FIG. 2.

B. abortus replication assessed by confocal microscopy. After fixation, permeabilization, and immunolabelling of bacteria, HeLa cells were observed by analyzing reflection and fluorescence of cells and bacteria, respectively. Superimposed images of reflection and fluorescence are presented. (A, B, and C) Cells were infected with strain 2308 and observed at 4, 24, and 72 h p.i., respectively. (D, E, and F) Cells were infected with strain 19 and observed at the above-mentioned times, respectively. Bar, 10 μm.