Besnoitia bennetti | |
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Scientific classification | |
Domain: | Eukaryota |
Clade: | Diaphoretickes |
Clade: | SAR |
Clade: | Alveolata |
Phylum: | Apicomplexa |
Class: | Conoidasida |
Order: | Eucoccidiorida |
Family: | Sarcocystidae |
Genus: | Besnoitia |
Species: | B. bennetti |
Binomial name | |
Besnoitia bennetti (Bennett, 1927) Babudieri, 1932 | |
Besnoitia bennetti is a parasite that can cause besnoitiosis infections in donkeys. The range of this organism ranges from Africa to the United States. [1] [2] B. bennettii shares similar characteristics with Toxoplasma, Neospora, and Sarcocystis genera. [3] Lab work on B. bennetti is conducted at biosafety level 1. [4]
Besnoitia bennetti originated in Africa, causing besnoitiosis in donkeys and horses there. [2] Currently, the organism exists in Sudan, South Africa, France, the Pyrenees, Mexico, and the United States. [5] The first recorded infection of this species was documented in 1927 in Sudan. The species was believed to have spread from the Nuba Mountains. [5] [4] The first documented case in the United States occurred in 1957, when the species was found in the skin of burros. [5]
The instance of this species in a medical journal was in 1927, in an article written by S.C.J. Bennett. [6] In an expedition to Sudan, Bennett found four horses that had developed cysts consistent with what was eventually called besnoitiosis. Bennett at first mistakenly believed that the infection he found was caused by species of Sarcocystis or Globidium and that the organism infected cattle in addition to horses. In 1932, the species was placed into the Besnoitia genus by Babudieri. The first instance of an infection in South Africa appeared in a medical journal in 1955. B. bennetti was discovered in the United States in 1973 in an experimental herd of Mexican burros. [6]
In infected donkeys, B. bennetti formed cysts in the eyes, mouth, and testes. [1] [2] The mode of transmission among donkeys has not been determined. Treatments with ponazuril, trimethoprim-sulfamethoxazole, and nitroxinide have been unable to clear infection. [1]
While B. bennetti has only been found to infect donkeys, it has experimentally been shown not to infect mice, rats, gerbils, or cats. [6]
The donkey or ass is a domesticated equine. It derives from the African wild ass, Equus africanus, and may be classified either as a subspecies thereof, Equus africanus asinus, or as a separate species, Equus asinus. It was domesticated in Africa some 5000–7000 years ago, and has been used mainly as a working animal since that time.
Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii, an apicomplexan. Infections with toxoplasmosis are associated with a variety of neuropsychiatric and behavioral conditions. Occasionally, people may have a few weeks or months of mild, flu-like illness such as muscle aches and tender lymph nodes. In a small number of people, eye problems may develop. In those with a weak immune system, severe symptoms such as seizures and poor coordination may occur. If a person becomes infected during pregnancy, a condition known as congenital toxoplasmosis may affect the child.
Toxoplasma gondii is a parasitic protozoan that causes toxoplasmosis. Found worldwide, T. gondii is capable of infecting virtually all warm-blooded animals, but felids are the only known definitive hosts in which the parasite may undergo sexual reproduction.
Equus is a genus of mammals in the family Equidae, which includes horses, asses, and zebras. Within the Equidae, Equus is the only recognized extant genus, comprising seven living species. Like Equidae more broadly, Equus has numerous extinct species known only from fossils. The genus originated in North America and dispersed into the Old World and South America during the Early and Middle Pleistocene. Equines are odd-toed ungulates with slender legs, long heads, relatively long necks, manes, and long tails. All species are herbivorous, and mostly grazers, with simpler digestive systems than ruminants but able to subsist on lower-quality vegetation.
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 in severe cases, is the primary symptom. Most animals infected with coccidia are asymptomatic, but young or immunocompromised animals may suffer severe symptoms and death.
Besnoitia besnoiti is an apicomplexan protozoan parasite, closely related to Toxoplasma gondii and Neospora caninum,. It is part of a larger genus Besnoiti affecting multiple animal species, but Besnoita besnoiti, can affect livestock. and more specifically cattle as intermediate host, although some specific antibodies have been found in roe deer and red deer.
Balantidiasis is a protozoan infection caused by infection with Balantidium coli.
