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1.
Parasitol Res ; 123(4): 182, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38622257

RESUMO

Avian haemosporidians are vector-borne parasites, infecting a great variety of birds. The order Passeriformes has the highest average infection probability; nevertheless, some common species of Passeriformes have been rather poorly studied. We investigated haemosporidians in one such species, the Eurasian jay Garrulus glandarius (Corvidae), from a forest population in Hesse, Central Germany. All individuals were infected with at least one haemosporidian genus (overall prevalence: 100%). The most common infection pattern was a mixed Haemoproteus and Leucocytozoon infection, whereas no Plasmodium infection was detected. Results on lineage diversity indicate a rather pronounced host-specificity of Haemoproteus and Leucocytozoon lineages infecting birds of the family Corvidae.


Assuntos
Doenças das Aves , Haemosporida , Parasitos , Passeriformes , Infecções Protozoárias em Animais , Aves Canoras , Humanos , Animais , Prevalência , DNA de Protozoário , Filogenia , Haemosporida/genética , Doenças das Aves/epidemiologia , Doenças das Aves/parasitologia , Infecções Protozoárias em Animais/epidemiologia , Infecções Protozoárias em Animais/parasitologia
2.
J Parasitol ; 110(2): 159-169, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38629270

RESUMO

Dicyemids (phylum Dicyemida) are the most common and most characteristic endosymbionts in the renal sacs of benthic cephalopod molluscs: octopuses and cuttlefishes. Typically, 2 or 3 dicyemid species are found in a single specimen of the host, and most dicyemids have high host specificity. Host-specific parasites are restricted to a limited range of host species by ecological barriers that impede dispersal and successful establishment; therefore, phylogenies of interacting groups are often congruent due to repeated co-speciation. Most frequently, however, host and parasite phylogenies are not congruent, which can be explained by processes such as host switching and other macro-evolutionary events. Here, the history of dicyemids and their host cephalopod associations were studied by comparing their phylogenies. Dicyemid species were collected from 8 decapodiform species and 12 octopodiform species in Japanese waters. Using whole mitochondrial cytochrome c oxidase subunit 1 (COI) sequences, a phylogeny of 37 dicyemid species, including 4 genera representing the family Dicyemidae, was reconstructed. Phylogenetic trees derived from analyses of COI genes consistently suggested that dicyemid species should be separated into 3 major clades and that the most common genera, Dicyema and Dicyemennea, are not monophyletic. Thus, morphological classification does not reflect the phylogenetic relationships of these 2 genera. Divergence (speciation) of dicyemid species seems to have occurred within a single host species. Possible host-switching events may have occurred between the Octopodiformes and Decapodiformes or within the Octopodiformes or the Decapodiformes. Therefore, the mechanism of dicyemid speciation may be a mixture of host switching and intra-host speciation. This is the first study in which the process of dicyemid diversification involving cephalopod hosts has been evaluated with a large number of dicyemid species and genera.


Assuntos
Octopodiformes , Parasitos , Animais , Filogenia , Invertebrados/anatomia & histologia , Invertebrados/genética , Decapodiformes/parasitologia
3.
Traffic ; 25(4): e12935, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38629580

RESUMO

The protozoan parasites Plasmodium falciparum, Leishmania spp. and Trypanosoma cruzi continue to exert a significant toll on the disease landscape of the human population in sub-Saharan Africa and Latin America. Control measures have helped reduce the burden of their respective diseases-malaria, leishmaniasis and Chagas disease-in endemic regions. However, the need for new drugs, innovative vaccination strategies and molecular markers of disease severity and outcomes has emerged because of developing antimicrobial drug resistance, comparatively inadequate or absent vaccines, and a lack of trustworthy markers of morbid outcomes. Extracellular vesicles (EVs) have been widely reported to play a role in the biology and pathogenicity of P. falciparum, Leishmania spp. and T. cruzi ever since they were discovered. EVs are secreted by a yet to be fully understood mechanism in protozoans into the extracellular milieu and carry a cargo of diverse molecules that reflect the originator cell's metabolic state. Although our understanding of the biogenesis and function of EVs continues to deepen, the question of how EVs in P. falciparum, Leishmania spp. and T. cruzi can serve as targets for a translational agenda into clinical and public health interventions is yet to be fully explored. Here, as a consortium of protozoan researchers, we outline a plan for future researchers and pose three questions to direct an EV's translational agenda in P. falciparum, Leishmania spp. and T. cruzi. We opine that in the long term, executing this blueprint will help bridge the current unmet needs of these medically important protozoan diseases in sub-Saharan Africa and Latin America.


