Science topic

Apicomplexa - Science topic

A phylum of unicellular parasitic EUKARYOTES characterized by the presence of complex apical organelles generally consisting of a conoid that aids in penetrating host cells, rhoptries that possibly secrete a proteolytic enzyme, and subpellicular microtubules that may be related to motility.
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Publications related to Apicomplexa (4,638)
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Microbes are important in not only driving matter cycling, modulating water quality, but also serving as food for animals in intensive aquaculture systems, in which artificial substrates in combination of biofloc technology can be applied to strengthen microbial values and animal production. However, the influence of micro-habitats created by these...
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Background Hepatozoon spp. are tick-borne parasites causing subclinical to clinical disease in wild and domestic animals. Aim of this study was to determine Hepatozoon prevalence and species distribution among wild mammals and ticks in Europe. Methods Samples of wild mammals and ticks, originating from Austria, Bosnia and Herzegovina, Croatia, Bel...
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The phylum of Apicomplexa groups intracellular parasites that employ substrate-dependent gliding motility to invade host cells, egress from the infected cells and cross biological barriers. The glideosome associated connector (GAC) is a conserved protein essential to this process. GAC facilitates the association of actin filaments with surface tran...
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We are reporting the nearly complete genome of Theileria equi (Piroplasmida, Apicomplexa), which contains four nuclear chromosomes, a mitochondrial genome, and an apicoplast from the NVSL354 reference isolate. This report includes all six genetic molecules.
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Background Biting midges ( Culicoides spp.) are important vectors of diverse microbes such as viruses, protozoa, and nematodes that cause diseases in wild and domestic animals. However, little is known about the role of microbial communities in midge larval habitat utilization in the wild. In this study, we characterized microbial communities (bact...
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Ticks and tick-borne pathogens pose a significant threat to the health and welfare of humans and animals. Our knowledge about pathogens carried by ticks of Australian wildlife is limited. This study aimed to characterise ticks and tick-borne microorganisms from a range of wildlife species across six sites in Victoria, Australia. Following morpholog...
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Bovine eosinophilic myositis (BEM) is a specific inflammatory myopathy, often associated with Sarcocystis spp., with multifocal gray-green lesions leading to carcass condemnation with considerable economic losses. Here is described a peculiar case of BEM that occurred in an adult (16 month) cattle, born in France, bred, and slaughtered in Italy at...
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Oligotrophic, high-mountain saline lakes possess a diverse eukaryotic taxon and are among the most productive ecosystems in the world.However, observational limitations of micro eukaryotes owing to their small size, color and squishy anatomy have hindered their estimation. The present work involves the study of the composition and diversity of lowe...
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Apicomplexans and related lineages comprise many obligate symbionts of animals; some of which cause notorious diseases such as malaria. They evolved from photosynthetic ancestors and transitioned into a symbiotic lifestyle several times, giving rise to species with diverse non-photosynthetic plastids. Here we sought to reconstruct the evolution of...
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Apicomplexa are obligate intracellular parasites. While most species are restricted to specific hosts and cell types, Toxoplasma gondii can invade every nucleated cell derived from warm-blooded animals. This broad host range suggests that this parasite can recognize multiple host cell ligands or structures, leading to the activation of a central pr...
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Toxoplasma gondii is found as an intracellular protozoan parasite in the Apicomplexa phylum that can be transmitted to the fetus and causes miscarriage, infection, and asymptomatic neonatal disease. In the present study, we characterized the seroprevalence rate of anti-Toxoplasma gondii antibodies in a population of Iranian women with a recent a sp...
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Malaria is caused by infection with protozoan parasites of the Plasmodium genus, which is part of the phylum Apicomplexa. Most organisms in this phylum contain a relic plastid called the apicoplast. The apicoplast genome is replicated by a single DNA polymerase (apPOL), which is an attractive target for anti-malarial drugs. We screened small-molecu...
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In addition to their standard inorganic phosphate (Pi) nutritional function, Pi transporters have additional roles in several cells, including Pi sensing (the so-called transceptor) and a crucial role in Pi metabolism, where they control several phenotypes, such as virulence in pathogens and tumour aggressiveness in cancer cells. Thus, intracellula...
