TABLE 3.
Cytotoxic activity of purified toxins from prevalent C. difficile toxinotypes and relative efficacy of neutralization by sera from vaccine-immunized hamsters
| Toxinotype | PCR ribotype | Value for purified native toxina: |
|||
|---|---|---|---|---|---|
| A |
B |
||||
| CD50 (ng/ml) | RE | CD50 (ng/ml) | RE | ||
| 0 | 087 | 4.4 | 52.3 | 0.2 | 38.1 |
| 001 | 15.9 | 24.4 | 108.0 | 818.5 | |
| 002 | 5.8 | 44.4 | 98.1 | 387.4 | |
| 014 | 8.9 | 68.3 | 6,220.0 | 95.7 | |
| III | 027 | 5.4 | 17.8 | 3.5 | 9.3 |
| IV | 023 | 9.4 | 15.4 | ND | ND |
| V | 078 | 6.9 | 14.1 | 4.5 | 13.1 |
| VIII | 017 | ND | ND | 17.1 | 149.7 |
a
CD50, concentration of toxin inducing 50% cytotoxicity; RE, relative efficacy of neutralization, considered statistically significant if above the threshold value of 5.4; ND, not determined. Data represent geometric means of results from 3 independent experiments.