Fig. 1: Incubation of S. Typhimurium biofilms with anti-amyloid mAbs reduces biofilm thickness and curli content.

a S. Typhimurium was cultured in the absence of mAb (untreated) or in the presence of 0.5 mg/ml control antibody 6A or 0.5 mg/ml 4A6, 4G1, 2C10, or 3H3. Isogenic mutant S. Typhimurium csgBA was included as a negative control. After 72 h, biofilms were stained with the bacterial stain Syto9 (green) and amyloid stain Congo Red (red), washed extensively, and imaged using a Leica TCS confocal microscopy at ×63. ImageJ was used to create 3D reconstructions of z-stacks using the 3D projection application. Scale bars represent 25 μm. b Biofilm thickness (μm) was determined from z-stacks using Leica TCS software. c Mean relative fluorescent units (RFU) of the red channel calculated from z-stacks using ImageJ. d Biofilms were grown in the absence (untreated) of antibody or in the presence of 0.5 mg/ml 6A, 4A6, 4G1, 2C10, or 3H3. csgBA was included as a negative control. After 72 h, biofilms were stained with crystal violet, and the optical density at 570 nm was determined. Representative images of crystal violet staining are shown below the graph. Mean and SE were calculated from results from at least two independent experiments. *p < 0.05, **p < 0.01 as determined by Student’s t-test.