Psorosperm (from the Greek ψωρα itch and σπερμα seed) is a former name of a number of
parasitic
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...
protozoa 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 ...
.
* 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 i ...
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 pr ...
ns, and some are
myxosporidia
Myxosporea is a class of microscopic parasites, belonging to the Myxozoa clade within Cnidaria. They have a complex life cycle which comprises vegetative forms in two hosts, an aquatic invertebrate (generally an annelid but sometimes a bryozoan) ...
ns.
* 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
Darier's disease (DAR) is an inherited skin disorder that presents with multiple greasy, crusting, thick brown bumps that merge into patches.
It is an autosomal dominant disorder discovered by French dermatologist Ferdinand-Jean Darier. Darier's ...
.
[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 coordinatin ...
.
References
Parasitic eukaryotes
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