What are biofilms?

Biofilms are communities of microorganisms that adhere to surfaces and are embedded in a self-produced matrix of extracellular polymeric substances (EPS). This matrix allows the microorganisms within the biofilm to communicate, share nutrients, and protect themselves from environmental stresses and antimicrobial agents. Biofilms can develop on various surfaces, both biotic (such as tissues in living organisms) and abiotic (like medical devices or natural waterways).

In contrast to biofilms, other options describe different biological concepts. Single organism growth in isolation refers to the growth of individual microbial species without interaction with others, which is not characteristic of biofilms. Replicating viruses in a host cell refers specifically to the life cycle of viruses, where they hijack host cellular machinery to reproduce, which is distinctly different from the cooperative nature of biofilms. Isolated cell cultures in a laboratory involve the growth of cells under controlled conditions, but this does not involve the complex interactions and community behaviors seen in biofilms. Thus, understanding the definition and characteristics of biofilms is crucial for recognizing their significance in microbiology and health contexts.