EXTRACELLULAR POLYMERIC SUBSTANCE (EPS) MATRIX
A FORMIDABLE ADVERSARY
The self-secreted EPS matrix of a biofilm establishes its functional and structural integrity and is considered the fundamental component that determines the physiochemical properties of a biofilm.14 In fact, just 10-20% of a wound biofilm is composed of microorganisms, with the other 80–90% comprising EPS.15
The EPS surrounds and encapsulates the individual bacteria within the EPS matrix, providing a highly adaptive, protective shield for the colony against mechanical and chemical attack. The majority of the resistance of the bacteria in a biofilm population is conveyed by the EPS matrix16, which creates a physical barrier obstructing the penetration of antimicrobials, thereby making it difficult for such treatments to reach the biofilm bacteria for eradication and removal.16, 17
To eliminate biofilm, treatments that focus on compromising the structural integrity of the EPS matrix to create an environment in which the bacteria within the EPS matrix are exposed for destruction and removal have proven more effective than antimicrobial treatments, as antimicrobials must first be able to overcome the challenge of reaching the bacteria in order to then alter its chemical processes to eliminate it.18
The majority of the resistance of the bacteria in a biofilm population is conveyed by the EPS.
The polymeric slime layer of the EPS creates a physical barrier impeding penetration of antimicrobials to reach the biofilm bacteria.
80-90% of a wound biofilm is comprised of the EPS.15