Answer to Case 542

Answer to Parasite Case of the Week 542: Acanthamoeba sp. trophozoite and cysts

The free-living amebae, Acanthamoeba species and Naegleria fowleri (but not Balamuthia mandrillaris) can be grown on non-nutrient agar overlain with bacteria to provide a food source for the organisms. In this case, the presence of a characteristic double-walled cyst and trophozoite, along with the source (corneal scrapings) allow us to identify this ameba as an Acanthamoeba species.

We sadly did away with our free-living amebae culture a while back and replaced it with a multiplex real-time PCR assay. It's faster than culture, while providing equal sensitivity, so it is better for patient care. However, I do miss seeing these cool organisms grow in culture!