Figure 1.

Schematic of the biofilm cultivation apparatus. Biofilms were grown for 75 days and treated with antibiotics from day 15 to day 30. Triplicate biofilms were destructively sampled at the time points denoted with blue triangles (18, 21, 25, and 30 days for kanamycin and 20, 25, and 30 days for rifampicin). Day 30 biofilm samples were used to inoculate a planktonic population that was serially passaged in the absence of antibiotics for 250 generations