The reaction of ovine neutrophils to Histophilus ovis in relation to genital infection of rams.

Histophilus ovis was shown to be phagocytized by neutrophils when the organisms enter the lumen of the reproductive tract of the ram. The phagocytosis and destruction of H. ovis by neutrophils was demonstrated in vitro by the viable count method and by electron microscopy. It was shown that immunoglobulins and complement had no influence on the phagocytosis and destruction of H. ovis. Phagocytosis and killing of H. ovis was accomplished equally well by neutrophils from immunized and non-immunized rams. Immunized rams showed a massive infiltration of neutrophils into the walls, epithelium and lumen of their ampullae when dead H. ovis were introduced into their lumen.