Biofilm-associated infections affect millions of people and are a leading cause of death and disability. With progress of medical sciences, more and more indwelling devices for the purpose of medical treatments and foreign body implants are applied. Infection continues to be a major complication of their use. Many efforts to decrease the burden of biofilm-assciated infections have been made, however there is still no anti-biofilm compund in clinical use. In this project, we concentrate on enhancing the activity of common antibiotics. Many of today´s antibiotics are very effective in the treatment of bacterial infections. However, their use in the successful eradication of biofilm-associated infection relies on our ability to overcome biofilm tolerance. The objectives of this project were defined in order to obtain new knowledge on the mechanisms of biofilm tolerance of the gram-negative pathogen Pseudomonas aeruginosa in order to improve current diagnostics and to develop effective therapeutic intervention strategies for the control of biofilm-associated infections.