Assuntos
Doença de Chagas , Vesículas Extracelulares , Leishmania , Parasitos , Trypanosoma cruzi , Animais , Humanos , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia
4.
Trop Anim Health Prod ; 56(4): 128, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38630347

RESUMO

Multi-host pathogens that infect various animal species and humans are considered of great importance for public and animal health. Leishmania spp. parasites are a characteristic example of such pathogens. Although leishmaniosis in humans is endemic for about 100 countries around the world it is classified as a neglected tropical disease. There are three main forms of leishmaniosis in humans: cutaneous (CL), visceral (VL) and mucocutaneous leishmaniosis (MCL). Each year, about 30,000 new cases of VL and more than 1 million new cases of CL are recorded. In Europe L. infantum is the dominant species with dogs being reservoir hosts. Apart from dogs, infection has been recorded in various animals, which suggests that other species could play a role in the maintenance of the parasite in nature. Herein we provide an in-depth review of the literature with respect to studies that deal with Leishmania infantum infections in domestic and wild animal species in Europe. Given the fact that domesticated and wild animals could contribute to the incidences of leishmaniosis in humans, the aim of this paper is to provide a comprehensive review which could potentially be used for the development of measures when it comes to the control of the Leishmania infantum parasite.


Assuntos
Leishmania infantum , Parasitos , Humanos , Animais , Cães , Animais Selvagens , Europa (Continente)/epidemiologia
5.
Cells ; 13(7)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38607032

RESUMO

Coevolution of hosts and their parasites has shaped heterogeneity of effector hemocyte types, providing immune defense reactions with variable effectiveness. In this work, we characterize hemocytes of Drosophila willistoni, a species that has evolved a cellular immune system with extensive variation and a high degree of plasticity. Monoclonal antibodies were raised and used in indirect immunofluorescence experiments to characterize hemocyte subpopulations, follow their functional features and differentiation. Pagocytosis and parasitization assays were used to determine the functional characteristics of hemocyte types. Samples were visualized using confocal and epifluorescence microscopy. We identified a new multinucleated giant hemocyte (MGH) type, which differentiates in the course of the cellular immune response to parasitoids. These cells differentiate in the circulation through nuclear division and cell fusion, and can also be derived from the central hematopoietic organ, the lymph gland. They have a binary function as they take up bacteria by phagocytosis and are involved in the encapsulation and elimination of the parasitoid. Here, we show that, in response to large foreign particles, such as parasitoids, MGHs differentiate, have a binary function and contribute to a highly effective cellular immune response, similar to the foreign body giant cells of vertebrates.


Assuntos
Drosophila , Parasitos , Animais , Diferenciação Celular , Fagocitose , Imunidade Celular
6.
Front Cell Infect Microbiol ; 14: 1304839, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38572319

