''Eimeria'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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. Th ...

n parasites that includes various species capable of causing the disease

coccidiosis Coccidiosis is a parasitic disease of the intestinal tract of animals caused by coccidian protozoa. The disease spreads from one animal to another by contact with infected feces or ingestion of infected tissue. Diarrhea, which may become bloody i ...

in animals such as

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Adult females are referred to as cows and adult ...

poultry Poultry () are domesticated birds kept by humans for their eggs, their meat or their feathers. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes (which includes chickens, qu ...

and smaller

ruminant Ruminants (suborder Ruminantia) are hoofed herbivorous grazing or browsing mammals that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. The ...

s including

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticate ...

and

goat The goat or domestic goat (''Capra hircus'') is a domesticated species of goat-antelope typically kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the a ...

s. ''Eimeria'' species are considered to be

monoxenous Monoxenous development, or monoxeny, characterizes a parasite whose development is restricted to a single host species. The etymology of the terms monoxeny / monoxenous derives from the two ancient Greek words (), meaning "unique", and (), m ...

because the life cycle is completed within a single host, and stenoxenous because they tend to be host specific, although a number of exceptions have been identified. Species of this genus infect a wide variety of hosts. Thirty-one species are known to occur in bats (Chiroptera), two in turtles, and 130 named species infect fish. Two species (''E. phocae'' and ''E. weddelli'') infect seals. Five species infect llamas and alpacas: ''E. alpacae'', ''E. ivitaensis'', ''E. lamae'', ''E. macusaniensis'', and ''E. punonensis''. A number of species infect rodents, including ''E. couesii'', ''E. kinsellai'', ''E. palustris'', ''E. ojastii'' and ''E. oryzomysi''. Others infect poultry (''E. necatrix'' and ''E. tenella''), rabbits (''E. stiedai'') and cattle (''E. bovis'', ''E. ellipsoidalis'', and ''E. zuernii''). For full species list, see below. The most prevalent species of ''Eimeria'' that cause coccidiosis in cattle are ''E. bovis'', ''E. zuernii'', and ''E. auburnensis''. In a young, susceptible calf it is estimated that as few as 50,000 infective

oocysts Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism is ...

can cause severe disease. ''Eimeria'' infections are particularly damaging to the poultry industry and costs the United States more than $1.5 billion in annual loses. The most economically important species among poultry are ''E. tenella'', ''E. acervulina'', and ''E. maxima''. The oocysts of what was later called ''Eimeria stiedai'' were first seen by the pioneering Dutch microscopist

Antonie van Leeuwenhoek Antonie Philips van Leeuwenhoek ( ; ; 24 October 1632 – 26 August 1723) was a Dutch microbiologist and microscopist in the Golden Age of Dutch science and technology. A largely self-taught man in science, he is commonly known as " the ...

(1632–1723) in the

bile Bile (from Latin ''bilis''), or gall, is a dark-green-to-yellowish-brown fluid produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is produced continuously by the liver (liver bi ...

of a

rabbit Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit sp ...

in 1674. The genus is named after the German

zoologist Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and d ...

Theodor Eimer Gustav Heinrich Theodor Eimer (22 February 1843 – 29 May 1898) was a German zoologist. He was a popularizer of orthogenesis, a form of directed evolution through mutations that made use of Lamarckian principles. Life and work Eimer was born ...

(1843–1898).

Life cycle

The ''Eimeria'' life cycle has an

exogenous In a variety of contexts, exogeny or exogeneity () is the fact of an action or object originating externally. It contrasts with endogeneity or endogeny, the fact of being influenced within a system. Economics In an economic model, an exogen ...

phase, during which the oocysts are excreted into the environment, and an

endogenous Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, ...

phase, where parasite development occurs in the host intestine. During the endogenous phase, several rounds of

asexual reproduction Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the ...

, or schizogony take place, after which the

sexual differentiation Sexual differentiation is the process of development of the sex differences between males and females from an undifferentiated zygote. Sex determination is often distinct from sex differentiation; sex determination is the designation for the dev ...

gamete A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce ...

s and

fertilisation Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Pro ...

occurs. Parasite transmission occurs via the oral-fecal route. Infections are common in farming environments where many animals are confined in a small space. 450px, ''Eimeria'' life cycle

Oocysts

There are two forms of

oocyst Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism is ...

