TABLE 2.
Killing of N. meningitidis group B strains by whole blood from subjects with serum bactericidal titers of <1:4
| Test strain | No. of SBA-negative subjects | No. (%; 95% CI) of blood samples with killing activity according to definition:
|
Killing inhibited by group B polysaccharidec (no. of samples with inhibited activity/no. of samples with killing activity) | |
|---|---|---|---|---|
| 1a | 2b | |||
| 8047 | 12 | 10 (83; 55-95) | 5 (42; 19-68) | 1/10 |
| NZ98/254 | 13 | 5 (38; 18-64) | 3 (23; 8-50) | 2/5 |
| BZ232 | 14 | 5 (36; 16-61) | 4 (29; 12-55) | 1/5 |
a
Defined as a ≥1 log10 decrease in CFU/milliliter after 2 h of incubation compared to the CFU/milliliter at time zero.
b
Defined as a ≥2 log10 decrease in CFU/ml after 1 h of incubation compared to the CFU/milliliter at time zero.
c
Data are for blood samples showing killing as specified by definition 1 and showing a greater than 90% inhibition of killing when the blood contained 50 μg/ml of group B polysaccharide.