In vitro determination of phagocytosis and intracellular killing of Brucella melitensis by goat's polymorphonuclear phagocytes.

One hundred and forty samples of goats serum taken from animals suspected of having brucellosis, have been studied by trying to assess the phagocytosis in vitro of Brucella melitensis Rev-1 by polymorphonuclear neutrophil phagocytes opsonized with antibrucella serum. The serum agglutination test and the Coombs antiglobulin test were carried out with the serum samples. The opsonization ingestion, intracellular killing and germ killing power of the serum were also assessed. The results demonstrate that the phagocytic activity of the polymorphonuclear neutrophils opsonized by a particular serum can be of use to determine its titre; its opsonic activity varies according to whether the serums are inactivated or not. Likewise it shows the resistance of Brucella meilitensis Rev-1 to digestion by caprine polymorphonuclear neutrophils, this resistance being independent of the animal's degree of infection.