: sporulated or late oocyst, and unsporulated or early oocyst. An infected host releases oocysts into the environment in their unsporulated form. These contain a multi-layered cell wall making them highly resistant to environmental pressures. Once released, the unsporulated oocysts undergo

meiosis Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately ...

upon contact with oxygen and moisture. This process is known as

sporulation In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, ...

and the oocysts take approximately 2 to 7 days to become infectious. The sporulated oocyst is said to be tetrasporic meaning it contains four sporocysts, while each sporocyst is dizoic, i.e. it contains two sporozoites. Once ingested, the oocysts undergo a process called excystation, whereby thousands of sporozoites are released into lumen of the intestine. In the case of ''E. tenella'', this process is thought to occur due to the combination of enzymatic degradation and mechanical abrasion of the oocyst wall in the chicken's

gizzard The gizzard, also referred to as the ventriculus, gastric mill, and gigerium, is an organ found in the digestive tract of some animals, including archosaurs (pterosaurs, crocodiles, alligators, dinosaurs, birds), earthworms, some gastropods, so ...

Sporozoites

The motile sporozoites invade the

enterocyte Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells which line the inner surface of the small and large intestines. A glycocalyx surface coat contains digestive enzymes. Microvilli on the apical surface increase i ...

s of small intestine, and migrate to their respective sites of development. Invasion is mediated through specialised membrane-bound structures on the surface of the parasite that release secretions. This results in the recognition of, and attachment to host cell

receptor Receptor may refer to: *Sensory receptor, in physiology, any structure which, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds to a n ...

s. This process is known as

gliding motility Gliding motility is a type of translocation used by microorganisms that is independent of propulsive structures such as flagella, pili, and fimbriae. Gliding allows microorganisms to travel along the surface of low aqueous films. The mechanisms of ...

, which is conserved across all species of ''

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. Th ...

''. Membrane glyconjugates have been proposed as potential host cell receptors for ''Eimeria'' species. After invasion, the sporozoites develop into

trophozoite A trophozoite (G. ''trope'', nourishment + ''zoon'', animal) is the activated, feeding stage in the life cycle of certain protozoa such as malaria-causing ''Plasmodium falciparum'' and those of the ''Giardia'' group. (The complement of the trophozoi ...

s, then into schizonts, where they undergo several rounds of

. This results in many nuclei developing within the schizont. Each nucleus develops into a

merozoite Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism i ...

. Invasion requires the formation of a moving junction between parasite and host

cell membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (t ...

s. In ''E. tenella'', this involves parasite micronemes and rhoptry proteins including RON2, RON5 and AMA-2. It is unlikely that the host cell is completely passive in the invasion process, although evidence of host physical forces that assist in mediating parasite entry remains controversial.

Merozoites

When schizonts rupture, merozoites are released, which either go on to re-infect more

enterocytes Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells which line the inner surface of the small and large intestines. A glycocalyx surface coat contains digestive enzymes. Microvilli on the apical surface increase i ...

or develop into either male or female

gametes A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce ...

via the process of gametogenesis. These gametes fuse to form an oocyst, which is then released in its non-infectious, unsporulated form through the faeces of the host. Merozoite invasion also requires the formation of a moving junction, however the

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

s involved in this process differs from those on sporozoites. Rhoptry proteins AMA-1 and RON4 are found exclusively on merozoites. There is also a greater diversity of variant surface antigens found on the surface of merozoites. It is hypothesised that this may be due to the fact that merozoites are short-lived and a greater

antigen In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune respon ...

repertoire would permit faster binding and invasion.

Taxonomy

File : Apicomplexa tree..png, 350px, Evolutionary relationships among

The ''Eimeria'' lie within the family Eimeriidae. ''Eimeria'' accounts for close to 75% of the species within this family, and it is the most specious of the genera of the

with 1,700 described species. Attempts to subdivide this large taxonomic unit into separate genera have been made. The classification of eimeriid coccidian was largely based on morphological and life cycle details. More recently, classification has been done using rDNA and mitochondrial genes, which indicate ''Eimeria'' may be

paraphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In ...

to ''

Isospora ''Isospora'' is a genus of internal parasites in the subclass Coccidia. It is responsible for the condition isosporiasis, which causes acute, non-bloody diarrhoea in immunocompromised individuals. Taxonomy At least 248 species were originall ...

