Consider the following statements : 1. Biofilms can form on medical implants within human tissues. 2. Biofilms can form on food and food processing surface

1. A. 1 and 2 only
2. B. 2 and 3 only
3. C. 1 and 3 only
4. D. 1, 2 and 3

Answer: D

Explanation

Biofilm is a thin usually resistant layer of microorganisms (as bacteria) that forms on and coats various surfaces (as of catheters or water pipes). These cells are frequently embedded within a self- produced matrix of extracellular polymeric substance (EPS). Biofilms can form on just about any imaginable surface: metals, plastics, natural materials (such as rocks), medical implants, kitchen counters, contact lenses, the walls of a hot tub or swimming pool, human and animal tissue, including medical devices and implants. Hence statement 1 is correct. They are a constant concern in food processing environments. Biofilms of Lactobacillus curvatus could lead to a defect caused by the formation of calcium lactate crystals in Cheddar cheese and they can be present on equipment surfaces (tough to remove). Hence statement 2 is correct. Bacteria form biofilms, a kind of matrix, during infection in plants and animals. The biofilm shields the bacteria from antibiotics and helps bacteria survive harsh conditions such as extreme temperature or stress. Thus they can exhibit antibiotic resistance. Hence statement 3 is correct.