Biofilms

Biofilms (pronounced: /ˈbʌɪoʊˌfɪlmz/) are complex, self-organized communities of microorganisms that grow on surfaces. They are a major form of microbial life in which cells stick to each other on a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric substance (EPS).

Etymology

The term "biofilm" is derived from the Greek words "bios" meaning "life" and "film" meaning "a thin layer or coating". It was first used in the late 20th century to describe the thin layer of microorganisms that forms on surfaces in contact with water.

Formation

Biofilms form when bacteria adhere to surfaces in aqueous environments and begin to excrete a slimy, glue-like substance that can stick to all kinds of materials including metals, plastics, soil particles, medical implant materials and tissue. The formation of a biofilm begins with the attachment of free-floating microorganisms to a surface.

Characteristics

Biofilms are characterized by a number of distinct traits including structural heterogeneity, genetic diversity, complex community interactions, and an extracellular matrix of polymeric substances. This matrix protects the cells within it and increases their resistance to antibiotics, disinfectants, and the host immune system.

Medical relevance

Biofilms have a significant impact on human health. They are involved in a wide variety of microbial infections in the body, by one estimate 80% of all infections. Infectious processes in which biofilms have been implicated include common problems such as urinary tract infections, catheter infections, middle-ear infections, formation of dental plaque, gingivitis, coating contact lenses, and less common but more lethal processes such as endocarditis, infections in cystic fibrosis, and infections of permanent indwelling devices such as joint prostheses and heart valves.

Related terms

• Microorganism
• Extracellular polymeric substance (EPS)
• Antibiotics
• Disinfectants
• Urinary tract infections
• Catheter infections
• Middle-ear infections
• Dental plaque
• Gingivitis
• Endocarditis
• Cystic fibrosis

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