'' and ''

Cyclospora ''Cyclospora'' is a genus of apicomplexan parasites. It includes the species ''Cyclospora cayetanensis'', the causative agent of cyclosporiasis. Members of ''Cyclospora'' are characterized as having oocysts with two sporocysts, each containing ...

'' ''Eimeria'': These species are tetrasporocystic with dizoic, nonbivalved sporocysts with or without Stieda bodies. This new genus retains the majority of the species. '' Goussia'' (Labbe 1896): These species are tetrasporocystic, dizoic, lack Stieda bodies, and have sporocyst walls consisting of two valves joined by a longitudinal suture. This genus contains about 20 species. ''

Crystallospora ''Crystallospora'' is a genus of Apicomplexa in the family Aggregatidae. History The genus ''Crystallospora'' was created by Labbé in 1896Labbe A (1896) Recherches Zoologiques, Cytologiques et Biologiques sur les Coccidies. Archives de Zoolog ...

'' (Thelohan 1893): The species in this genus is tetrasporocystic and dizoic, and have dodecahedral sporocysts composed of two hexagonal, pyrimidal valves joined at their bases by a suture. This genus contains a single species, ''Crystallospora cristalloides'' '' Epieimeria'': The species in this genus are tetrasporocystic, dizoic, possess Stieda bodies, and undergo merogony and gametogony on the lumenal surface of the intestinal tract. Three species are in this genus.

Species identification

Methods for species identification are varied and among others, include isozyme analysis, the use of

rRNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribos ...

and rDNA probes, DNA

assay An assay is an investigative (analytic) procedure in laboratory medicine, mining, pharmacology, environmental biology and molecular biology for qualitatively assessing or quantitatively measuring the presence, amount, or functional activity of ...

s and

recombinant DNA Recombinant DNA (rDNA) molecules are DNA molecules formed by laboratory methods of genetic recombination (such as molecular cloning) that bring together genetic material from multiple sources, creating sequences that would not otherwise be f ...

techniques. PCR has proven most useful for

outbreak In epidemiology, an outbreak is a sudden increase in occurrences of a disease when cases are in excess of normal expectancy for the location or season. It may affect a small and localized group or impact upon thousands of people across an entire ...

surveillance. Prior to these methods, species identification was based on

phenotypic In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological pr ...

characteristics such as the site of parasite development, the oocyst structure, the host species, cross

immunity Immunity may refer to: Medicine * Immunity (medical), resistance of an organism to infection or disease * ''Immunity'' (journal), a scientific journal published by Cell Press Biology * Immune system Engineering * Radiofrequence immunity de ...

and the presence of lesions. Out of these, comparing oocyst structures was the most commonly used method.

Genomics

whole genome sequencing Whole genome sequencing (WGS), also known as full genome sequencing, complete genome sequencing, or entire genome sequencing, is the process of determining the entirety, or nearly the entirety, of the DNA sequence of an organism's genome at a ...

project is in progress with chosen species, ''Eimeria tenella''. The genome is about 60

megabases A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...

in size and has a

GC-content In molecular biology and genetics, GC-content (or guanine-cytosine content) is the percentage of nitrogenous bases in a DNA or RNA molecule that are either guanine (G) or cytosine (C). This measure indicates the proportion of G and C bases out ...

around 53%. The 14

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins ar ...

s range in size from 1 to > 6 megabases. Since 2013, the sequencing and annotation of a further six avian ''Eimeria'' species genomes is in progress.

Pathology and symptoms

Coccidiosis typically results in

diarrhoea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...

, weight loss and

dehydration In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...

. A combination of these factors may result in poor growth and death of the animal, particularly amongst young. Other clinical signs include

lethargy Lethargy is a state of tiredness, sleepiness, weariness, fatigue, sluggishness or lack of energy. It can be accompanied by depression, decreased motivation, or apathy. Lethargy can be a normal response to inadequate sleep, overexertion, overwo ...

