📘 Q7. IAS Prelims 2022 — Science & Technology (Biofilms)
🧷 Authentic Classroom Explanation by IAS Monk
📌 The Question
Consider the following statements:
- Biofilms can form on medical implants within human tissues.
- Biofilms can form on food and food processing surfaces.
- Biofilms can exhibit antibiotic resistance.
Which of the statements given above are correct?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
✅ Answer
(d)
🧑🏫 Classroom Explanation
Biofilms are structured communities of microorganisms (mainly bacteria) embedded in a self-produced matrix of extracellular polymeric substances (EPS). This matrix protects microbes and allows them to survive hostile environments.
- Statement 1 is correct:
Biofilms commonly form on medical implants such as catheters, prosthetic joints, heart valves, and stents. Once established, they are difficult to eliminate and can cause persistent infections. - Statement 2 is correct:
Biofilms develop on food and food-processing surfaces like pipes, cutting boards, and dairy equipment. They are a major concern in the food industry due to contamination risks and resistance to routine cleaning. - Statement 3 is correct:
Microorganisms within biofilms show enhanced antibiotic resistance. The EPS matrix restricts antibiotic penetration, and slow-growing cells inside biofilms are less susceptible to drugs.
Hence, all three statements are correct.
🔍 Curiosity Raiser
Why do biofilm-based infections often recur even after prolonged antibiotic treatment?
📚 Enrichment Notes
- Biofilms are found on:
- Medical devices
- Teeth (dental plaque)
- Industrial pipelines
- Water supply systems
- Biofilm resistance is due to:
- Physical barrier of EPS matrix
- Altered gene expression
- Presence of dormant “persister” cells
- Biofilms are a key reason behind hospital-acquired infections (HAIs).
🪔 IAS Monk Whisper
“The greatest strength of microbes lies not in numbers, but in cooperation.”