The effect of lysozyme on the complement-dependent bactericidal action of different antibody classes

Preparations of rabbit, dog and sheep IgA, IgA and IgM were examined for their antibacterial effects using a complement-dependent bactericidal assay. IgM and IgG were efficient bactericidal antibodies in the presence of complement; IgA, however, contained negligible activity. Except for sheep IgG no enhancement of bactericidal activity was observed in the presence of added lysozyme.