, depression, and reduced normal grooming behaviour. Diarrhoea may be bloody due to

intestinal epithelium The intestinal epithelium is the single cell layer that form the luminal surface (lining) of both the small and large intestine (colon) of the gastrointestinal tract. Composed of simple columnar epithelial cells, it serves two main functi ...

dying off when a large number of oocysts and merozoites burst out of the cells. The severity of the disease is directly dependent on the number of infective ''Eimeria'' oocysts that are ingested. The

pathogenesis Pathogenesis is the process by which a disease or disorder develops. It can include factors which contribute not only to the onset of the disease or disorder, but also to its progression and maintenance. The word comes from Greek πάθος ''pat ...

of infection varies from mild to severe, and is largely dependent on the magnitude of infection. In light infections, the damage to the gut might only be minimal and be rapidly repaired as cells are rapidly replaced by the body. However, in heavy infections, it may only take two weeks for many intestinal epithelial cells to be infected with either ''Eimeria'' meronts or gametocytes. These cause the epithelial cells to burst, which causes significant damage to the intestine epithelial layer, resulting in the release of blood, fluid, and

electrolyte An electrolyte is a medium containing ions that is electrically conducting through the movement of those ions, but not conducting electrons. This includes most soluble salts, acids, and bases dissolved in a polar solvent, such as water. Upon ...

s into the intestine.

Prevention and treatment

Good

animal husbandry Animal husbandry is the branch of agriculture concerned with animals that are raised for meat, fibre, milk, or other products. It includes day-to-day care, selective breeding, and the raising of livestock. Husbandry has a long history, starti ...

practices and prophylactic application of anticoccidial drugs that target different stages of the parasite lifecycle, such as

sulfonamide In organic chemistry, the sulfonamide functional group (also spelled sulphonamide) is an organosulfur group with the structure . It consists of a sulfonyl group () connected to an amine group (). Relatively speaking this group is unreactive. ...

s, ionophores and

toltrazuril Toltrazuril is a coccidiostat. See also * Clazuril * Diclazuril Diclazuril (trade name Vecoxan) is a coccidiostat. See also * Clazuril * Ponazuril * Toltrazuril References Antiparasitic agents Nitriles Chlorobenzenes Triaz ...

, are the preferred methods of disease prevention, particularly in the poultry industry. The following drugs can be used for treatment of coccidiosis in cattle: amprolium, sulfaquinoxaline, and sulfamethazine. However, it is often more effective to prevent this disease in cattle, which can be aided by the products lasalocid, decoquinate, and

monensin Monensin is a polyether antibiotic isolated from '' Streptomyces cinnamonensis''. It is widely used in ruminant animal feeds. The structure of monensin was first described by Agtarap et al. in 1967, and was the first polyether antibiotic to have ...

. There is a growing problem of

drug resistance Drug resistance is the reduction in effectiveness of a medication such as an antimicrobial or an antineoplastic in treating a disease or condition. The term is used in the context of resistance that pathogens or cancers have "acquired", that is ...

, as well as possible drug residues in the meat once the animal is butchered. As a result, other avenues of control are being explored, particularly vaccine development, although several live attenuated vaccines have been in use since the 1950s. So far, the best practice is to vaccinate the chicks once they hatch from the egg so they are immune for life. Infection with ''Eimeria'' results in life-long

to that particular parasite species, but does not give cross protection against other species. For these reasons, vaccines for control seem promising, of which live attenuated vaccines are most effective. However, the search for highly immunogenic

s and overcoming antigenic variation of the parasites remains a challenge. Immunity to the parasite varies depending on parasite and host species, as well as the site of invasion. CD4+ T cells and

interferon gamma Interferon gamma (IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. Wheelock ...

(γ) are crucial components of

natural immunity In biology, immunity is the capability of multicellular organisms to resist harmful microorganisms. Immunity involves both specific and nonspecific components. The nonspecific components act as barriers or eliminators of a wide range of pathoge ...

to infection.

Humoral immunity Humoral immunity is the aspect of immunity that is mediated by macromolecules - including secreted antibodies, complement proteins, and certain antimicrobial peptides - located in extracellular fluids. Humoral immunity is named so because it i ...

is thought to play little role in protection, and is most likely mediated through secretory

IgA Iga may refer to: Arts and entertainment * Ambush at Iga Pass, a 1958 Japanese film * Iga no Kagemaru, Japanese manga series * Iga, a set of characters from the Japanese novel '' The Kouga Ninja Scrolls'' Biology * ''Iga'' (beetle), a g ...

antibodies.

Host-parasite relations

Fish

* ''Eimeria aurati'' -

goldfish The goldfish (''Carassius auratus'') is a freshwater fish in the family Cyprinidae of order Cypriniformes. It is commonly kept as a pet in indoor aquariums, and is one of the most popular aquarium fish. Goldfish released into the wild have bec ...