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This is the first record of gregarine infection in the worker midgut of the Neotropical termites Ruptitermes pitan and Ruptitermes reconditus. Gregarines have already been described in the gut and hemocoel in workers of other termite species, and although these protozoa are not able to kill these insects, they may affect their fitness. In the prese...
Preprint
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The protozoan pathogen Toxoplasma gondii relies on tight regulation of gene expression to invade and establish infection in its host. The divergent gene regulatory mechanisms of Toxoplasma and related apicomplexan pathogens rely heavily on regulators of chromatin structure and histone modifications. The important contribution of histone acetylation...
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The apicomplexan parasite Cyclospora cayetanensis causes seasonal foodborne outbreaks of the gastrointestinal illness cyclosporiasis. Prior to the coronavirus disease-2019 pandemic, annually reported cases were increasing in the USA, leading the US Centers for Disease Control and Prevention to develop a genotyping tool to complement cyclosporiasis...
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Knowledge of in situ diet of widespread rotifers is crucial for accurately understanding the trophic position, ecological function, and adaptability to environmental changes in aquatic ecosystems. However, it is challenging to achieve the in situ diet information due to the lack of efficient and comprehensive methods. Here, we investigated the diet...
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Klasifikasi adalah salah satu ilmu tertua dalam bidang biologi dimasa sebelum masehi (SM). Klasifikasi memiliki peran penting karena memudahkan manusia mempelajari makhluk hidup yang sangat banyak tetapi secara berkelompok. Posisi makhluk hidup didalam klasifikasi terus mengalami pergeseran seiring ditemukan teknologi yang lebih canggih dan detail...
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Bovine neosporosis is a disease of concern due to its global distribution and significant economic impact through massive losses in the dairy and meat industries. To date, there is no effective chemotherapeutic drug or vaccine to prevent neosporosis. Control of this disease is therefore dependent on efficient detection tests that may affect treatme...
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Background Toxoplasmosis as a zoonotic condition is developed by an intracellular protozoan parasite Toxoplasma gondii from the Apicomplexa phylum, which imposes economic losses on herds of animals and severe complications in immunocompromised people and pregnant women. This infectious disease can be transmitted to human beings from the contaminate...
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Neospora caninum is a member of Apicomplexa Phylum and the causative agent of neosporosis, a disease responsible for abortions in cattle. Apicomplexan parasites have a limited set of actin-binding proteins conducting the regulation of the dynamics of nonconventional actin. The parasite actin-based motility is implicated in the parasite invasion pro...
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One of the most fascinating things that a young person can experience in the complex realm of biology is the discovery of an animal living inside another animal. If this discovery takes place at an early enough stage in the development of a young person's view of the world-that is, before the rules and regulations of what society thinks are good an...
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Toxoplasma gondii glideosome-associated connector (GAC) is a giant armadillo-repeat protein, essential for parasite motility and conserved across Apicomplexa. It connects actin filaments to the plasma membrane via interactions with phosphatidic acid and membrane-spanning adhesins. It is unclear how GAC contributes to gliding motility and invasion a...
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Aproximadamente, un 50% de los gatos a nivel mundial han sido infectados con Toxoplasma gondii, un parasito apicomplexa de distribución mundial. En la mayoría de los casos, las infecciones son asintomáticas; sin embargo, pueden ocasionar la muerte sobre todo cuando hay complicaciones en el sistema respiratorio. El diagnóstico puede ser un desafío,...
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Intracellular Ca²⁺ mobilization induced by second messenger IP3 controls many cellular events in most of the eukaryotic groups. Despite the increasing evidence of IP3-induced Ca²⁺ in apicomplexan parasites like Plasmodium, responsible for malaria infection, no protein with potential function as an IP3-receptor has been identified. The use of bioinf...
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Members of the Apicomplexa phylum are unified by an apical complex tailored for motility and host cell invasion. It includes regulated secretory organelles and a conoid attached to the apical polar ring (APR) from which subpellicular microtubules emerge. In coccidia, the conoid is composed of a cone of spiraling tubulin fibers, two preconoidal ring...
Article
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Cyst-forming Apicomplexa (CFA) of the Sarcocystidae have a ubiquitous presence as pathogens of humans and farm animals transmitted through the food chain between hosts with few notable exceptions. The defining hallmark of this family of obligate intracellular protists consists of their ability to remain for very long periods as infectious tissue cy...
