Fig. 4.

Quantification of bacterial replication using high-content imaging. (A) THP1 cells infected with B. cenocepacia at MOI 1 for 24 h. Nuclei (blue) of viable cells were identified using parameters described in the Materials and Methods section. Bacteria (green) were enumerated within 10 μm of the center of viable nuclei to restrict counting to intracellular bacteria. (B) Infection rate of THP1 cells infected with B. cenocepacia at MOI 1 for 24 h. (C) Average bacterial replication rate (per infected cell) in THP1 cells infected with B. cenocepacia at MOI 1 for 24 h. Scale bars = 50 μm. NS, nonstimulated; FK, formalin-killed bacteria; WT, wild-type bacteria. Data shown are representative images (A) or combined measurements (B and C; mean + SEM) from four independent experiments. ****P < 0.0001 (two-tailed t-test).