RESUMO

Background: Chemotherapies for malaria and babesiosis frequently succumb to the emergence of pathogen-related drug-resistance. Host-targeted therapies are thought to be less susceptible to resistance but are seldom considered for treatment of these diseases. Methods: Our overall objective was to systematically assess small molecules for host cell-targeting activity to restrict proliferation of intracellular parasites. We carried out a literature survey to identify small molecules annotated for host factors implicated in Plasmodium falciparum infection. Alongside P. falciparum, we implemented in vitro parasite susceptibility assays also in the zoonotic parasite Plasmodium knowlesi and the veterinary parasite Babesia divergens. We additionally carried out assays to test directly for action on RBCs apart from the parasites. To distinguish specific host-targeting antiparasitic activity from erythrotoxicity, we measured phosphatidylserine exposure and hemolysis stimulated by small molecules in uninfected RBCs. Results: We identified diverse RBC target-annotated inhibitors with Plasmodium-specific, Babesia-specific, and broad-spectrum antiparasitic activity. The anticancer MEK-targeting drug trametinib is shown here to act with submicromolar activity to block proliferation of Plasmodium spp. in RBCs. Some inhibitors exhibit antimalarial activity with transient exposure to RBCs prior to infection with parasites, providing evidence for host-targeting activity distinct from direct inhibition of the parasite. Conclusions: We report here characterization of small molecules for antiproliferative and host cell-targeting activity for malaria and babesiosis parasites. This resource is relevant for assessment of physiological RBC-parasite interactions and may inform drug development and repurposing efforts.


Assuntos
Antimaláricos , Babesia , Babesiose , Malária Falciparum , Malária , Parasitos , Plasmodium , Animais , Humanos , Babesiose/tratamento farmacológico , Malária/parasitologia , Eritrócitos/parasitologia , Antimaláricos/farmacologia , Plasmodium falciparum
7.
Folia Parasitol (Praha) ; 712024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38567394

RESUMO

The present paper comprises a systematic survey of trematodes found in 13 species of freshwater fishes in Venezuela collected in 1992, 1996 and 2001. The following 15 trematode species were recorded: Adults: Genarchella venezuelaensis sp. n., Thometrema dissimilis sp. n., Megacoelium spinicavum Thatcher et Varella, 1981, Doradamphistoma bacuense Thatcher, 1999, Crassicutis cichlasomae Manter, 1936, Parspina carapo Ostrowski de Núñez, Arredonto et Gil de Pertierra, 2011, Phyllodistomoides hoplerythrini sp. n. Larvae (metacercariae): Clinostomatopsis sorbens (Braun, 1899), Clinostomum marginatum (Rudolphi, 1819), C. detruncatum Braun, 1899, Ithyoclinostomum dimorphum (Diesing, 1850), Odhneriotrema microcephala (Travassos, 1922), Tylodelphys sp., Posthodiplostomum sp., Sphincterodiplostomum sp. All these parasites are reported from Venezuela for the first time and many of these findings represent new host records. The new species G. venezuelaensis sp. n., T. dissimilis sp. n. and P. hoplerythrini sp. n. were collected from the accessory respiratory organ of Loricariichthys brunneus (Hancock) (Loricariidae), from the stomach of Hoplerythrinus unitaeniatus (Spix et Agassiz) (Erythrinidae) and from the intestine of H. unitaeniatus, respectively. All parasites are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Megacoelium spinispecum Thatcher et Varella, 1981 is considered a junior synonym of M. spinicavum Thatcher et Varella, 1981, and Crassicutis opisthoseminis Bravo-Hollis et Arroyo, 1962 as a junior synonym of C. cichlasomae Manter, 1936.


Assuntos
Peixes-Gato , Caraciformes , Doenças dos Peixes , Parasitos , Trematódeos , Infecções por Trematódeos , Animais , Venezuela/epidemiologia , Peixes/parasitologia , Água Doce , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/veterinária , Infecções por Trematódeos/parasitologia
8.
Syst Parasitol ; 101(3): 27, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38568382

