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Apicomplexa
The Apicomplexa (also called Apicomplexia) are a large phylum of parasitic alveolates. Most of them possess a unique form of organelle that comprises a type of non-photosynthetic plastid called an apicoplast, and an apical complex structure. The organelle is an adaptation that the apicomplexan applies in penetration of a host cell. The Apicomplexa are unicellular and spore-forming. All species are obligate endoparasites of animals, except '' Nephromyces'', a symbiont in marine animals, originally classified as a chytrid fungus. Motile structures such as flagella or pseudopods are present only in certain gamete stages. The Apicomplexa are a diverse group that includes organisms such as the coccidia, gregarines, piroplasms, haemogregarines, and plasmodia. Diseases caused by Apicomplexa include: * Babesiosis (''Babesia'') * Malaria (''Plasmodium'') * Cryptosporidiosis (''Cryptosporidium parvum'') * Cyclosporiasis (''Cyclospora cayetanensis'') * Cystoisosporiasis (''Cystoisosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmodium
''Plasmodium'' is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of ''Plasmodium'' species involve development in a blood-feeding insect host which then injects parasites into a vertebrate host during a blood meal. Parasites grow within a vertebrate body tissue (often the liver) before entering the bloodstream to infect red blood cells. The ensuing destruction of host red blood cells can result in malaria. During this infection, some parasites are picked up by a blood-feeding insect (mosquitoes in majority cases), continuing the life cycle. ''Plasmodium'' is a member of the phylum Apicomplexa, a large group of parasitic eukaryotes. Within Apicomplexa, ''Plasmodium'' is in the order Haemosporida and family Plasmodiidae. Over 200 species of ''Plasmodium'' have been described, many of which have been subdivided into 14 subgenera based on parasite morphology and host range. Evolutionary relationships among different ''Pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gregarine
The gregarines are a group of Apicomplexan alveolates, classified as the Gregarinasina or Gregarinia. The large (roughly half a millimeter) parasites inhabit the intestines of many invertebrates. They are not found in any vertebrates. However, gregarines are closely related to both ''Toxoplasma'' and ''Plasmodium'', which cause toxoplasmosis and malaria, respectively. Both protists use protein complexes similar to those that are formed by the gregarines for gliding motility and invading target cells. This makes them excellent models for studying gliding motility with the goal of developing treatment options for toxoplasmosis and malaria. Thousands of different species of gregarines are expected to be found in insects, and 99% of these gregarines still need to be described. Each insect can be the host of multiple species. One of the most studied gregarines is ''Gregarina garnhami''. In general, gregarines are regarded as very successful parasites, as their hosts are spread over the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gregarinia
The gregarines are a group of Apicomplexan alveolates, classified as the Gregarinasina or Gregarinia. The large (roughly half a millimeter) parasites inhabit the intestines of many invertebrates. They are not found in any vertebrates. However, gregarines are closely related to both ''Toxoplasma'' and ''Plasmodium'', which cause toxoplasmosis and malaria, respectively. Both protists use protein complexes similar to those that are formed by the gregarines for gliding motility and invading target cells. This makes them excellent models for studying gliding motility with the goal of developing treatment options for toxoplasmosis and malaria. Thousands of different species of gregarines are expected to be found in insects, and 99% of these gregarines still need to be described. Each insect can be the host of multiple species. One of the most studied gregarines is ''Gregarina garnhami''. In general, gregarines are regarded as very successful parasites, as their hosts are spread over the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gregarinasina
