Figure 4

dC4 and dN4 inhibit formation of and eliminate established A. baumannii biofilm. (A) dC4 and dN4 inhibition of A. baumannii biofilm formation. A. baumannii biofilm was grown in LB medium containing serial concentrations of dC4 or dN4 and stained with 0.1% crystal violet. Staining was detected by measuring the absorbance at 550 nm. Data are expressed as the means ± standard deviations of triplicate experiments; ***P < 0.001 by 1-way analysis of variance. (B) dC4 and dN4 elimination of A. baumannii biofilm. LB medium containing serial concentrations of dC4 or dN4 was added onto formed A. baumannii biofilm. After overnight incubation, the survived bacteria were quantified by plating on LB agar plates. Data are expressed as means ± standard deviations of triplicate experiments; ***P < 0.001 by 1-way analysis of variance. (C) Confocal laser scanning microscopy images show dC4 and dN4 elimination of A. baumannii biofilm. LB medium with or without 256 μg/mL of dC4 or dN4 was added to established A. baumannii biofilm. A. baumannii were labeled with GFP (green). After overnight incubation, the biofilms were observed by confocal microscope (400 × magnification).