Eimeria
Coccidiosis
Oocysts
Poultry Diseases
Chickens
Protozoan Vaccines
Encyclopedias as Topic
Chiroptera
Eimeria pipistrellus n. sp. from Pipistrellus kuhlii (Chiroptera: Vespertilionidae) in Saudi Arabia. (1/182)
Fecal samples from 12 Pipistrellus kuhlii captured at Shagrah, Saudi Arabia, were examined for coccidia and three (25%) found to harbor a undescribed eimerian, herein described as Eimeria pipistrellus n. sp. Sporulated oocysts were subspherical, 24.8 x 23.2 (22-27 x 20-25) microns, with a bilayered and smooth wall. The micropyle was absent, but a large oocyst residuum and a single polar granule were present. Sporocysts were ovoid, 11.6 x 8.3 (10.5-13 x 7.5-9) microns, with a prominent Stieda body, but without a substiedal body; sporozoites lay head to tail in sporocysts and contained one large posterior refractile body. Eimeria pipistrellus n. sp. is the 3rd species of the genus Eimeria found from bats of the genus Pipistrellus. (+info)Eimeria curvata n. sp.(Apicomplexa: Eimeriidae) in Columbina talpacoti and Scardafella squammata (Aves: Columbidae) from Brazil. (2/182)
Eimeria curvata is a new coccidian described in the doves Columbina talpacoti and Scardafella squammata from western of the State of Sao Paulo, Brazil. The oocysts are ovoid to ellipsoid, 18.3 (17-19) microm x 15.5 (15-17) microm, with a shape index of 1.2 (1.1-1.3). The wall is colorless, smooth and double-layered. A polar granule is present, but there is no micropyle or oocyst residuum. The sporocysts are elongate, 12.3 (11.5-13) microm x 5.8 (5.5-6) microm with a curved anterior portion and a smooth, thin, single-layered wall. The Stieda body is protuberant and nipple-like; there is no substieda body. The sporozoites lie head-to-tail in the sporocyst and contain a large refractile body at the extremities. The sporocyst residuum contains small granules uniformly distributed in the middle of the sporocyst. The prevalence of E. curvata n. sp. was 17.4% and 12.8% in C. talpacoti and S. squammata, respectively. (+info)Genetic dissection of primary and secondary responses to a widespread natural pathogen of the gut, Eimeria vermiformis. (3/182)
Because most pathogens initially challenge the body at epithelial surfaces, it is important to dissect the mechanisms that underlie T-cell responses to infected epithelial cells in vivo. The coccidian parasites of the genus Eimeria are protozoan gut pathogens that elicit a potent, protective immune response in a wide range of host species. CD4+ alpha beta T cells and gamma interferon (IFN-gamma) are centrally implicated in the primary immunoprotective response. To define any additional requirements for the primary response and to develop a comparison between the primary and the secondary response, we have studied Eimeria infections of a broad range of genetically altered mice. We find that a full-strength primary response depends on beta(2)-microglobulin (class I major histocompatibility complex [MHC] and class II MHC and on IFN-gamma and interleukin-6 (IL-6) but not on TAP1, perforin, IL-4, Fas ligand, or inducible nitric oxide synthetase. Indeed, MHC class II-deficient and IFN-gamma-deficient mice are as susceptible to primary infection as mice deficient in all alpha beta T cells. Strikingly, the requirements for a highly effective alpha beta-T-cell-driven memory response are less stringent, requiring neither IFN-gamma nor IL-6 nor class I MHC. The class II MHC dependence was also reduced, with adoptively transferable immunity developing in MHC class II(-/-) mice. Besides the improved depiction of an immune response to a natural gut pathogen, the finding that effective memory can be elicited in the absence of primary effector responses appears to create latitude in the design of vaccine strategies. (+info)Description of Eimeria motelo sp. n. (Apicomplexa: Eimeriidae) from the yellow footed tortoise, Geochelone denticulata (Chelonia: Testudinidae), and replacement of Eimeria carinii Lainson, Costa & Shaw, 1990 by Eimeria lainsoni nom. nov. (4/182)