(''Carassius auratus'') * ''Eimeria baueri'' -

crucian carp The crucian carp (''Carassius carassius'') is a medium-sized member of the common carp family Cyprinidae. It occurs widely in northern European regions. Its name derives from the Low German ''karusse'' or ''karutze'', possibly from Medieval La ...

(''Carassius carassius'') * ''Eimeria lepidosirenis'' -

South American lungfish The South American lungfish (''Lepidosiren paradoxa'') is the single species of lungfish found in swamps and slow-moving waters of the Amazon, Paraguay, and lower Paraná River basins in South America. Notable as an obligate air-breather, it is ...

(''Lepidosiren paradoxa'') * ''Eimeria leucisci'' - common barbel (''Barbus barbus bocagei'') * ''Eimeria rutili'' - European chub (''Leuciscus cephalus cabeda''),

Iberian nase The Iberian nase (''Pseudochondrostoma polylepis'') is a species of freshwater fish in the family Cyprinidae. It is found in Portugal and in Spain. Its natural habitats are river A river is a natural flowing watercourse, usually freshwa ...

(''Chondrostoma polylepis polylepis'') * ''Eimeria vanasi'' - blue tilapia (''

Oreochromis aureus The blue tilapia (''Oreochromis aureus'') is a species of tilapia, a fish in the family Cichlidae. Native to Northern and Western Africa, and the Middle East, through introductions it is now also established elsewhere, including parts of the ...

'')

Reptiles

* ''Eimeria amphisbaeniarum'' - Mann's worm lizard ('' Amphisbaena manni'') * ''Eimeria witcheri'' - Mann's worm lizard (''A. manni'') * ''Eimeria yemenensae'' - rock agama ('' Agama yemenensis'')

Birds

* '' Eimeria acervulina'' -

chicken The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adu ...

(''Gallus gallus domesticus'')
* ''Eimeria adenoeides'' -

turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...

(''Meleagris gallopavo'')
* '' Eimeria brunetti'' - chicken (''G. g. domesticus'')
* ''Eimeria colchici'' -

common pheasant The common pheasant (''Phasianus colchicus'') is a bird in the pheasant family ( Phasianidae). The genus name comes from Latin ''phasianus'', "pheasant". The species name ''colchicus'' is Latin for "of Colchis" (modern day Georgia), a countr ...

(''Phasianus colchicus'') * ''Eimeria curvata'' -

ruddy ground dove The ruddy ground dove (''Columbina talpacoti'') is a small New World tropical dove. It is a resident breeder from Mexico south to Brazil, Peru and Paraguay, and northern Argentina, and on Trinidad and Tobago. Individual birds can sometimes be se ...

(''Columbina talpacoti''),

scaled dove The scaled dove (''Columbina squammata''), also known as scaly dove, Ridgway's dove, mottled dove, and South American zebra dove, is found in Brazil, Bolivia, Argentina, Colombia, French Guiana, Paraguay, Trinidad and Tobago, and Venezuela. It ...

(''Scardafella squammata'') * ''Eimeria dispersa'' - turkey (''M. gallopavo''), bobwhite quail ('' Colinus virginianus'') * ''Eimeria duodenalis'' - pheasant (''Phasianus colchicus'') * '' Eimeria fraterculae'' - Atlantic puffin (''

Fratercula arctica The Atlantic puffin ('), also known as the common puffin, is a species of seabird in the auk family. It is the only puffin native to the Atlantic Ocean; two related species, the tufted puffin and the horned puffin is found in the northeastern ...

'') * ''Eimeria gallopavonis'' - turkey (''M. gallopavo'')
* ''Eimeria innocua'' - turkey (''M. gallopavo'')
* ''Eimeria praecox'' - chicken (''G. g. domesticus'')
* '' Eimeria maxima'' - chicken (''G. g. domesticus'')
* '' Eimeria meleagridis'' - turkey (''M. gallopavo'') * ''Eimeria meleagrimitis'' - turkey (''M. gallopavo'') * ''Eimeria mitis'' - chicken (''G. g. domesticus'') * ''Eimeria muta'' -

rock ptarmigan The rock ptarmigan (''Lagopus muta'') is a medium-sized game bird in the grouse family. It is known simply as the ptarmigan in the UK. It is the official bird for the Canadian territory of Nunavut, where it is known as the ''aqiggiq'' (ᐊ� ...

