For Acanthamoeba culture, which medium is considered the standard?

• A. Blood agar
• B. Sabouraud dextrose agar
• C. Non-nutrient agar with heat-killed E. coli
• D. Thayer Martin agar

Answer: (C)

Acanthamoeba is cultured on a surface that provides a simple environment and a defined food source, because this protozoan feeds on bacteria rather than requiring rich nutrients. Non-nutrient agar gives a clean, unnutrient surface, and a lawn of Escherichia coli supplies the food the amoebae graze on as they move, form trophozoites, and eventually cysts. Using heat-killed E. coli helps keep the plate stable by reducing unintended bacterial overgrowth, while still providing the necessary microbial foothold for the amoebae. Other media like blood agar, Sabouraud dextrose agar, or Thayer Martin are designed for bacteria, fungi, or specific pathogens and don’t support the characteristic growth pattern used to identify Acanthamoeba. So the standard medium is non-nutrient agar with heat-killed E. coli.