Eimeria motelo sp. n. is described from faeces of the yellow-footed tortoise, Geochelone denticulata (L.). Oocysts are irregularly ellipsoidal or cylindrical, with slightly expressed lobed protrusions and irregularities at the poles, possibly caused by wrinkling of the oocyst wall, 17 (15-19) x 9.4 (8.5-11) microm, shape index (length/width) being 1.81 (1.45-2). The oocyst wall is smooth, single-layered, 0.5 microm thick with no micropyle. There are no polar bodies. Sporocysts are ellipsoidal, 8.9 (7.5-10) x 4.4 (4-5) microm, shape index 2.03 (1.7-2.5). A sporocyst residuum is present, composed of many granules of irregular size. The sporozoites are elongate, lying lengthwise in the sporocysts. Comparison with other species of the genus Eimeria parasitising members of family Testudinidae indicates that the presently described coccidium represents a new species. The name of Eimeria carinii Lainson, Costa & Shaw, 1990 is found to be preoccupied by a homonym, Eimeria carinii Pinto 1928 given to a coccidium from Rattus norvegicus. Therefore, it is replaced by Eimeria lainsoni nom. nov. (+info)An alphabeta T-cell-independent immunoprotective response towards gut coccidia is supported by gammadelta cells. (5/182)
Although gammadelta cells are commonly hypothesized to provide a 'first line of defence', gammadelta-cell-deficient mice are generally only marginally more susceptible to pathogens. Because gammadelta cells are enriched within epithelia, it is important to resolve whether immunoprotective capacity towards epithelial-tropic pathogens is absent from the gammadelta-cell compartment, or whether such activity is present but simply redundant with that of alphabeta T cells. In this work, following infection of the intestinal epithelium of alphabeta T-cell-deficient mice with the coccidian parasite, Eimeria vermiformis, gammadelta cells were shown to support the rapid activation of other lymphoid cells and to confer a transferable antipathogen effect that could be eradicated by neutralization of interferon-gamma. However, unlike alphabeta T cells, these effects of gammadelta cells showed no evidence of functional immunological memory. These results are directly relevant to coccidiosis, an economically significant disease of livestock, and should have general relevance to infections involving alphabeta T-cell deficiencies, e.g. cryptosporidiosis in patients with acquired immune deficiency syndrome (AIDS). (+info)A new species of Eimeria (Apicomplexa, Eimeriidae) from the weedy sea dragon Phyllopteryx taeniolatus (Osteichthyes: Syngnathidae). (6/182)
A new species of intestinal coccidian is described from the weedy or common sea dragon Phyllopteryx taeniolatus housed at the New England Aquarium in Boston and at the Shedd Aquarium in Chicago, USA. Live oocysts of Eimeria phyllopterycis sp. n. are spherical, 30.9 (28.0-34.4) microm, with a thin, single-layered wall. Both a micropyle and oocyst residuum are absent and a large polar granule is sometimes present. Sporocysts are ellipsoidal and elongate, 24.3 x 10.4 (23.4-25.6 x 9.2-11.2) microm, with Stieda and substieda bodies; shape index (length/width) 2.33 (2.14-2.70). A sporocyst residuum is present, consisting of numerous granules of various sizes. Sporozoites each possess 3 refractile bodies. Preliminary evidence suggests that the coccidian may affect the health of sea dragons; however, it could not be determined whether this parasite caused significant morbidity or mortality. (+info)Effects of dietary protein types on immune responses and levels of infection with Eimeria vermiformis in mice. (7/182)
The present study reports the dietary effects of bovine alpha whey fraction, bovine casein and soy protein isolate on the immune responsiveness of C57BL/6J mice infected with Eimeria vermiformis. During the patent period, mice fed alpha whey fraction had significantly higher blood total white cell, CD4+ and CD8+ lymphocyte counts and higher Con A-stimulated IFN-gamma production by spleen cells than those fed other protein sources, but there was no significant difference in output of faecal oocysts. Casein-fed mice had significantly higher levels of Con A- stimulated IFN-gamma production and a lower output of faecal oocysts than soy-fed mice. The study demonstrated that dietary proteins have different impacts on immune responsiveness and level of parasitic infection in the gut; however, the mechanisms affecting level of infection are not clear. These effects appeared not to be solely related to nutritional properties of the diets. Further research into the underlying immune mechanisms and possible direct interactions between bioactive proteins and the parasite E. vermiformis should be fruitful. (+info)Reduction of the infectivity of Toxoplasma gondii and Eimeria stiedai sporozoites by treatment with bovine lactoferricin. (8/182)