(''Lagopus muta islandorum'') * '' Eimeria necatrix'' - chicken (''G. g. domesticus'') * ''Eimeria phasiani'' - pheasant (''P. colchicus'') * ''Eimeria procera'' - grey partridges ('' Perdix perdix'') * ''Eimeria purpureicephali '' - red-capped parrot (''

Purpureicephalus spurius The red-capped parrot (''Purpureicephalus spurius'') is a species of broad-tailed parrot native to southwestern Australia. It was described by Heinrich Kuhl in 1820, with no subspecies recognised. It has long been classified in its own genus ...

'') * ''Eimeria rjupa'' -

(''L. m. islandorum'') * '' Eimeria tenella'' - chicken (''G. g. domesticus'')

Mammals

* ''Eimeria ahsata'' - goat ('' Capra hircus''), sheep ('' Ovis aries'') * ''Eimeria alabamensis'' - cattle (''

Bos taurus Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult ma ...

'') * ''Eimeria alijevi'' - goat (''C. hircus'') * ''Eimeria aspheronica'' - goat (''C. hircus'') * ''Eimeria arloingi'' - goat (''C. hircus'') * ''Eimeria arundeli'' - common wombat (''

Vombatus ursinus The common wombat (''Vombatus ursinus''), also known as the coarse-haired wombat or bare-nosed wombat, is a marsupial, one of three extant species of wombats and the only one in the genus ''Vombatus''. The common wombat grows to an average of ...

'') * ''Eimeria bakuensis'' - sheep (''O. aries'') * '' Eimeria bovis'' - cattle (''B. taurus'') * ''Eimeria cameli'' - camels ('' Camelus bactrianus'','' Camelus dromedarius'') * ''Eimeria caprina'' - goat (''C. hircus'') * ''Eimeria caprovina'' - goat (''C. hircus'') * ''Eimeria christenseni'' - goat (''C. hircus'') * ''Eimeria clethrionomyis'' - red-backed vole ('' Clethrionomys gapperi'') * ''Eimeria coecicola'' - rabbit (''

Oryctolagus cuniculus The European rabbit (''Oryctolagus cuniculus'') or coney is a species of rabbit native to the Iberian Peninsula (including Spain, Portugal, and southwestern France), western France, and the northern Atlas Mountains in northwest Africa. It has ...

'') * ''Eimeria contorta'' - mouse (''

Mus musculus Mus or MUS may refer to: Abbreviations * MUS, the NATO country code for Mauritius * MUS, the IATA airport code for Minami Torishima Airport * MUS, abbreviation for the Centre for Modern Urban Studies on Campus The Hague, Leiden University, Net ...

'') * ''Eimeria couesii'' - rice rat ('' Oryzomys couesi'') * ''Eimeria crandallis'' - sheep (''O. aries'') * ''Eimeria dammahensis'' - scimitar-homed oryx (''

Oryx dammah The scimitar oryx (''Oryx dammah''), also known as the scimitar-horned oryx and the Sahara oryx, is a ''Oryx'' species that was once widespread across North Africa. In 2000, it was declared extinct in the wild on the IUCN Red List. A captive bre ...

'') * ''Eimeria dowleri'' - eastern red bat ('' Lasiurus borealis'') * ''Eimeria exigua'' - rabbit (''O. cuniculus'') * ''Eimeria falciformis'' - mouse (''M. musculus'') * ''Eimeria farasanii'' - mountain gazelle ('' Gazella gazelle farasani'') * ''Eimeria ferrisi'' - mouse (''M. musculus'') * ''Eimeria flavescens'' - rabbit (''O. cuniculus'') * ''Eimeria gallatii'' - red-backed vole (''C. gapperi'') * ''Eimeria granulosa'' - goat (''C. hircus'') * ''Eimeria hirci'' - goat (''C. hircus'') * ''Eimeria intestinalis'' - rabbit (''O. cuniculus'') * ''Eimeria irresidua'' - rabbit (''O. cuniculus'') * ''Eimeria intricata'' - goat (''C. hircus'') * ''Eimeria jolchijevi'' - goat (''C. hircus'') * ''Eimeria krijgsmanni'' - mouse (''M. musculus'') * ''Eimeria larimerensis'' - Uinta ground squirrel ('' Spermophilus armatus'') * ''Eimeria macusaniensis'' - llamas ('' Lama glama''), guanacos ('' Lama guanicoe''), alpacas ('' Vicugna pacos''), vicunas ('' Vicugna vicugna'') * ''Eimeria magna'' - rabbit (''O. cuniculus'') * ''Eimeria marconii'' - red-backed vole (''Clethrionomys gapperi'') * ''Eimeria media'' - rabbit (''O. cuniculus'') * ''Eimeria melanuri'' - garden dormouse ('' Eliomys quercinus'') * ''Eimeria myoxi'' - garden dormouse (''E. quercinus'') * ''Eimeria nagpurensis'' - rabbit (''O. cuniculus'') * ''Eimeria nieschulzi'' - brown rat (''R. norvegicus'') * ''Eimeria ninakohlyakimovae'' - goat (''C. hircus'') * ''Eimeria ovinoidalis'' - sheep (''O. aries'') * ''Eimeria pallida'' - goat (''C. hircus'') * ''Eimeria palustris'' - marsh rice rat ('' Oryzomys palustris'') * ''Eimeria papillata'' - mouse (''M. musculus'') * ''Eimeria perforans'' - rabbit (''O. cuniculus'') * ''Eimeria phocae'' - Sable Island harbour seals (''

