Bactericidal activity of human sera with a physiologic or genetic defect of the complement system.

The serum of patient suffering genetically conditioned C2 defect showed a weak bactericidal activity against Pseudomonas aeruginosa strains. Out of 23 tested strains one was susceptible comparing with 16 ones sensitive to normal human serum. The normal cord serum exerted a bactericidal effect on 8 strains. All sera were found to be active against Salmonella strains tested.