PHAGOCYTOSIS, KILLING, AND OXIDANT PRODUCTION BY BOVINE MONOCYTE-DERIVED MACROPHAGES UPON EXPOSURE TO BRUCELLA-ABORTUS STRAIN 2308

Phagocytosis and intracellular survival of Brucella abortus, and oxida nt production by monocyte-derived macrophages from ten B. abortus-naiv e cows were studied. Phagocytosis of bacteria opsonized with naive-aut ologous sera or reactor serum was significantly less than phagocytosis of bacteria opsonized with fetal bovine serum. After phagocytosis, in tracellular survival of bacteria opsonized with naive-autologous or re actor sera was significantly less than survival of bacteria opsonized with fetal bovine serum. Production of oxidant by macrophages stimulat ed with B. abortus opsonized with naive-autologous, reactor, or fetal bovine sera was not significantly different. Although macrophages from one animal showed significantly less phagocytic activity, intracellul ar killing and oxidant production by macrophages from the ten individu al cows toward B. abortus opsonized with naive-autologous, reactor, an d fetal calf sera were homogeneous. The abilities of the macrophages t o phagocytize and to kill B. abortus were not associated with each oth er or with oxidant production. Innate resistance or sensitivity to B. abortus was not identified in the cows based on macrophage function.