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 woman 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.
The Agricultural Research Service (ARS) is the principal in-house research agency of the United States Department of Agriculture (USDA). ARS is one of four agencies in USDA's Research, Education and Economics mission area. ARS is charged with extending the nation's scientific knowledge and solving agricultural problems through its four national program areas: nutrition, food safety and quality; animal production and protection; natural resources and sustainable agricultural systems; and crop production and protection. ARS research focuses on solving problems affecting Americans every day. The ARS Headquarters is located in the Jamie L. Whitten Building on Independence Avenue in Washington, D.C., and the headquarters staff is located at the George Washington Carver Center (GWCC) in Beltsville, Maryland. For 2018, its budget was $1.2 billion.
Parasitology is the study of parasites, their hosts, and the relationship between them. As a biological discipline, the scope of parasitology is not determined by the organism or environment in question but by their way of life. This means it forms a synthesis of other disciplines, and draws on techniques from fields such as cell biology, bioinformatics, biochemistry, molecular biology, immunology, genetics, evolution and ecology.
Veterinary parasitology is a branch of veterinary medicine that deals with the study of morphology, life-cycle, pathogenesis, diagnosis, treatment, and control of eukaryotic invertebrates of the kingdom Animalia and the taxon Protozoa that depend upon other invertebrates and higher vertebrates for their propagation, nutrition, and metabolism without necessarily causing the death of their hosts. Modern parasitology focuses on responses of animal hosts to parasitic invasion. Parasites of domestic animals,, as well as wildlife animals are considered. Data obtained from parasitological research in animals helps in veterinary practice and improves animal breeding. The major goal of veterinary parasitology is to protect animals and improve their health, but because a number of animal parasites are transmitted to humans, veterinary parasitology is also important for public health.
Coccidia (Coccidiasina) are a subclass of microscopic, spore-forming, single-celled obligate intracellular parasites belonging to the apicomplexan class Conoidasida. As obligate intracellular parasites, they must live and reproduce within an animal cell. Coccidian parasites infect the intestinal tracts of animals, and are the largest group of apicomplexan protozoa.
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.
Neospora caninum is a coccidian parasite that was identified as a species in 1988. Prior to this, it was misclassified as Toxoplasma gondii due to structural similarities. The genome sequence of Neospora caninum has been determined by the Wellcome Trust Sanger Institute and the University of Liverpool. Neospora caninum is an important cause of spontaneous abortion in infected livestock.
Micronemes are secretory organelles, possessed by parasitic apicomplexans. Micronemes are located on the apical third of the protozoan body. They are surrounded by a typical unit membrane. On electron microscopy they have an electron-dense matrix due to the high protein content. They are specialized secretory organelles important for host-cell invasion and gliding motility.
Besnoitia bennetti is a parasite that can cause besnoitiosis infections in donkeys. The range of this organism ranges from Africa to the United States. B. bennettii shares similar characteristics with Toxoplasma, Neospora, and Sarcocystis genera. Lab work onB. bennetti is conducted at biosafety level 1.
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.
The Sarcocystidae are a family of Apicomplexa associated with a variety of diseases in humans and other animals.
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.
Risk assessment for organic swine health is the process of evaluating the likelihood and potential impact of various factors that may affect the health and well-being of organic swine. Risks associated with organic swine farming may differ to those associated with non-organic swine farming, and is of increasing relevance due to growth in the sector. While organic swine farming makes up a small share of U.S. swine farming overall, numbers have increased significantly in recent years. Additionally, non-certified organic swine herds are not accounted in official statistics. Consumer demand, stemming from the larger organic agriculture movement has helped spur growth in this industry.
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). The protozoan, S. neurona, can be easily cultivated and genetically manipulated, hence its common use as a model to study numerous aspects of cell biology.
Joanne P. Webster is a British epidemiologist who is the Royal Veterinary College Chair in Parasitic Diseases, Director of the Centre for Emerging, Endemic and Exotic Diseases and Professor of Infectious Diseases at Imperial College London. She is a Fellow of the Royal Society of Biology and Fellow of the Academy of Medical Sciences.
