The phylum Microsporidia is a group of obligate intracellular single‐celled parasites of animals; some are species‐specific, whereas others appear to have a broader host range. A few Microsporidia are clinically important as opportunistic parasites of immunocompromised humans.

Keywords: emerging disease; sporont; polar filament; encephalitozoon; insect parasite

Figure 1.

Electron micrograph of Amblyospora abserati. Courtesy of Theodore Andreadis.

Figure 2.

Microsporidial features, based on those of Amblyospora species (Figure ).

Figure 3.

Nosema/Vairimorpha life cycle.

Figure 4.

Pleistophora life cycle.

Figure 5.

Amblyospora life cycle.

Figure 6.

Phylogeny of Microsporidia based on comparative rDNA sequence analysis. H, Reported from humans.



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Further Reading

Canning EU and Lom J (1986) The Microsporidia of Vertebrates. London: Academic Press.

Dawes B (1998) Advances in Parasitology; Opportunistic Protozoa in Humans. Part 2 Enterocytozoon bieneusi and other Microsporidia. 40: 281–385.

Issi IV (1986) Microsporidia. In: Beyer TV (ed.) Academy of Sciences of the USSR, Society of Protozoologists of the USSR, Series Protozoology, No. 10.

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Larsson RJI (1988) Identification of microsporidian genera (Protozoa, Microspora): a guide with comments on the taxonomy. Archiv für Protistenkunde 136: 1–37.

Sprague V (1976) Systematics of the Microsporidia. In: Bulla LA and Cheng TC (eds) Comparative Pathobiology, vol. 2. New York: Plenum Press.

Sprague V and Becnel JJ (1992) Taxonomy of phylum Microspora. Critical Reviews in Microbiology 18: 285–395.

Wittner M and Weiss LM (eds) (1999) The Microsporidia and Microsporidiosis. Washington, DC: ASM Press.

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Vossbrinck, Charles R(Jun 2001) Microsporidians. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0001982]