FIG 5.
Curli intermediates are more cytotoxic than mature aggregates. (A) An LDH assay was used to determine the percentage of cytotoxicity in BMDMs treated with curli preparations from high-turbulence and low-turbulence cultures. Shown are means and a representative experiment from three independent experiments. (B) Images of BMDMs seeded at 2.5 × 105 cells/well and not treated (NT) or treated with curli preparations from high-turbulence or low-turbulence cultures or with S. Typhimurium (STM). Cells were stained with NucBlue, which stains nuclei of live cells, and NucGreen, which stains nuclei of dead cells. Each image is a small portion of the full well. Representative images are shown for one of three independent experiments. (C) The ratios of dead to live cells obtained by analysis of multiple images accounting for the central 20% of well per condition in duplicate. Plotted are means (±SEM) from all images per condition. The asterisks indicate significant difference between the effects of preparations from high- and low-turbulence cultures. (D) The ratios of dead to live cells obtained by analysis of multiple images accounting for the central 20% of the well per condition in duplicate. Plotted are means (±SEM) from all images per condition. **, P < 0.01; ***, P < 0.001.