Phoca vitulina The harbor (or harbour) seal (''Phoca vitulina''), also known as the common seal, is a true seal found along temperate and Arctic marine coastlines of the Northern Hemisphere. The most widely distributed species of pinniped (walruses, eared se ...

'') * ''Eimeria pileata'' - red-backed vole (''Clethrionomys gapperi'') * ''Eimeria pipistrellus'' - Kuhl's pipistrelle ('' Pipistrellus kuhlii'') * ''Eimeria piriformis'' - rabbit (''O. cuniculus'') * ''Eimeria prionotemni'' - Bennett's wallaby (''

Macropus rufogriseus The red-necked wallaby or Bennett's wallaby (''Notamacropus rufogriseus'') is a medium-sized macropod marsupial (wallaby), common in the more temperate and fertile parts of eastern Australia, including Tasmania. Red-necked wallabies have bee ...

'') * ''Eimeria procyonis'' - raccoon ('' Procyon lotor'') * ''Eimeria punctata'' - goat (''C. hircus'') * ''Eimeria roobroucki'' - rabbit (''O. cuniculus'') * ''Eimeria saudiensis'' - Arabian oryx (''

Oryx leucoryx The Arabian oryx (''Oryx leucoryx'') or white oryx is a medium-sized antelope with a distinct shoulder bump, long, straight horns, and a tufted tail. It is a bovid, and the smallest member of the genus ''Oryx'', native to desert and steppe areas o ...

'') * ''Eimeria sealanderi'' - eastern red bat (''Lasiurus borealis'') * ''Eimeria separata'' - mouse (''M. musculus''), rat (''

Rattus rattus The black rat (''Rattus rattus''), also known as the roof rat, ship rat, or house rat, is a common long-tailed rodent of the stereotypical rat genus ''Rattus'', in the subfamily Murinae. It likely originated in the Indian subcontinent, but is ...

'') * ''Eimeria stiedai'' - rabbit (''O. cuniculus'') * ''Eimeria ursini'' - southern hairy nosed wombat (''

Lasiorhinus latifrons The southern hairy-nosed wombat (''Lasiorhinus latifrons'') is one of three extant species of wombats. It is found in scattered areas of semiarid scrub and mallee from the eastern Nullarbor Plain to the New South Wales border area. It is the ...

'') * ''Eimeria vermiformis'' - mice (''M. musculus'') * ''Eimeria weybridgensis'' - sheep (''O. aries'') * ''Eimeria wobati'' - southern hairy-nosed wombat (''L. latifrons'') * '' Eimeria zuernii'' - cattle (''B. taurus'')

List of species

Eimeria vanasi ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered ...

'' * '' Eimeria vermiformis'' * '' Eimeria volgensis'' * '' Eimeria wobati'' * '' Eimeria wyomingensis'' * '' Eimeria yemenensae'' * '' Eimeria yukonensis'' * '' Eimeria zuernii''

References

External links

An overview of ''Eimeria'' and coccidiosisThe Life Cycle of Coccidia
{{Taxonbar, from=Q795375 Apicomplexa genera Conoidasida Poultry diseases Veterinary protozoology Parasites of birds Parasites of equines