Sporozoites of Toxoplasma gondii preincubated with lactoferricin showed decreased activity in penetration of mouse embryonal cells. Mice inoculated with 10(5) sporozoites preincubated with lactoferricin showed a higher survival rate than those inoculated with the same number of untreated sporozoites. Likewise, sporozoites of Eimeria stiedai preincubated with lactoferricin also showed decreased activity in penetration of rabbit hepatobiliary cells. Rabbits inoculated with 10(5) sporozoites preincubated with lactoferricin shed fewer oocysts than those inoculated with the same number of untreated sporozoites. These results indicate that lactoferricin is effective to reduce the infectivity of sporozoites of Toxoplasma gondii and Eimeria stiedai. (+info)'Eimeria' is a genus of protozoan parasites that belong to the phylum Apicomplexa. These microscopic organisms are known to cause a disease called coccidiosis in various animals, including birds, ruminants, and pigs. The life cycle of Eimeria involves both sexual and asexual reproduction, and it typically takes place within the intestinal cells of the host animal.
The infection can lead to a range of symptoms, such as diarrhea, weight loss, dehydration, and even death in severe cases, particularly in young animals. Eimeria species are highly host-specific, meaning that each species tends to infect only one type of animal. For example, Eimeria tenella primarily infects chickens, while Eimeria bovis is known to infect cattle.
Prevention and control measures for coccidiosis include good sanitation practices, such as cleaning and disinfecting animal living areas, as well as the use of anticoccidial drugs in feed or water to prevent infection. Additionally, vaccines are available for some Eimeria species to help protect animals from infection and reduce the severity of clinical signs.
'Eimeria tenella' is a species of intracellular parasitic protozoa belonging to the phylum Apicomplexa. It is one of the several Eimeria species that cause coccidiosis, a common and economically significant intestinal disease in poultry.
Eimeria tenella primarily infects the caeca (plural of cecum) of chickens, turkeys, and other birds. The life cycle of this parasite involves several stages, including sporulation, ingestion, excystation, merogony, gametogony, and oocyst shedding.
The oocysts are passed in the feces of infected birds and can survive in the environment for long periods. Once ingested by another bird, the oocysts release sporozoites, which invade the epithelial cells lining the caeca. Here, they undergo asexual reproduction (merogony), producing numerous merozoites that infect neighboring cells.
After several rounds of merogony, the parasite enters the sexual phase of its life cycle (gametogony). Male and female gametes fuse to form zygotes, which develop into oocysts and are shed in the feces, completing the life cycle.
Clinical signs of Eimeria tenella infection include diarrhea, bloody droppings, decreased appetite, weight loss, and decreased egg production. Severe infections can lead to death, particularly in young birds. Coccidiosis is typically treated with anticoccidial drugs, which are added to the feed or water of infected birds. Good management practices, such as proper sanitation and biosecurity, can help prevent the spread of Eimeria tenella and other coccidian species.
Coccidiosis is a parasitic infection caused by protozoa of the Eimeria genus, which typically affects the intestinal tract of animals, including humans. The infection occurs when a person or animal ingests oocysts (the infective stage of the parasite) through contaminated food, water, or direct contact with infected feces.
In humans, coccidiosis is most commonly found in children living in poor sanitary conditions and in individuals with weakened immune systems, such as those with HIV/AIDS or organ transplant recipients on immunosuppressive therapy. The infection can cause watery diarrhea, abdominal pain, nausea, vomiting, and fever. In severe cases, it may lead to dehydration, weight loss, and even death in individuals with compromised immune systems.
In animals, particularly in poultry, swine, and ruminants, coccidiosis can cause significant economic losses due to decreased growth rates, poor feed conversion, and increased mortality. Preventive measures include improving sanitation, reducing overcrowding, and administering anticoccidial drugs or vaccines.