The gregarines are a group of Apicomplexan alveolates, classified as the Gregarinasina or Gregarinia. The large (roughly half a millimeter) parasites inhabit the intestines of many invertebrates. They are not found in any vertebrates. However, gregarines are closely related to both ''Toxoplasma'' and ''Plasmodium'', which cause toxoplasmosis and malaria, respectively. Both protists use protein complexes similar to those that are formed by the gregarines for gliding motility and invading target cells. This makes them excellent models for studying gliding motility with the goal of developing treatment options for toxoplasmosis and malaria. Thousands of different species of gregarines are expected to be found in insects, and 99% of these gregarines still need to be described. Each insect can be the host of multiple species. One of the most studied gregarines is ''Gregarina garnhami''. In general, gregarines are regarded as very successful parasites, as their hosts are spread over the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haemogregarine
''Adeleorina'' is a suborder of parasites in the phylum Apicomplexa. History Léger proposed this taxon in 1911. The first species identified was '' Dactylosoma ranarum'' by Lankester (1871) in a frog in Europe. It was initially called ''Undulina ranarum'', but this was changed in 1882 to ''Drepanidium ranarum''. This species was subsequently moved to the genus ''Dactylosoma''. Canine hepatozoonosis was first described in India in 1905 by James. The organism was named ''Leukocytozoon canis''. The vector was identified in 1907 by Christopher to be the brown dog tick (''Rhipicephalus sanguineus''). The genus '' Hepatozoon'' was created by Miller in 1908 for a parasite of the white rat (''Rattus norvegicus'') that underwent merogony in the liver and sporogony in the mite '' Laelap echidinus''. Ledger initially placed this genus in the family Haemogregarinidae, but Wenyon subsequently removed it and placed it in the newly created taxon Hepatozoidae in 1926. Life cycle All species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apicoplast
An apicoplast is a Synapomorphy, derived non-photosynthetic plastid found in most Apicomplexa, including ''Toxoplasma gondii'', and ''Plasmodium falciparum'' and other ''Plasmodium'' spp. (parasites causing malaria), but not in others such as ''Cryptosporidium''. It originated from algae through secondary endosymbiosis; there is debate as to whether this was a Green algae, green or Red algae, red alga. The apicoplast is surrounded by four membranes within the outermost part of the endomembrane system. The apicoplast hosts important metabolic pathways like fatty acid synthesis, isoprenoid precursor synthesis and parts of the heme biosynthetic pathway. Significance Apicoplasts are a Relict (biology), relict, nonphotosynthetic plastid found in most protozoan parasites belonging to the phylum Apicomplexa. Among the most infamous Apicomplexan parasites is ''Plasmodium falciparum'', a causative agent of severe malaria. Because apicoplasts are vital to parasite survival, they provide an en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piroplasm
Piroplasmida is an order of parasites in the phylum Apicomplexa. They divide by binary fission and as sporozoan parasites they possess sexual and asexual phases (sexual reproduction occurs in the tick gut). They include the tick parasites ''Babesia'' and ''Theileria''. Description They are minute rounded or pyriform parasites found within erythrocytes, or other circulating or endothelial cells of vertebrates, where they reproduce by merogony. The trophozoite stage is separated from erythrocyte by a single membrane. This distinguishes them from other blood parasites that usually have at least two membranes. An apical complex with a polar ring and rhopteries occurs, but without a conoid and usually without associated pellicular microtubules. They lack flagella and do not form either oocysts or spores. The known vectors are ticks or leeches in which they undergo sporogony; sexual reproduction probably occurs in the vector. See also * Babesiosis Babesiosis or piroplasmos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conoidasida
Conoidasida is a class of parasitic alveolates in the phylum Apicomplexa. The class was defined in 1988 by Levine and contains two subclasses – the coccidia and the gregarines. All members of this class have a complete, hollow, truncated conoid. Gregarines tend to parasitize invertebrates with the mature gamonts being extracellular, the coccidia mostly infect vertebrates and have intracellular gamonts. Description A conoid is found in most species and when present forms complete but truncated cone. Sexual and asexual reproduction are present in life cycle of all species. Each zygote normally forms an oocyst wall within which it undergoes meiosis. This is sometimes followed by mitosis. This process of sporogony produces mobile vermiform infectious sporozoites. Multiple mitotic divisions ( schizogony) also occur during merogony of the feeding stages (trophozoites) and during gametogony. Motility Microgametes of some species are flagellated. Locomotion of other gametes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nephromyces
