Fig. 5. Combination treatment of 3H3 and antibiotic leads to biofilm eradication.

a Biofilms (dashed white arrow) were established in the presence (untreated) or absence of 0.5 mg/ml 3H3 on medical grade catheters in vitro. After 72 h biofilms were stained with Syto9 (green) and amyloid curli stain Congo Red (red) and imaged using Leica TCS confocal microscopy at ×63. Scale bars represent 25 μm. Inserts are ×3 zoom images. Catheters exhibit green autofluorescence (solid white arrow). b Biofilms were established on medical grade catheters in vitro 24 h prior to insertion of catheters into flanks of mice. At 24 and 48 h post insertion, 100 μg 3H3 was injected in vivo percutaneously into the catheter lumen. Where applicable, drinking water was supplemented with 1 mg/ml ampicillin beginning 24 h prior to catheter insertion. At 72 h after catheter insertion mice were euthanized and catheters were removed, stained with Syto9 (green) and Congo Red (red), and imaged using a Leica TCS confocal microscopy at ×63. Scale bars represent 25 μm. Insets are ×3 images. Catheters exhibit green autofluorescence.