Amoebae

Synonym

Amoebida.

Classification

Order of Protozoa (new phylum Amoebozoa).

General Information

Among the Sarcodina ( Rhizopoda), only the amoebae are of parasitological interest. Amoebae are characterized by the presence of an endo- and ectocytoplasm, and by their locomotion and reeding as consequences of the formation of pseudopodia ( Trichomonadida/Fig. 2). These family-specific formations originate from the outward flow of cytoplasm and push the cell membrane ahead in the direction of flow; amoebic stages cannot swim, but creep around the substratum or the intestine (or vessels) of a parasitized host. Some of the amoebae, however, may become flagellated during their life cycles (Fig. 1, page 73).

Figure 1

Developmental stages of two species from soil amoeba which (under undefined conditions) may become pathogenic to man. 1–3 Naegleria spp. (e.g., N. gruberi). 1 Cyst. 2 Amoeboid stage (probably infectious for man via the olfactory pathways) is able to produce a cyst wall. 3...