TABLE 5.
Serum Abs (micrograms per milliliter) to CDTA elicited in mice by recombinant enterotoxin A (rARU) or polysaccharides bound to rARU alone or succinylated (rARUsucc)a
| Conjugate | rARU injected (μg) | Geometric mean (25th to 75th percentile) by ELISA for injection:
|
||
|---|---|---|---|---|
| First | Second | Third | ||
| rARUb | 6.94 | ND | ND | 717 (621–863) |
| Pn14-rARU | 1.29 | 3.70 (2.55–5.08) | 80.1 (69.8–131) | 194 (113–236) |
| Pn14-rARUsucc | 7.30 | 7.94 (5.21–11.3) | 183 (146–175) | 371 (274–463) |
| SF-rARU | 3.90 | ND | 433 (258–609) | 613 (485–778) |
| SF-rARUsucc | 6.94 | ND | 191 (118–291) | 518 (366–615) |
| SF-rARUb | 3.90 | ND | ND | 437 (372–547) |
| SF-rARUsuccb | 6.94 | ND | ND | 242 (172–443) |
| K1-rARUsucc | 8.08 | 10.7 (6.75–17.2) | 84.9 (72.5–131) | 390 (279–470) |
Six-week-old mice were injected s.c. with 2.5 μg of polysaccharide as a conjugate at 2-week intervals. Groups of mice (n = 10) were exsanguinated before the first injection and 7 days after the second and third injections, and their sera were assayed for anti-CDTA by ELISA. A hyperimmune serum, arbitrarily assigned a value of 100 EU, served as a reference. ND, not done. Statistical significance: 183 versus 7.94, P = 0.0001; 371 versus 183, P = 0.0005; 80.1 versus 3.70, P = 0.0001; 194 versus 80.1, P = 0.007; 7.94 versus 3.70, P = 0.01; 183 versus 80.1, P = 0.004; 371 versus 194, P = 0.01.
hsd/ICR mice. The remainder were NIH Swiss Albino mice.