In vitro killing of Pasteurella multocida: the effect of rabbit granulocyte and specific antibody source

In vitro granulocyte-killing assays were performed to examine the ability of granulocytes from pasteurella-free or immunized rabbits, the in combination with specific immune serum, to kill Pasteurella multocida. Granulocytes from healthy rabbits and from rabbits with P multocida infections were equally competent. Granulocyte source, serum source, and specific antibody titer had no effect on granulocyte phagocytic activity. Moreover, serum containing specific antibody and complement supported the growth of the bacterium. These data suggest that chronic P multocida infections are not attributable to defective granulocytes or lack of serum antibody production.