Chronic WOUNDS

Bacteria usually exist in one of two states: planktonic, existing as free moving cell in the environment, or sessile, attached to a surface. Bacteria in the environment tend to form aggregates or colonies attached to the surface of non-living or living substrates. These aggregated cells secrete a glue-like substance primarily made of exopolysaccharide and proteins, called extracellular polymeric substance (EPS). The EPS completely encases them, offering protection from the external environment and forms a biofilm. The sessile bacterial cells within the matrix of the biofilm are characterised by their lack of movement (Costerton, 1999), whereas the planktonic cells are dispersed from the biofilm and colonise other areas.