Figure 4.
The impact of dHL60 cells on the formation of biofilms by Bcc bacteria. Bacteria (1 × 105 cfu) were cultured in 96-well plates in the absence or presence of (A–C) dHL60 cells (1 × 106 cells), (D–F) an equivalent quantity of whole-cell lysate thereof, or (G–I) DNA derived from an equivalent number of cells, for up to 72 h. In some cases, additional dHL60 cells or cellular material were added 24 h after initial inoculation. Biofilm density was assessed after 24, 48 or 72 h by crystal violet staining. Asterisks indicate significant differences between normal biofilm biomass and biofilm formed in the presence of dHL60 material (*P < 0.05, **P < 0.01, ***P < 0.001, two independent sample t-test). Bullets indicate significant differences comparison between normal biofilm biomass and biomass after two additions of dHL60 material (•P < 0.05, ••P < 0.01, •••P < 0.001). Crosses indicate significant differences between biofilm formed in the presence of dHL60 material vs biomass after two additions of dHL60 material (†P < 0.05, ††P < 0.001). Data are expressed as the mean (± SD) of four biological replicates from each of three independent experiments.