RESUMO

The original description of Hatschekia exigua Pearse, 1951 neglected innumerous features of taxonomic value as well as morphometric data and illustrations. Posteriorly, other author tried to access the type material, but their poor state of preservation compromised a detailed redescription. Since then, this species is in need for new morphological data, mainly from fresh material. In the present work, three specimens of Holocentrus adscensionis from Mucuripe Bay, Fortaleza, State of Ceará, Northeastern Brazil, were parasitized by copepods on their gills. Parasites were fixed and preserved in 80% ethanol and cleared in 85% lactic acid for morphological observations using light microscopy. The females were identified as Hatschekia exigua by the cephalothorax representing about one-fourth of total body length, with lateral margins expanded into lateral lobes, first exopod with basal segment armed with one outer setae and terminal segment with three setae, first endopod with basal segment unarmed and terminal segment with five setae, leg 3 reduced to two setae and leg 4 reduced to single seta. Comparison with the type series revealed morphological differences in trunk and small appendages, which may be related to alterations in the specimens, caused by the mounting methodology and poor preservation. A detailed morphological analysis of the male revealed for the first time that they differ from their closest congeners by having five setae on the last endopodal segment of leg 1, by smooth intercoxal sclerites on legs 1 and 2 and by a proximolateral process on the third segment of antenna. Moreover, this work represents the first report of H. exigua in Brazil and the first hatschekiid copepod found off the coast of Ceará, highlighting that the diversity of Hatschekiidae in this oceanographic region still needs further investigation.


Assuntos
Copépodes , Parasitos , Animais , Feminino , Masculino , Brasil , Especificidade da Espécie , Peixes
9.
Parasit Vectors ; 17(1): 165, 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38556882

RESUMO

BACKGROUND: Trichomonas vaginalis is the most common nonviral sexually transmitted disease (STI) worldwide. Vaccination is generally considered to be one of the most effective methods of preventing infectious diseases. Using AP65, AP33 and α-actinin proteins, this research aims to develop a protein vaccine against Trichomonas vaginalis. METHODS: Based on the B-cell and T-cell epitope prediction servers, the most antigenic epitopes were selected, and with the necessary evaluations, epitope-rich domains of three proteins, AP65, AP33, and α-actinin, were selected and linked. Subsequently, the ability of the vaccine to interact with toll-like receptors 2 and 4 (TLR2 and TLR4) was assessed. The stability of the interactions was also studied by molecular dynamics for a duration of 100 nanoseconds. RESULTS: The designed protein consists of 780 amino acids with a molecular weight of 85247.31 daltons. The results of the interaction of the vaccine candidate with TLR2 and TLR4 of the immune system also showed that there are strong interactions between the vaccine candidate protein with TLR2 (-890.7 kcal mol-1) and TLR4 (-967.3 kcal mol-1). All parameters studied to evaluate the stability of the protein structure and the protein-TLR2 and protein-TLR4 complexes showed that the structure of the vaccine candidate protein is stable alone and in complex with the immune system receptors. Investigation of the ability of the designed protein to induce an immune response using the C-ImmSim web server also showed that the designed protein is capable of stimulating B- and T-cell lymphocytes to produce the necessary cytokines and antibodies against Trichomonas vaginalis. CONCLUSIONS: Overall, our vaccine may have potential protection against Trichomonas vaginalis. However, for experimental in vivo and in vitro studies, it may be a good vaccine candidate.


Assuntos
Parasitos , Trichomonas vaginalis , Vacinas , Animais , Trichomonas vaginalis/metabolismo , Actinina/metabolismo , Receptor 2 Toll-Like/metabolismo , Proteínas de Protozoários/metabolismo , 60444 , Receptor 4 Toll-Like/metabolismo , Vacinas/metabolismo , Epitopos de Linfócito T , Simulação de Acoplamento Molecular
10.
PeerJ ; 12: e17161, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38560466

