Attachment to uncoated material is mainly dependent on cell surface hydrophobicity, while dedicated surface proteins mediate adhesion to host matrix-covered devices. Afterwards, exopolysaccharide, specific proteins, and accessory macromolecules provide intercellular aggregation. Mechanisms of biofilm maturation, structuring, and detachment are poorly understood, but possibly involve quorum-sensing controlled expression of detergent-like peptides and proteolytic activity in exposed layers of the biofilm. Genome-wide gene expression is significantly different in the biofilm compared to the planktonic mode of growth and includes down-regulation of basic cell processes.