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Theileria parasites are responsible for devastating cattle diseases, causing major economic losses across Africa and Asia. Theileria spp. stand apart from other apicomplexa parasites by their ability to transform host leukocytes into immortalized, hyperproliferating, invasive cells that rapidly kill infected animals. The emergence of resistance to...
Conference Paper
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A toxoplasmose é uma infecção causada pelo protozoário apicomplexa Toxoplasma gondii. Esse protozoário tem distribuição cosmopolita e hábito de vida intracelular parasitário obrigatório, podendo parasitar animais homeotérmicos e aves, mas tendo como hospedeiro definitivo os felídeos, onde ocorre a reprodução sexuada do parasito e posteriormente a l...
Conference Paper
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Bovine coccidiosis is an acute or chronic disease which, in some countries, is at the top of the parasitic diseases in terms of its importance. It occurs mainly in the younger categories, and in older animals if it is provoked by conditions that lead to a decrease in immunity (stress, transport, some of the gastrointestinal diseases of other etiolo...
Article
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Virulence and persistence of the obligate intracellular parasite Toxoplasma gondii involve the secretion of effector proteins belonging to the family of dense granule proteins (GRAs) that act notably as modulators of the host defense mechanisms and participate in cyst wall formation. Subset of GRAs residing in the parasitophorous vacuole (PV) or ex...
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Toxoplasma gondii is a single-celled parasitic eukaryote that evolved to successfully propagate in any nucleated cell. As with any other eukaryote, its life cycle is regulated by signaling pathways controlled by kinases and phosphatases. T. gondii encodes an atypical bacterial-like phosphatase absent from mammalian genomes, named Shelph, after its...
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Little is known about the coccidian parasites of North American birds of the family Cardinalidae. A single isosporan, Isospora vanriperorum was previously described over 40 years ago from the northern cardinal, Cardinalis cardinalis from Hawaii. Since then, it was also reported in the green-winged saltator, Saltator similis from Brazil but the iden...
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The enteric protozoan parasites Cryptosporidium spp., Giardia duodenalis and Dientamoeba fragilis are-to various extents-contributors to the burden of gastrointestinal illness in high-income countries. Detection of these pathogens by microscopy examination is challenging because of the limited sensitivity and need for specific staining procedures....
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Phosphoinositides are important second messengers that regulate key cellular processes in eukaryotes. While it is known that a single phosphoinositol-3 kinase (PI3K) catalyses the formation of 3'-phosphorylated phosphoinositides (PIPs) in apicomplexan parasites like Plasmodium and Toxoplasma, how its activity and PI3P formation is regulated has rem...
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Background: Coccidiosis is a common infection among birds that is caused by Eimeria spp. (Protozoa, Phylum Apicomplexa). Eimeria is transmitted fecal-orally and replicated in the intestines. Coccidiosis causes economic losses and increases birds' susceptibility to other diseases. Methods: In this study, the broilers were experimentally infected by...
Article
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Sarcocystis is a zoonotic protozoan parasite of the phylum Apicomplexa, which infect several animals, including livestock species. Cattle are the intermediate host for several Sarcocystis species, including S. cruzi, S. hirsuta, S. hominis, S.heydorni, and S. rommeli. The current study was conducted to determine the prevalence of sarcocystosis infe...
Article
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Upon pathogen detection, macrophages normally stay sessile in tissues while dendritic cells (DCs) migrate to secondary lymphoid tissues. The obligate intracellular protozoan Toxoplasma gondii exploits the trafficking of mononuclear phagocytes for dissemination via unclear mechanisms. We report that, upon T. gondii infection, macrophages initiate th...
Preprint
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Mature gametocytes of Plasmodium ( P .) falciparum display a banana (falciform) shape conferred by a complex array of subpellicular microtubules (SPMT) associated to the inner membrane complex (IMC). Microtubule associated proteins (MAPs) define MT populations and modulate interaction to pellicular components. Several MAPs have been identified in T...
Article
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Apicomplexan parasites possess secretory organelles called rhoptries that undergo regulated exocytosis upon contact with the host. This process is essential for the parasitic lifestyle of these pathogens and relies on an exocytic machinery sharing structural features and molecular components with free-living ciliates. However, how the parasites coo...
