Which of the following statements about biofilms is correct?

• A. Biofilms consist only of single, free-floating bacterial cells.
• B. Biofilms are communities of microorganisms that adhere to surfaces and are embedded in a self-produced extracellular matrix.
• C. Biofilms cannot contribute to antibiotic resistance.
• D. Biofilms are formed exclusively by viruses.

Answer: (B)

Verified step by step guidance

1. Understand the definition of a biofilm: Biofilms are structured communities of microorganisms that attach to surfaces and produce a protective extracellular matrix.
2. Recognize that biofilms are not composed of single, free-floating bacterial cells; instead, they are communities where cells are embedded in a matrix.
3. Know that biofilms can contribute to antibiotic resistance because the extracellular matrix and close cell proximity can protect microbes from antibiotics.
4. Identify that biofilms are formed by microorganisms such as bacteria and fungi, but not by viruses, which do not form biofilms.
5. Conclude that the correct statement is the one describing biofilms as communities of microorganisms adhering to surfaces and embedded in a self-produced extracellular matrix.