Biofilm Formation of Staphylococcus aureus

Biofilm is considered as part of the normal life cycle of Staphylococcus aureus in the environment, in which planktonic cells present attach to solid surfaces, proliferating and accumulating in multilayer cell clusters embedded in an organic polymer matrix. The structural components of this extracellular matrix, mainly proteins and polysaccharides, allow the accumulation of biomass, as well as the cohesion and stabilization of the biofilm. In addition, the presence of extracellular DNA into the biofilm matrix can promote the horizontal gene transfer and, thus, the spreading of antimicrobial resistances between embedded cells. Biofilm protects the bacterial community from environmental stresses, from the host immune system, and from antimicrobial attacks, as opposed to the situation for exposed planktonic cells. Moreover, the dispersal of biofilm cells in clumps may provide a sufficient number of cells for an infective dose that is not typically found in bulk fluid, enabling an enhanced transmission and infection of S. aureus.