Article
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Plasmodium, the causative agent of malaria, belongs to the phylum Apicomplexa. Most apicomplexans, including Plasmodium, contain an essential nonphotosynthetic plastid called the apicoplast that harbors its own genome that is replicated by a dedicated organellar replisome. This replisome employs a single DNA polymerase (apPol), which is expected to...
Article
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The Toxoplasma gondii tachyzoite is a singled-cell obligate intracellular parasite responsible for the acute phase of toxoplasmosis. This polarized cell exhibits an apical complex, a hallmark of the phylum Apicomplexa, essential for motility, invasion, and egress from the host cell. Located on the opposite end of the cell is the basal complex, an e...
Preprint
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Background: Data on the genus Sarcocystis in waterfowls are very limited. To the best of our knowledge, the species of Sarcocystis have previously never been recorded in ducks in China. Methods: Leg muscles were obtained from 26 domestic ducks Anas platyrhynchos in 2021 in China. Sarcocysts were observed using light microscopy (LM) and transmission...
Conference Paper
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Artificial lighting in show caves causes the growth of green photosynthetic biofilms, called lampenflora, on rock surfaces. This represents a worrisome ecological problem in caves as these biofilms cause aesthetical, physical and chemical damages on the rock substrates. Finding an efficient eco-friendly control method is now a priority to carry out...
Article
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Toxoplasma gondii is an obligate intracellular parasite of the phylum Apicomplexa. This life-threatening opportunistic pathogen establishes a chronic infection in human and animals that is resistant to immune attacks and chemotherapeutic intervention.
Conference Paper
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Haemoproteus parasites (Apicomplexa, Haemosporida) are highly diverse cosmopolitan avian blood parasites and are present worldwide. Their natural vectors remain non-identified for most of the Haemoproteus species and their lineages. Understanding which are the vectors of certain parasite species and lineage can help parasitologists to better unders...
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Coccidian protozoan species recorded from flycatchers are few, but they have been described with a certain frequency in recent years. In this context, the present study describes a new Isospora sp. from sepia-capped flycatchers Leptopogon amaurocephalus Tschudi, 1846 captured in the Itatiaia National Park and in a reforestation area which is about...
Article
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Birds are intermediate hosts and important reservoirs that play a significant role in Toxoplasma gondii (Apicomplexa, Sarcocystidae) epidemiology and infection transfer to humans by eating their raw or undercooked meat. The aim of this study is to diagnose the Toxoplasma gondii infection in three species of wild birds (Columba livia, Streptopelia s...
Article
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The mitochondrial respiratory chain is an essential pathway in most studied eukaryotes due to its roles in respiration and other pathways that depend on mitochondrial membrane potential. Apicomplexans are unicellular eukaryotes whose members have an impact on global health. The respiratory chain is a drug target for some members of this group, nota...
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Background Microbial symbioses in marine invertebrates are commonplace. However, characterizations of invertebrate microbiomes are vastly outnumbered by those of vertebrates. Protists and fungi run the gamut of symbiosis, yet eukaryotic microbiome sequencing is rarely undertaken, with much of the focus on bacteria. To explore the importance of micr...
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PurposeHabitat fragmentation is the main threat to primate survival in the world. Additionally, changes in the environments in which they live can also contribute to exposure to pathogens. To investigate some pathogens that free-living primates may be exposed to in Rio Grande do Sul State (RS; southern Brazil) and characterize the forest remnants i...
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Background Haemoproteus is a sister genus to malaria parasites (Plasmodium), which both belong to the order Haemosporida (Apicomplexa). Parasites of both genera are flourishing in birds, however, Haemoproteus species are noticeably less investigated. This is unfortunate because knowledge about close relatives of malaria pathogens is important for b...
Preprint
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Intracellular infectious agents, like the malaria parasite, Plasmodium falciparum , face the daunting challenge of how to invade a host cell. This problem may be even harder when the host cell in question is the enucleated red blood cell. Evolution has provided P. falciparum and related single-celled parasites within the phylum Apicomplexa with a c...
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Members of Apicomplexa are defined by apical cytoskeletal structures and secretory organelles, tailored for motility, invasion and egress. Gliding is powered by actomyosin-dependent rearward translocation of apically secreted transmembrane adhesins. In the human parasite Toxoplasma gondii, the conoid, composed of tubulin fibres and preconoidal ring...
