Identification of adaptive mechanisms leading to reduced antibiotic susceptibility in bacterial biofilms using experimental evolution. Part 3: Pseudomonas aeruginosa floating biofilms in synthetic cystic fibrosis medium. Identification of adaptive mechanisms leading to reduced antibiotic susceptibility in bacterial biofilms using experimental evolution. Part 3: Pseudomonas aeruginosa floating biofilms in synthetic cystic fibrosis medium

Pseudomonas aeruginosa was repeatedly and intermittently exposed to tobramycin. Bacteria were grown in synthetic cystic fibrosis medium in wells of a 96-well microtiter plate. After 24 hours, more medium with or without tobramycin was added. After another 24 hours of incubation, a subsample of the well content was used to inoculate fresh synthetic cystic fibrosis medium in a 96-well microtiter plate. This was repeated for a total of 15 cycles. Evolved lineages were then DNA-sequenced to screen for genome changes.