Plasmodium vaughani
Encyclopedia
Plasmodium vaughani is a parasite of the genus Plasmodium
subgenus Novyella
.
Like all Plasmodium species P. vaughani has both vertebrate
and insect
hosts. The vertebrate hosts for this parasite are bird
s.
The length of the asexual cycle is 24 hours.
Trophozoites: Ring forms are unusual. The trophozoite is usually irregular in outline. The nucleus is small and there may be a single clear outgrowth of the cytoplasm. One ot two small pigment granules may be seen. These forms are found in mature and polychromatic erythrocytes.
Schizonts: These are usually found in a polar or sub polar position within the host cell but may be found anywhere within the cell. They are found in mature or polychromatic erthrocytes. Mature forms measure 2.3 to 5.4 micrometres in width and 1.5 to 4.4 micrometres in length. They are irregular in shape but tend to be round or ovoid. Within each schizont are 4-8 merozoites. These are usually arranged in a fan like fashion but may occur at random. A transparent globule may be present along with one to three pigment granules. The host nucleus is not normally displaced.
Gametocytes: The macro- and microgametocytes are very similar except for size in this species. They are elongated, possess 2-24 (usually 10) pigment granules which may be found in clumps and are usually found in mature erythrocytes. The nucleus is pale, compact and central in position. The gametocyte usually lies along the host cell nucleus but young gametoctyes may adhere to the host cell membrane. The host nucleus is not normally displaced. They are 8.0 to 13.7 micrometres in length and 1.2 to 2.8 micrometres in width.
Asexual replication appears to occur in three ways:
(1) by repeated binary fission of the chromatin with eventual splitting of the cytoplasm
(2) by the splitting of an elongate parasite into merozoites having a bead-like arrangement
(3) by the similar breaking-up of a ring-shaped form with a resulting ring of merozoites
This species is found in Alaska
, Arkansas
, Brazil
, Bulgaria
, Colombia
, New Hebrides
, New Brunswick
, Nigeria
and Pakistan
.
species).
Plasmodium
Plasmodium is a genus of parasitic protists. Infection by these organisms is known as malaria. The genus Plasmodium was described in 1885 by Ettore Marchiafava and Angelo Celli. Currently over 200 species of this genus are recognized and new species continue to be described.Of the over 200 known...
subgenus Novyella
Novyella
Novyella is a subgenus of the genus Plasmodium - all of which are parastic protozoa. The subgenus was created in 1963 by created by Corradetti et al.. Species in this subgenus infect birds...
.
Like all Plasmodium species P. vaughani has both vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
and insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
hosts. The vertebrate hosts for this parasite are bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s.
Description
The parasite was first described by Novy & MacNeal in 1904.The length of the asexual cycle is 24 hours.
Trophozoites: Ring forms are unusual. The trophozoite is usually irregular in outline. The nucleus is small and there may be a single clear outgrowth of the cytoplasm. One ot two small pigment granules may be seen. These forms are found in mature and polychromatic erythrocytes.
Schizonts: These are usually found in a polar or sub polar position within the host cell but may be found anywhere within the cell. They are found in mature or polychromatic erthrocytes. Mature forms measure 2.3 to 5.4 micrometres in width and 1.5 to 4.4 micrometres in length. They are irregular in shape but tend to be round or ovoid. Within each schizont are 4-8 merozoites. These are usually arranged in a fan like fashion but may occur at random. A transparent globule may be present along with one to three pigment granules. The host nucleus is not normally displaced.
Gametocytes: The macro- and microgametocytes are very similar except for size in this species. They are elongated, possess 2-24 (usually 10) pigment granules which may be found in clumps and are usually found in mature erythrocytes. The nucleus is pale, compact and central in position. The gametocyte usually lies along the host cell nucleus but young gametoctyes may adhere to the host cell membrane. The host nucleus is not normally displaced. They are 8.0 to 13.7 micrometres in length and 1.2 to 2.8 micrometres in width.
Asexual replication appears to occur in three ways:
(1) by repeated binary fission of the chromatin with eventual splitting of the cytoplasm
(2) by the splitting of an elongate parasite into merozoites having a bead-like arrangement
(3) by the similar breaking-up of a ring-shaped form with a resulting ring of merozoites
Geographical occurrence
This species is second only to Plasmodium relictum in its frequency of occurrence.This species is found in Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
, Arkansas
Arkansas
Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
, Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, Bulgaria
Bulgaria
Bulgaria , officially the Republic of Bulgaria , is a parliamentary democracy within a unitary constitutional republic in Southeast Europe. The country borders Romania to the north, Serbia and Macedonia to the west, Greece and Turkey to the south, as well as the Black Sea to the east...
, Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, New Hebrides
New Hebrides
New Hebrides was the colonial name for an island group in the South Pacific that now forms the nation of Vanuatu. The New Hebrides were colonized by both the British and French in the 18th century shortly after Captain James Cook visited the islands...
, New Brunswick
New Brunswick
New Brunswick is one of Canada's three Maritime provinces and is the only province in the federation that is constitutionally bilingual . The provincial capital is Fredericton and Saint John is the most populous city. Greater Moncton is the largest Census Metropolitan Area...
, Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
and Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
.
Clinical features and host pathology
Known hosts for this species include the warbler (Acrocephalus schoenobaenus), the blackbird (Agelaius phoenicius), the goldfinch (Carduelis carduelis), the blue jay (Cyanocitta cristata), the yellow warbler (Dendroica petechia), the robin (Erithacus rubecula), junco (Junco hyemalis hyemalis), the red-billed leiothrix (Leiothrix lutea), the bullfinch (Loxigilla violacea), house sparrow (Passer domesticus), the weaver (Ploceus cucullatus), the grackle (Quiscalus quiscula), the canary (Serinus canaria), the blackcap (Sylvia atricapilla), the pigeon (Streptopelia senegalensis), eastern meadowlark (Sturnella magna), starling (Sturnus vulgaris) black-faced grassquit (Tiaris bicolor), white-eyed thrush (Turdus jamaicensis), the blackbird (Turdus merula) and American sparrows (ZonotrichiaZonotrichia
Zonotrichia is a genus of five American sparrows of the family Emberizidae. Four of the species are North American, but the Rufous-collared Sparrow breeds in highlands from the extreme southeast of Mexico to Tierra del Fuego, and on Hispaniola....
species).
Subspecies
- P. vaughani merulae Corradetti and Scanga 1972
- P. vaughani tenue Laveran and Marullaz 1914
- P. vaughani vaughani Novy and MacNeal 1904