TABLE 2.
Complement-dependent bactericidal activity against E. coli O157:H7 elicited in serum of mice injected with O157 O-SP conjugated to Stx1B
| Substance or immunogen injected and serum sample | Activity of anti-LPS (EU)a
|
Bactericidal titerb | |
|---|---|---|---|
| IgG | IgM | ||
| Saline | <1 | <1 | <10 |
| OSP-AH-StxB1 | |||
| 1 | 285 | 14 | 50 |
| 2 | 155 | 15 | 50 |
| OSP-StxB1 | |||
| 3 | 265 | 12 | 200 |
| 4 | 241 | 28 | 200 |
a
IgG or IgM anti-LPS levels of serum samples from four individual mice were assayed for bactericidal titer.
b
The reciprocal bactericidal titer is the highest serum dilution yielding 50% killing of E. coli O157:H7. Absorption with LPS removed the bactericidal activity from sera (titer, <10).