- A protozoan phylum that includes the genus Nosema and Encephalitozoon, and is characterized by the presence of unicellular spores with an imperforate wall and an extrusion apparatus having a polar tube and a polar cap; mitochondria are absent. They are intracellular parasites of invertebrates and lower vertebrates, with rare examples in higher vertebrates. SYN: Cnidospora. [micro- + G. sporos, seed]
* * *microspora pl of MICROSPORUM
* * *Mi·cros·po·ra (mi-krosґpə-rə) [micro- + spore] a phylum of protozoa found as obligatory intracellular parasites in nearly all major animal groups, being especially common in insects, sometimes causing economically important disease. The spore phase is characterized by the presence of minute unicellular spores, each with an imperforate wall containing one nucleus or a dinucleate sporoplasm and a simple or complex extrusion apparatus with a polar tube or polar cap always present; mitochondria are absent. It comprises two classes: Rudimicrosporea and Microsporea.
Medical dictionary. 2011.