FIG 6.

Spore and yeast pathways to secondary fungemia. Inoculated spores are readily phagocytosed by macrophages and neutrophils, but survival is more likely within macrophages. Spores germinate and survive within macrophages, endothelial cells, or a combination of these. Secondary fungemia represents a cycle of release from the intracellular compartment and brief extracellular periods in the bloodstream. Possible fates of circulating cryptococci include brain invasion (A), replication within the circulation (B), clearance (especially by neutrophils) (C), or reuptake by macrophages and eventual repetition of the cycle. Inoculated yeast cells undergo a similar process, but their residency within the endothelium is either much more limited or more rapidly interrupted by macrophages.