EN
Interaction between T. vaginalis and P. aeruginosa was studied in vitro. Protozoan cells were incubated in 0,9% NaCl at 37°C for 30 and 150 min. with bacteria, alive or killed by heating for 10 min. at 100°C. Transmission electron microscope observations showed weak fagocytic activity (<10%) of T. vaginalis against living P. aeruginosa. Phagocytosis of these bacteria caused death of T. vaginalis. Desintegration and autolysis of T. vaginalis resulted probably from action of exotoxin A produced by P. aeruginosa. Phagocytosis of dead P. aeruginosa has not been observed.