Antibody increases phagocytosis and killing of Lactococcus garvieae by rainbow trout (Oncorhynchus mykiss, L.) macrophages.

The present study reports that specific antibody increased the bactericidal activity of rainbow trout head-kidney macrophages against virulent capsulated Lactococcus garvieae in the absence of complement. The observed increased bactericidal activity appeared to result from increased phagocytosis of capsulated L. garvieae in the presence of specific antibody and may in part explain the protective effect of antibody previously reported against this disease.