An oocyst is a thick-walled, environmentally resistant spore-like structure produced by some protozoan parasites, such as Cryptosporidium and Cyclospora, during their life cycle. These oocysts can survive for long periods in the environment and can infect a host when ingested, leading to infection and disease. The term "oocyst" is specific to certain groups of protozoan parasites and should not be confused with other types of spores produced by fungi or bacteria.
Coccidiostats are a type of medication used to prevent and treat coccidiosis, which is an infection caused by protozoan parasites of the genus Coccidia. These medications work by inhibiting the growth and reproduction of the parasites in the gastrointestinal tract of animals, particularly poultry and livestock.
Coccidiostats are commonly added to animal feed to prevent infection and reduce the spread of coccidiosis within a flock or herd. They can also be used to treat active infections, often in combination with other medications. Common examples of coccidiostats include sulfaquinoxaline, monensin, and lasalocid.
It's important to note that the use of coccidiostats in food-producing animals is regulated by government agencies such as the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) to ensure their safe use and to minimize the risk of residues in animal products.
Poultry diseases refer to a wide range of infectious and non-infectious disorders that affect domesticated birds, particularly those raised for meat, egg, or feather production. These diseases can be caused by various factors including viruses, bacteria, fungi, parasites, genetic predisposition, environmental conditions, and management practices.
Infectious poultry diseases are often highly contagious and can lead to significant economic losses in the poultry industry due to decreased production, increased mortality, and reduced quality of products. Some examples of infectious poultry diseases include avian influenza, Newcastle disease, salmonellosis, colibacillosis, mycoplasmosis, aspergillosis, and coccidiosis.
Non-infectious poultry diseases can be caused by factors such as poor nutrition, environmental stressors, and management issues. Examples of non-infectious poultry diseases include ascites, fatty liver syndrome, sudden death syndrome, and various nutritional deficiencies.
Prevention and control of poultry diseases typically involve a combination of biosecurity measures, vaccination programs, proper nutrition, good management practices, and monitoring for early detection and intervention. Rapid and accurate diagnosis of poultry diseases is crucial to implementing effective treatment and prevention strategies, and can help minimize the impact of disease outbreaks on both individual flocks and the broader poultry industry.
"Chickens" is a common term used to refer to the domesticated bird, Gallus gallus domesticus, which is widely raised for its eggs and meat. However, in medical terms, "chickens" is not a standard term with a specific definition. If you have any specific medical concern or question related to chickens, such as food safety or allergies, please provide more details so I can give a more accurate answer.
There is no medical definition for "Protozoan Vaccines" as such because there are currently no licensed vaccines available for human protozoan diseases. Protozoa are single-celled microorganisms that can cause various diseases in humans, such as malaria, toxoplasmosis, and leishmaniasis.
Researchers have been working on developing vaccines against some of these diseases, but none have yet been approved for use in humans. Therefore, it is not possible to provide a medical definition for "Protozoan Vaccines" as a recognized category of vaccines.
An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.
Chiroptera is the scientific order that includes all bat species. Bats are the only mammals capable of sustained flight, and they are distributed worldwide with the exception of extremely cold environments. They vary greatly in size, from the bumblebee bat, which weighs less than a penny, to the giant golden-crowned flying fox, which has a wingspan of up to 6 feet.
Bats play a crucial role in many ecosystems as pollinators and seed dispersers for plants, and they also help control insect populations. Some bat species are nocturnal and use echolocation to navigate and find food, while others are diurnal and rely on their vision. Their diet mainly consists of insects, fruits, nectar, and pollen, although a few species feed on blood or small vertebrates.
Unfortunately, many bat populations face significant threats due to habitat loss, disease, and wind turbine collisions, leading to declining numbers and increased conservation efforts.
New World camelids are a family of mammals (Camelidae) that are native to South America. The family includes four species: the llama (Lama glama), the alpaca (Vicugna pacos), the guanaco (Lama guanicoe), and the vicuña (Vicugna vicugna). These animals are characterized by their long necks, long legs, and a pad on their chest instead of a true knee joint. They are known for their ability to survive in harsh environments with limited water and food resources.