Adhesion of bacteria to surfaces and biofilm formation on medical devices

Biofilm formation allows otherwise unicellular organisms to assume a temporary communal lifestyle. This multicellular lifestyle affords protection from harsh environmental insults and provision of centralized and concentrated resources, such as nutrients and genetic exchange opportunities. This chapter describes the stages leading to bacterial biofilm formation with emphasis on the crucial initial steps of finding, interacting with, and adhering to a surface. These interactions are followed by irreversible attachment, microcolony development, and biofilm maturation. Although the general stages leading to biofilm formation are similar across pathogens, the adhesive fibers, proteins, nucleic acid, and exopolysaccharide material associated with a biofilm can be distinct in a species- or even strain-specific manner. Likewise, the architecture, kinetics, microbe-microbe interactions (in polymicrobial biofilms), and regulatory components controlling biofilm formation vary from pathogen to pathogen. Examples of different adhesive mechanisms utilized by several key bacterial pathogens that cause detrimental biofilms on medical devices are described.