Figure 6.

Treatment of antibiotic-resistant variants in PA-Xen41 lawn biofilm in the incubator (37 °C and 5% CO₂). (a) The placement of TOB loaded sources i.e. paper disks, and electrodes is shown at t = 0 h. The electroceutical treatment was started at t = 72 h i.e., current was turned ‘on’ after the resistant variants emerged (red dots in the zones of inhibition around the TOB sources) and continued for the next 24 h. The resistant phenotypes present in the zones with estimated radii ranging between ~10.7 mm and ~21.4 mm from the center of each paper disk (dotted circles) were eliminated on the anode after 24 h of electroceutical treatment (at t = 96 h) while no such effect was observed over the cathode as determined by IVIS imaging. The last panel for IVIS imaging (bottom right) shows a zoomed in activity map at t = 96 h on anode (+) and cathode (−). (b) Tobramycin (TOB) concentrations were modeled as a function of time at radii ~10.7 mm and ~21.4 mm from a TOB-loaded (100 µg) disk. At t = 96 h, TOB concentrations were 13.34 μg/mL and 7.02 μg/mL at inner and the outer radii respectively.