Fig. 3.

Association and localization of bacteria during interaction with amoeba. (A) Fluorescence-activated cell sorting analysis showing fluorescence of cell populations from pure culture of strain DEF010 (GFP positive) (bacteria; top), cocultivation of bacteria and amoebae (middle), or pure culture of amoebae (bottom) over a 14-day period. The vertical axis represents cell number, and the horizontal axis represents log fluorescence intensity. The percentage of fluorescent cells is indicated on the right of the histogram, and the mean intensity of fluorescence is indicated in the top right corner in italics. One representative experiment is shown. (B) Epifluorescence microscopy of samples taken from coculture flasks at various time points. Arrows show bacteria; V, vacuole; C, cyst; T, trophozoite. Original magnification, ×1,000. Scale bar, 10 um.