Q. Consider the following statements:

1. Biofilms can form on medical implants within human tissues.
2. Biofilms can form on food and food processing surfaces.
3. Biofilms can exhibit antibiotic resistance.

Which of the statements given above are correct? (UPSC Prelims 2022)
Answer: 1, 2 and 3
Notes: The correct answer is [D] 1, 2 and 3. Biofilms are a collective of one or more types of microorganisms that can grow on many different surfaces.

• Statement 1 – Correct: Biofilms are a major concern in healthcare as they can form on medical implants such as catheters, heart valves, and joint prostheses. Once formed, they are difficult to eradicate and can cause chronic infections within human tissues.
• Statement 2 – Correct: In the food industry, biofilms can form on various surfaces including stainless steel, plastics, and rubber used in food processing. These serve as a source of persistent contamination, potentially leading to food spoilage and the transmission of foodborne pathogens.
• Statement 3 – Correct: Microorganisms within a biofilm exhibit significantly higher resistance to antibiotics compared to their free-floating (planktonic) counterparts. The extracellular matrix of the biofilm acts as a physical barrier, and the altered metabolic state of the bacteria inside makes them less susceptible to traditional antimicrobial treatments.

Biofilms are characterized by an extracellular polymeric substance (EPS) matrix, which protects the internal community from environmental stressors, including the host immune system and chemical disinfectants.