Phagocytosis and intracellular killing of Pseudomonas aeruginosa by peritoneal macrophages of mice.

The poorly mucoid P. aeruginosa 87 strain was better phagocytized by peritoneal macrophages from normal mice than highly mucoid P. aeruginosa 219. However, the macrophages killed significantly greater number of mucoid bacterial cells of P. 219 strain. The immunization of mice with 10, 50 or 100 micrograms of slime-extract P. 87 or P. 219 did not significantly enhance the phagocytic and bactericidal properties of macrophages. The vaccination of animals with viable bacterial cells of P. 219 strain, using several schemes of treatment, slightly augmented both activities of macrophages but the differences between them and control group were statistically not significant. However, the ingestion and killing of the bacteria were suppressed when macrophages were harvested from mice treated with 200 or 400 micrograms of slime-extract P. 219.