Phagocytosis of Staphylococcus aureus by cultured bovine aortic endothelial cells: model for postadherence events in endovascular infections.
We examined the interaction of Staphylococcus aureus with cultured bovine aortic endothelial cells as a model for the initial events in the pathogenesis of endovascular infections. Confluent monolayers of cultured endothelial cells were incubated with S. aureus. Cell-associated bacteria were measured by washing away nonadherent organisms, disrupting the monolayers, and performing quantitative cultures. Phagocytosis was differentiated from adherence by treating the cells with lysostaphin; approximately 60% of cell-associated bacteria was found to be intracellular. Phagocytosis could be blocked by using cytochalasin B, which interferes with microfilament function. Addition of fibronectin resulted in a 63% increase in adherence of S. aureus to the endothelial cells but did not increase ingestion. Transmission electron microscopy demonstrated a sequence of events similar to that which occurs during ingestion by professional phagocytes, including: adherence of bacteria to the endothelial cell; formation and elongation of surface extensions of the endothelial cell to surround the adherent bacteria; and complete enclosure within apparent phagosomes. Phagocytosis of bacteria by endothelial cells, followed by intracellular persistence, may be an important postadherence event in the pathogenesis and pathophysiology of endovascular infections.
D000818:Animals; D001422:Bacterial Adhesion; D002417:Cattle; D002478:Cells, Cultured; D004727:Endothelium / Q000502:physiology* / Q000648:ultrastructure; D005353:Fibronectins / Q000502:physiology; D008954:Models, Biological; D010587:Phagocytosis; D013211:Staphylococcus aureus / Q000276:immunology*
D005353:Fibronectins