FIG 3.

Cell vulnerability can be predicted from the number of bacteria previously internalized. (A) Distribution of the number of intracellular bacteria detected at 1.5 h p.i. in HeLa cells (average from three replicates). The infection efficiencies are clustered in three groups: low, medium, and high infection, corresponding, respectively, to 1 to 2, 3 to 8, or more than 9 bacteria per cell. (B) The vulnerability score is represented as a function of the number of intracellular bacteria resulting from the first infection in HeLa cells. (C) Probability of a cell to be highly infected during the second infection (I₂ ≥ 9) as a function of the number of intracellular bacteria being internalized during the first infection in HeLa cells. Values in panels B and C represent the data merged from all the experiments (delay of 1, 2, and 3 h before the second infection). Infection efficiency groups are identical for experiments shown in all panels.