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a genus of protozoa comprising parasites of worldwide distribution, several species of which are pathogenic for humans. All species are morphologically indistinguishable, and therefore the organisms have usually been assigned to species and subspecies according to their geographic origin, the clinical syndrome they produce, and their ecologic characteristics. They have also been separated based on their tendency to cause visceral, cutaneous, or mucocutaneous leishmaniasis. In some classifications, Leishmania is grouped in four complexes comprising species and subspecies: L. donovani, L. tropica, L. mexicana, and L. viannia.
Leishmania brazilien´sis Leishmania viannia.
Leishmania donova´ni donova´ni a subspecies of the L. donovani complex causing the classic form of visceral leishmaniasis in India. It is transmitted by the sandfly Phlebotomus argentipes, with humans being the only major reservoir hosts. Called also L. donovani.
Leishmania ma´jor a species of the L. tropica complex, transmitted by Phlebotomus papatasi, causing the rural form of Old World cutaneous leishmaniasis. Called also L. tropica major.
Leishmania mexica´na a complex comprising the species and subspecies causing the New World form of cutaneous leishmaniasis in humans: L. m. mexicana, L. m. amazonensis, and L. pifanoi.
1. a complex comprising the species causing the Old World form of cutaneous leishmaniasis: L. tropica, L. major, and L. aethiopica.
2. a species of the L. tropica complex causing the urban form of Old World cutaneous leishmaniasis. It is found in Iran, Iraq, and India, transmitted by Phlebotomus sergenti; and in southern France, Italy and certain Mediterranean islands, transmitted by P. papatasi. Human to human transmission may also occur.
Leishmania vian´nia a taxonomic complex comprising the subspecies that cause mucocutaneous leishmaniasis in its various forms; all of the subspecies develop in the midgut, foregut, and hindgut of their sandfly vectors. Formerly called L. braziliensis.
Leishmania(lēsh-man'ē-ă), Avoid the mispronunciation līshmā'nē-ă.
A genus of digenetic, asexual, protozoan flagellates (family Trypanosomatidae) that occur as amastigotes in the macrophages of vertebrate hosts, and as promastigotes in invertebrate hosts and in cultures. Species are largely indistinguishable morphologically but may be distinguished by clinical manifestations, geographic distribution and epidemiology, developmental patterns of promastigotes in their sandfly hosts, virulence testing of clones in vivo, the effect of test sera on growth in culture, cross-immunity tests, and serotyping with promastigote excreted factors; strains also can be distinguished by various biochemical analyses and DNA sequencing. Such procedures have identified all recognized groups and confirmed the separation of New World leishmaniasis agents into two species complexes, Leishmania mexicana and Leishmania braziliensis.
[W. B. Leishman]
Leishmania/Leish·ma·nia/ (lēsh-ma´ne-ah) a genus of parasitic protozoa, including several species pathogenic for humans. In some classifications, organisms are placed in four complexes comprising species and subspecies: L. donova´ni (causing visceral leishmaniasis), L. tro´pica (causing the Old World form of cutaneous leishmaniasis), L. mexica´na (causing the New World form of cutaneous leishmaniasis), and L. vian´nia (causing mucocutaneous leishmaniasis).
Etymology: William B. Leishman
a genus of protozoan parasites. These organisms are transmitted to humans by any of several species of sand flies.
A genus of digenetic, asexual, protozoan flagellates that occur as amastigotes in the macrophages of vertebrate hosts, and as promastigotes in invertebrate hosts and in cultures.
[W. B. Leishman]
leish·man·i·a, pl. leishmaniae (lēsh-man'ē-ă, -ē)
A member of the genus Leishmania.
LeishmaniaA genus of single-celled organisms equipped with a whip-like motility organ (flagellated protozoon). The genus contains many species responsible for the various forms of LEISHMANIASIS, known by such names as KALA AZAR, ESPUNDIA, forest yaws, chiclero ulcer, uta, diffuse cutaneous Leishmaniasis, oriental sore, Aleppo boil, Baghdad boil, bouton d'Orient and Delhi boil.
Leishman,Sir William Boog, Scottish surgeon, 1865-1926.
Leishmania - a genus of digenetic, asexual, protozoan flagellates.
Leishman chrome cells - basophilic granular leukocytes (basophils) observed in the circulating blood of some persons with blackwater fever.
Leishman stain - a polychromed eosin-methylene blue stain used in the examination of blood films.
Leishman-Donovan body - the intracytoplasmic, nonflagellated leishmanial form of certain intracellular parasites. Synonym(s): amastigote; L-D body
leishmaniasis - tropical disease that is spread by sandflies.
a genus of protozoan parasites transmitted by sandflies, which also act as intermediate hosts.
found in lizards and other mammals.
reservoir hosts are hyraxes.
Leishmania brasiliensis brasiliensis
reservoir hosts are forest rodents. Causes mucocutaneous leishmaniasis in humans.
Leishmania brasiliensis guyanensis
dogs are infected; in humans the disease is the cutaneous form in most cases.
Leishmania brasiliensis panamensis
reservoirs are sloths, kinkajous and many other forest animals.
causes visceral leishmaniasis in humans and dogs.
causes visceral leishmaniasis in humans and in carnivores.
causes cutaneous leishmaniasis in guinea pigs.
causes visceral leishmaniasis in dogs and other carnivores. In humans it is children who are most commonly affected.
dogs and bush mammals are reservoir hosts. In humans this is the cause of oriental sore, the important cutaneous form of the disease.
Leishmania mexicana amazonensis
causes cutaneous leishmaniasis in humans. Rodents and bush animals are reservoir hosts.
Leishmania mexicana mexicana
reservoir hosts are rodents; causes cutaneous leishmaniasis in humans.
Leishmania mexicana pifanoi
causes chronic cutaneous leishmaniasis in humans.
causes cutaneous leishmaniasis in humans; probably infests dogs.
causes cutaneous leishmaniasis in humans and dogs.