AVIAN HETEROPHILS AND MONOCYTES - PHAGOCYTIC AND BACTERICIDAL ACTIVITIES AGAINST SALMONELLA-ENTERITIDIS

The ability of heterophils and monocytes from domestic chickens and tu rkeys to phagocytize and kill Salmonella enteritidis (SE) was investig ated using both a standard plate count (chickens only) and direct micr oscopic examination by staining with acridine orange (both chickens an d turkeys). Optimal phagocytosis of SE by both chicken and turkey phag ocytes required opsonization of the bacteria by antibodies as determin ed by both assays. However, heterophils from both the turkeys and chic kens phagocytized more SE than did monocytes from either type of fowl. Regardless of the presence or absence of antibodies, heterophils were more efficient bactericidal cells than were the monocytes since only heterophils killed the intracellular bacteria while the majority of no nopsonized SE survived in the monocytes. Phagocytosis of SE did not re sult in an increase in the amount of superoxide anion released by the heterophils suggesting that the ultimate fate of the bacteria in these cells was not related to an oxygen-dependent mechanism.