The major research interest of the past 10 years has been microbial biofilms in relation to cell-cell interactions and developmental processes. The knowledge obtained in the course of this work is now being further developed in connection with detailed studies of microbial adaptation and evolution in cases of chronic infections. These current research activities are based on the assumption that fundamental studies of bacteria physiology and ecology are essential if we wish to understand and eventually interfere with such microbial infections. The investigations employ several methods providing global information about the cells’ genomes and functional genomics. In particular, specific clones of bacteria infecting airways of cystic fibrosis patients are studied. In connection with these studies evolution of antibiotic resistance is an important topic where the current focus point is resistance mechanisms involved in tolerance to anti-microbial peptides. Development of various types of laboratory model systems for simulation of human infections in vitro has been added to the research program.