Effect of dihydrostreptomycin on phagocytosis of mouse-peritoneal macrophages in vitro.

The effect of the antibiotic dihydrostreptomycin on the phagocytic and bactericidal ability of peritoneal macrophages obtained from mice has been investigated. In subliminal concentrations which did not influence the bacterial growth, the drug caused macrophages to ingest and kill bacteria (Escherichia coli) at a higher rate than did macrophages without antibiotic. The differences for phagocytosis and intracellular killing of E. coli with and without a subliminal amount of dihydrostreptomycin were statistically significant. Macrophages pretreated with the antibiotic did not demonstrate any enhancement of phagocytosis.