Reduced microbicidal activity of peripheral mononuclear phagocytic cells infected with Pasteurella multocida.

Pasteurella multocida inhibits the uptake and killing of Candida albicans and P. multocida by avian mononuclear phagocytic cells. The toxic outer membrane protein of P. multocida, which has been previously described, also inhibited the uptake and killing of C. albicans. Antibody specific for the toxic outer membrane protein reversed this effect resulting not only in an increase in uptake of C. albicans and P. multocida, but also in intracellular killing of P. multocida. This antibody, however, only partially restored killing of C. albicans. These data support the hypothesis that P. multocida is capable of intracellular survival in avian mononuclear phagocytic cells and that the toxic outer membrane protein is totally or partly responsible for this occurrence.