVE | < LoD | NEGATIVE | < LoD | E (alpha, iota) |
| 667–76 | NEGATIVE | < LoD | NEGATIVE | < LoD | alpha negative |
| 230–09 | POSITIVE | 2.4 μg/mL | POSITIVE | ≈ 3 μg/mL | D (alpha, epsilon) |
| 226–12 | POSITIVE | 4.6 μg/mL | POSITIVE | ≈ 3 μg/mL | B (alpha, beta, epsilon) |
| 420–13 | NEGATIVE | < LoD | NEGATIVE | < LoD | A (alpha) |
18 culture supernatants from different Clostridium perfringens strains from the French National Reference Center for Anaerobic Bacteria and Botulism (M. Popoff) were tested and titrated, in a blind study, using the O/N sequential enzyme immunoassay and the immunochromatographic test. The decoding is shown in the right column.
LoD, limit of detection.