Psorosperm (from the Greek ψωρα itch and σπερμα seed) is a former name of a number of
parasitic protozoa
Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histo ...
that produce cystlike or sporelike structures in the tissue of hosts. The term is now essentially obsolete.
* Some that affect vertebrate hosts are now called
coccidia
Coccidia (Coccidiasina) are a subclass of microscopic, spore-forming, single-celled obligate intracellular parasites belonging to the apicomplexan class Conoidasida.
As obligate intracellular parasites, they must live and reproduce within an a ...
.
* Others, such as the cause of
pébrine
Pébrine, or "pepper disease," is a disease of silkworms, which is caused by protozoan microsporidian parasites, mainly ''Nosema bombycis'' and, to a lesser extent, ''Vairimorpha'', '' Pleistophora'' and '' Thelohania'' species. The parasites infe ...
in silkworms, are now recognized as
microsporidia
Microsporidia are a group of spore-forming unicellular parasites. These spores contain an extrusion apparatus that has a coiled polar tube ending in an anchoring disc at the apical part of the spore. They were once considered protozoans or prot ...
ns, and some are
myxosporidians.
* The genus ''
Psorospermium
''Psorospermium haeckeli'' (or ''Psorospermium haeckelii'') is a parasitic species.
References
Parasitic opisthokonts
Mesomycetozoea
{{Holozoa-stub ...
'' (which includes the species ''
Psorospermium haeckeli'') itself is a parasite of crayfishes, and belongs to an enigmatic group of unicellular organisms that some biologists think may be related to the common ancestors of animals and fungi.
J. Müller introduced the term in German (as ''Psorospermien'') in 1841.
Psorosperm was at one point believed to be the cause of
Darier's disease.
[F. J. Darier. De la psorospermose folliculaire végétante. Étude anatomo-pathologique d'une affection cutanée non décrite ou comprise dans le groupe des acnés sebacées, cornées, hypertrophiantes, des kératoses (ichtyoses) folliculaires, etc. Annales de dermatologie et de syphilographie, Paris, 1889, 10: 597-612.]
"Psorospermiasis" is classified under 136.4 in
ICD-9
The International Classification of Diseases (ICD) is a globally used diagnostic tool for epidemiology, health management and clinical purposes. The ICD is maintained by the World Health Organization (WHO), which is the directing and coordinating ...
.
References
Parasitic eukaryotes
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