Inhibition of Yeast Phagocytosis in Macrophage Cultures Treated With Slime Polysaccharide Purified From Pseudomonas aeruginosa

This study was initiated to determine whether purified slime polysaccharide(PSP) from P aeruginosa inhibits the ingestion of heat killed Saccharomyces cerevisiae particles in macrophage cultures. Relative to controls, direct phagocytosis assays revealed that the percentages of phagocytes and the numbers of ingested yeast particles per phagocyte decreased in a dose-dependent manner in PSP-treated cultures. Thus, PSP may act as a virulence factor in vivo by impairing the phagocytic capacity of macrophages.