FIG 2 .

Increasing cellular cholesterol leads to C. burnetii death. (A) Representative live-cell microscopy images of cholesterol-free MEFs and MEFs with cholesterol and infected with mCherry-expressing C. burnetii (mCherry-C. burnetii). Note the presence of mCherry fluorescence in the PV lumen in MEFs with cholesterol. The white arrows point to the PVs. Bars = 10 µm. (B) Quantitation of lytic PVs containing degraded bacteria under different cholesterol conditions. At different times postinfection, PVs were observed by live-cell microscopy and scored as lytic if visible mCherry fluorescence was present in the lumen. The means ± SEM from three experiments are shown. The means were compared by one-way ANOVA with Tukey’s posthoc test. *, P < 0.05 compared to the value with no cholesterol. (C) Cholesterol leads to fewer viable bacteria. C. burnetii-infected cholesterol-free MEFs were grown with different cholesterol concentrations, and the number of viable bacteria was determined by fluorescent infectious focus-forming unit (FFU) assay. Error bars show the SEM of the averages of three individual experiments done in duplicate. Means were compared by one-way ANOVA with Tukey’s posthoc test. *, P < 0.05 compared to the value with no cholesterol.