FIG. 3.

(A through F) Time sequence of the active release by Tetrahymena SSU of a vesicle (black arrows) containing S. enterica serovar Thompson cells after the starved cells of the protozoan grazed on this human pathogen. Note the membrane protruding from the Tetrahymena cell at the time of vesicle release (panels E and F, white arrows). The differential interference contrast images were acquired through a Nikon Microphot microscope with a VHS video, and the frames were converted to digital images. Bar, 10 μm.