''Nephromyces'' is a genus of apicomplexans that are symbionts of the ascidian genus ''Molgula'' (sea grapes). Systematics ''Nephromyces'' was first described in 1888 by Alfred Mathieu Giard as a chytrid fungus, because of its filamentous cells. He formally named three species, each corresponding to a different species of the host animal. Molecular phylogenetics later showed that ''Nephromyces'' are not actually fungi, but instead constitute a group within the Apicomplexa that is related to the Piroplasmida. Species of ''Nephromyces'' * ''Nephromyces molgularum'' Giard, 1888 * ''Nephromyces rosocovitanus'' Giard, 1888 * ''Nephromyces sorokini'' Giard, 1888 Description ''Nephromyces'' is found in the lumen of the renal sac of its host animals. The renal sac is a closed, fluid-filled structure that is derived from the epicardium during development. There are different cell types (at least seven in ''Nephromyces'' from ''Molgula manhattensis'') which appear to be different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Babesia
''Babesia'', also called ''Nuttallia'', is an apicomplexan parasite that infects red blood cells and is transmitted by ticks. Originally discovered by the Romanian bacteriologist Victor Babeș in 1888, over 100 species of ''Babesia'' have since been identified. ''Babesia'' comprises more than 100 species of tick-borne parasites that infect erythrocytes (red blood cells) in many vertebrate hosts. ''Babesia'' species infect livestock worldwide, wild and domestic vertebrate animals, and occasionally humans, where they cause the disease babesiosis. In the United States, ''B. microti'' is the most common strain of the few which have been documented to cause disease in humans. Classification ''Babesia'' is a protozoan parasite found to infect vertebrate animals, mostly livestock mammals and birds, but also occasionally humans. Common names of the disease that ''Babesia microti'' causes are Texas cattle fever, redwater fever, tick fever, and Nantucket fever. The disease it caus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptosporidiosis
Cryptosporidiosis, sometimes informally called crypto, is a parasitic disease caused by ''Cryptosporidium'', a genus of protozoan parasites in the phylum Apicomplexa. It affects the distal small intestine and can affect the respiratory tract in both immunocompetent (i.e., individuals with a normal functioning immune system) and immunocompromised (e.g., persons with HIV/AIDS or autoimmune disorders) individuals, resulting in watery diarrhea with or without an unexplained cough. In immunosuppressed individuals, the symptoms are particularly severe and can be fatal. It is primarily spread through the fecal-oral route, often through contaminated water; recent evidence suggests that it can also be transmitted via fomites contaminated with respiratory secretions. ''Cryptosporidium'' is commonly isolated in HIV-positive patients presenting with diarrhea. Despite not being identified until 1976, it is one of the most common waterborne diseases and is found worldwide. The infection beg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmodiidae
The Plasmodiidae are a family (biology), family of apicomplexan parasites, including the type genus ''Plasmodium'', which is responsible for malaria. This family was erected in 1903 by Mesnil and is one of the four families in the Order (biology), order Haemospororida. Diagnostic criteria The diagnostic criteria of the Plasmodiidae are: * Macrogametes and microgamonts develop independently * Meiosis is absent * Microgametocyte produces eight flagellated microgametes * Zygote is motile (known as an ookinete) * Conoid present in ookinete stage only * Sporozoites naked in oocyst (that is without a Apicomplexa lifecycle stages, sporocyst) * Sporozoites have three walls * Heteroxenous: Protozoal merogony, merogony and Apicomplexan life cycle#gametogony, gamogony occur in vertebrate host, and fertilization and sporogony in definitive host (a blood-sucking insect) * Hemozoin pigment is produced Taxonomy The family Plasmodiidae has three sister taxa in the order Haemospororida: the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
