TABLE 2

Effect of human complement concentration and preadsorption on nonspecific killing and OI

ComplementComplement concn (%)Strain (serotype)Result for human serum sample 58
NSKa (%)OIbMaximum killing (%)
Pooled human, nonadsorbed4OC24452 (O1A)91c
4OC24453 (O2)90
4OC24454 (O6A)85
4OC24176 (O25B)90
7OC24452 (O1A)98
7OC24453 (O2)96
7OC24454 (O6A)95
7OC24176 (O25B)99
Pooled human, preadsorbed, lowd4OC24452 (O1A)918999
4OC24453 (O2)1020594
4OC24454 (O6A)2860296
4OC24176 (O25B)18460100
7OC24452 (O1A)3549100
7OC24453 (O2)846299
7OC24454 (O6A)763,05395
7OC24176 (O25B)35605100
Pooled human, preadsorbed, highe7OC24452 (O1A)1219399
7OC24453 (O2)1628599
7OC24454 (O6A)42764100
7OC24176 (O25B)14647100
  • a NSK, nonspecific killing.

  • b OI, opsonization index.

  • c —, not determined because NSK was ≥85%.

  • d Complement preadsorbed with glutaraldehyde-treated E. coli at a ratio of 2 × 109 CFU of each strain (OC24452, OC24453, OC24454, OC24176) per 1 ml complement.

  • e Complement preadsorbed with glutaraldehyde-treated E. coli at a ratio of 2 × 109 CFU of strain OC24452 or OC24453, 7 × 109 CFU of strain OC24454, and 4 × 109 CFU of strain OC24176 per 1 ml complement.