The African wild ass or African wild donkey is a wild member of the horse family, Equidae. This species is thought to be the ancestor of the domestic donkey, which is sometimes placed within the same species. They live in the deserts and other arid areas of the Horn of Africa, in Eritrea, Ethiopia and Somalia. It formerly had a wider range north and west into Sudan, Egypt, and Libya. It is Critically Endangered, with about 570 existing in the wild.
Sarcocystis is a genus of protozoan parasites, with many species infecting mammals, reptiles and birds. Its name is dervived from Greek sarx = flesh and kystis = bladder.
Neospora is a single celled parasite of livestock and companion animals. It was not discovered until 1984 in Norway, where it was found in dogs. Neosporosis, the disease that affects cattle and companion animals, has a worldwide distribution. Neosporosis causes abortions in cattle and paralysis in companion animals. It is highly transmissible and some herds can have up to a 90% prevalence. Up to 33% of pregnancies can result in aborted fetuses on one dairy farm. In many countries this organism is the main cause of abortion in cattle. Neosporosis is now considered as a major cause of abortion in cattle worldwide. Many reliable diagnostic tests are commercially available. Neospora caninum does not appear to be infectious to humans. In dogs, Neospora caninum can cause neurological signs, especially in congenitally infected puppies, where it can form cysts in the central nervous system.
Equine protozoal myeloencephalitis (EPM) is a disease that affects the central nervous system of horses. It is caused by a protozoal infection that is brought about by the apicomplexan parasites Sarcocystis neurona or Neospora hughesi. Most cases are caused by S. neurona. The lifecycle and transmission of N. hughesi is not well understood. The parasites create lesions in both the brain and spinal cord of the affected horses leading to neurological issues. Most horses infected with S. neurona do not exhibit neurological symptoms consistent with EPM.
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.
Asinus is a subgenus of Equus that encompasses several subspecies of the Equidae commonly known as wild asses, characterized by long ears, a lean, straight-backed build, lack of a true withers, a coarse mane and tail, and a reputation for considerable toughness and endurance.
Blastocystis is a genus of single-celled parasites belonging to the Stramenopiles that includes algae, diatoms, and water molds. There are several species, living in the gastrointestinal tracts of species as diverse as humans, farm animals, birds, rodents, reptiles, amphibians, fish, and cockroaches. Blastocystis has low host specificity, and many different species of Blastocystis can infect humans, and by current convention, any of these species would be identified as Blastocystis hominis.
Sarcocystis is a genus of parasitic Apicomplexan alveolates. Species in this genus infect reptiles, birds and mammals. The name is derived from Greek: sarkos = flesh and kystis = bladder.
Neospora hughesi is an obligate protozoan apicomplexan parasite that causes myelitis and equine protozoal myeloencephalitis (EPM) in horses, and has only been documented in North America. EPM is a neurological disease from lesions in the spinal cord, brain stem, or brain from parasites such as N. hughesi or Sarcocystis neurona. Signs that a horse may have EPM include ataxia, muscle atrophy, difficulty swallowing, and head tilt. There are antiprotozoal drugs, such as the 28-day course of ponazuril, to treat the disease, as well as anti-inflammatories to alleviate neurologic symptoms
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 typified by a cellular variety with a distinct morphology and biochemistry.
Besnoitiosis is a protozoan disease of the skin, subcutis, blood vessels, mucous membranes, and other tissues" of animals. It "is endemic in tropical and sub-tropical regions with high infection rate but low mortality"; however, it is rare in other regions.
Hammondia hammondi is a species of obligate heteroxenous parasitic alveolates of domestic cats. Intracellular cysts develop mainly in striated muscle. After the ingestion of cysts by cats, a multiplicative cycle precedes the development of gametocytes in the epithelium of the small intestine. Oocyst shedding persists for 10 to 28 days followed by immunity. Cysts in skeletal muscle measure between 100 and 340 μm in length and 40 and 95 μm in width. Some of the intermediate hosts develop low levels of antibody and some cross-immunity against Toxoplasma.
Sarcocystis neurona is primarily a neural parasite of horses and its management is of concern in veterinary medicine. The protozoan Sarcocystis neurona is a protozoan of single celled character and belongs to the family Sarcocystidae, in a group called coccidia. The protozoan, S. neurona, is a member of the genus Sarcocystis, and is most commonly associated with equine protozoal myeloencephalitis (EPM). S. neurona can be easily cultivated and genetically manipulated, hence its common use as a model to study numerous aspects of cell biology.