Influences of exogenous addition of DSF signal on the bacterial growth rate (A) biofilm formation (B), and persistence (C) of B. cereus . For measurement of growth rate, the bacterial cells were grown in the absence or presence of 50 μM DSF; while for test of persistence, the bacterial cells were treated with10 μg/ml gentamicin (Gm) in the absence or presence of 50 μM DSF signal. For biofilm formation assays, DSF signal was added at different final concentrations as indicated. Data shown are means of three replicates and error bars indicate the standard deviations. The differences between the samples with DSF and without DSF are statistically significant with *p < 0.05, as determined by using the Student t test.