Figure 1. Model of biofilm development and modes of escape.

Based on the analysis of single species biofilms, the formation of biofilms occurs in a stage-specific and progressive manner. The developmental process is initiated by single planktonic cells making contact with the surface. With respect to biofilm formation, several developmental steps are discernable as reversible attachment, irreversible attachment, and biofilm maturation [2,8]. Cells can escape from the biofilm via desorption, detachment, and dispersion. Detachment mechanisms include erosion and sloughing. Erosion describes the continuous removal of biomass while sloughing entails the removal of intact pieces of biofilm or the entire biofilm. In biofilm dispersion, the inside of a biofilm microcolony becomes fluid, and cells within this zone begin to show signs of agitation and movement. Cells escape the biofilm microcolony via a disruption in the microcolony wall through which cells evacuate, entering the bulk liquid as single bacteria.