What is a biofilm?

A biofilm is best defined as a complex aggregation of microorganisms that adhere to surfaces and to each other, forming structured communities. These communities are typically embedded within a self-produced matrix of extracellular polymeric substances (EPS), which helps to protect the microorganisms from environmental stressors, antimicrobial agents, and the host immune system. Biofilms can form on a variety of surfaces, including natural environments like rocks and sediments, as well as artificial surfaces like medical devices, pipes, and industrial equipment.

The structure of biofilms allows for an enhanced exchange of nutrients and genetic material among the microbial community, which contributes to increased resistance to antibiotics and other harmful substances. In many cases, biofilms exhibit distinct physiological and phenotypical characteristics that differ from their free-floating counterparts, which is crucial for understanding their role in health, disease, and environmental microbiology.