FIG. 4.

Intracellular survival of differently opsonized brucellae following uptake by nonadherent and adherent human monocytes. Freshly isolated PBM were challenged with B. suis for 20 min and chased for 1 to 36 h. Viable bacteria reisolated from osmotically lysed PBM were determined by count of CFU. (Top panel) Survival of nonopsonized brucellae internalized by nonadherent (non-adh.) and adherent PBM. (Bottom panel) Survival of brucellae internalized by nonadherent PBM in the presence of either hiFCS, fresh FCS, or 5 μl of human anti-Brucella immune serum per ml in hiFCS (hiFCS/HIS). Results are expressed as means ± standard deviations for duplicate samples from one of three experiments with monocytes from different donors which gave comparable results.