Article
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Compared to other commonly examined passerine birds for coccidian (Apicomplexa) parasites, little is available on the coccidia of birds of the family Hirundinidae, including barn swallows (Hirundo rustica). Feces was collected in May 2022 from two nesting H. rustica in McCurtain County, Oklahoma, USA; the samples contained oöcysts representing a ne...
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In this study, the eukaryotic composition of gut contents in three tropical sea cucumber species, Stichopus monotuberculatus, S. chloronotus and Holothuria atra were surveyed and compared by metabarcoding analysis based on 18S rRNA gene V4 region. The sequences were assigned to 21.80 ± 1.07, 22.60 ± 0.68 and 22.40 ± 0.25 different phyla from the gu...
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Host cell invasion by intracellular, eukaryotic parasites within the phylum Apicomplexa, is a remarkable and active process involving the coordinated action of apical organelles and other structures. To date, capturing how these structures interact during invasion has been difficult to observe in detail. Here, we used cryogenic electron tomography...
Article
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Sarcocystis is a disease that affects both humans and animals alike(Dubey, Calero-Bernal, et al., 2015). the parasite needs to complete its life cycle two hosts(El-Dakhly et al., 2011). a definitive host represented by carnivores(Prakas & Butkauskas, 2012).and an intermediate host herbivores(Motamedi et al., 2020). belonging to the phylum Apicomple...
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Bats (order, Chiroptera) account for more than one-fifth of all mammalian species in the world and are infected by various intra-erythrocytic parasites of the family Plasmodiidae (Apicomplexa: Haemosporida), including Polychromophilus Dionisi, 1899. Recent advance in the molecular characterization of haemosporidian isolates has enabled their accura...
Article
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Toxoplasma gondii is a common zoonotic protozoan pathogen adapted to intracellular parasitism in many host cells of diverse organisms. Our previous work has identified 18 cyclic nucleotide phosphodiesterase (PDE) proteins encoded by the parasite genome, of which 11 are expressed during the lytic cycle of its acutely-infectious tachyzoite stage in h...
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Neospora caninum is an obligate intracellular protozoan parasite of the phylum Alveolata (subphylum Apicomplexa) which has not been studied extensively in a biochemical context. N. caninum is a primary cause of reproductive disorders causing mummification and abortion not only in cattle but also in other small ruminant species resulting in a substa...
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Rhoptry proteins (ROPs) of Apicomplexa are crucial secreted virulence factors and sources of vaccine candidates. To date, Eimeria tenella ROPs are not well studied. This study identified and characterized a novel E. tenella ROP (EtROP35), which showed the highest levels among 28 putative ROPs in previous sporozoite and merozoite transcriptomes. Seq...
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Avian haemosporidian parasites (Haemosporida, Apicomplexa) are globally distributed and infect birds of many orders. These pathogens have been much investigated in domestic and wild passeriform birds, in which they are relatively easy to access. In birds belonging to other orders, including owls (order Strigiformes), these parasites have been studi...
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Background and aim: In Indonesia, Madura cattle are native breeds that are expected to contribute to the improvement of regional meat self-sufficiency. Eimeria spp. are protozoans that are commonly found in ruminants. This study aimed to identify the occurrence and diversity of Eimeria spp. in Madura cattle. Materials and methods: In this study,...
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(Open Access: https://doi.org/10.1073/pnas.2208277119) Chloroplast protein import is mediated by translocons named TOC and TIC on the outer and inner envelope membranes, respectively. Translocon constituents are conserved among green lineages, including plants and green algae. However, it remains unclear whether Rhodophyta (red algae) share common...
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Introduction: Malaria is a life-threatening disease caused by deadliest parasites that are transmitted to people through the bites of infected female mosquitoes. In African region, most important human parasite among the sporozoa is Plasmodium, the causative agent of malaria. Epidemiology/Geographic Distribution: Most malaria cases and deaths occ...
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The phylum Apicomplexa includes thousands of species of unicellular parasites that cause a wide range of human and animal diseases such as malaria and toxoplasmosis. To infect, the parasite must first initiate active movement to disseminate through tissue and invade into a host cell, and then cease moving once inside. The parasite moves by gliding...