RESUMO

The life history of a parasite describes its partitioning of assimilated resources into growth, reproduction, and transmission effort, and its precise timing of developmental events. The life cycle, in contrast, charts the sequence of morphological stages from feeding to the transmission forms. Phenotypic plasticity in life history traits can reveal how parasites confront variable environments within hosts. Within the protist phylum Apicomplexa major clades include the malaria parasites, coccidians, and most diverse, the gregarines (with likely millions of species). Studies on life history variation of gregarines are rare. Therefore, life history traits were examined for the gregarine Monocystis perplexa in its host, the invasive earthworm Amynthas agrestis at three sites in northern Vermont, United States of America. An important value of this system is the short life-span of the hosts, with only seven months from hatching to mass mortality; we were thus able to examine life history variation during the entire life cycle of both host and parasite. Earthworms were collected (N = 968 over 33 sample periods during one host season), then parasites of all life stages were counted, and sexual and transmission stages measured, for each earthworm. All traits varied substantially among individual earthworm hosts and across the sites. Across sites, timing of first appearance of infected earthworms, date when transmission stage (oocysts packed within gametocysts) appeared, date when number of both feeding (trophic) cells and gametocysts were at maximum, and date when 100% of earthworms were infected differed from 2-8 weeks, surprising variation for a short season available for parasite development. The maximal size of mating cells varied among hosts and across sites and this is reflected in the number of oocysts produced by the gametocyst. A negative trade-off was observed for the number of oocysts and their size. Several patterns were striking: (1) Prevalence reached 100% at all sites by mid season, only one to three weeks after parasites first appeared in the earthworms. (2) The number of parasites per host was large, reaching 300 × 103 cells in some hosts, and such high numbers were present even when parasites first appeared in the host. (3) At one site, few infected earthworms produced any oocysts. (4) The transmission rate to reach such high density of parasites in hosts needed to be very high for a microbe, from >0.33% to >34.3% across the three sites. Monocystis was one of the first protist parasites to have its life cycle described (early 19th century), but these results suggest the long-accepted life cycle of Monocystis could be incomplete, such that the parasites may be transmitted vertically (within the earthworm's eggs) as well as horizontally (leading to 100% prevalence) and merogony (asexual replication) could be present, not recognized for Monocystis, leading to high parasitemia even very early in the host's season.


Assuntos
Apicomplexa , Traços de História de Vida , Oligoquetos , Parasitos , Animais , Oligoquetos/parasitologia , Reprodução , Estágios do Ciclo de Vida , Oocistos
11.
BMC Vet Res ; 20(1): 126, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38561770

RESUMO

BACKGROUND: Ethno-veterinary practices could be used as a sustainable developmental tool by integrating traditional phytotherapy and husbandry. Phytotherapeutics are available and used worldwide. However, evidence of their antiparasitic efficacy is currently very limited. Parasitic diseases have a considerable effect on pig production, causing economic losses due to high morbidity and mortality. In this respect, especially smallholders and organic producers face severe challenges. Parasites, as disease causing agents, often outcompete other pathogens in such extensive production systems. A total of 720 faecal samples were collected in two farms from three age categories, i.e. weaners, fatteners, and sows. Flotation (Willis and McMaster method), modified Ziehl-Neelsen stained faecal smear, centrifugal sedimentation, modified Blagg technique, and faecal cultures were used to identify parasites and quantify the parasitic load. RESULTS: The examination confirmed the presence of infections with Eimeria spp., Cryptosporidium spp., Balantioides coli (syn. Balantidium coli), Ascaris suum, Oesophagostomum spp., Strongyloides ransomi, and Trichuris suis, distributed based on age category. A dose of 180 mg/kg bw/day of Allium sativum L. and 90 mg/kg bw/day of Artemisia absinthium L. powders, administered for 10 consecutive days, revealed a strong, taxonomy-based antiprotozoal and anthelmintic activity. CONCLUSIONS: The results highlighted the therapeutic potential of both A. sativum and A. absinthium against gastrointestinal parasites in pigs. Their therapeutic effectiveness may be attributed to the content in polyphenols, tocopherols, flavonoids, sterols, sesquiterpene lactones, and sulfoxide. Further research is required to establish the minimal effective dose of both plants against digestive parasites in pigs.


Assuntos
Anti-Infecciosos , Artemisia absinthium , Criptosporidiose , Cryptosporidium , Alho , Enteropatias Parasitárias , Parasitos , Doenças dos Suínos , Animais , Suínos , Feminino , Antiparasitários/farmacologia , Antiparasitários/uso terapêutico , Fazendas , