Acanthamoeba is a genus of amoebae that are commonly recovered from soil, fresh water, and other habitats.
The genus Acanthamoeba has two stages in its life cycle, the metabolically active trophozoite stage and a dormant, stress-resistant cyst stage. In nature, Acanthamoeba species are generally free-living bacterivores. However, they are also opportunistic pathogens able to cause serious and sometimes fatal infections in humans and other animals.
Acanthamoeba
Acanthamoeba encephalitis microscopy and molecular diagnostics: scale bar: 10 μm
An amoeba, often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopods. Amoebae do not form a single taxonomic group; instead, they are found in every major lineage of eukaryotic organisms. Amoeboid cells occur not only among the protozoa, but also in fungi, algae, and animals.
Clockwise from top right: Amoeba proteus, Actinophrys sol, Acanthamoeba sp., Nuclearia thermophila., Euglypha acanthophora, neutrophil ingesting bacteria.
Amoeba phagocytosis of a bacterium
Foraminifera have reticulose (net-like) pseudopods, and many species are visible with the naked eye
Neutrophil (white blood cell) engulfing anthrax bacteria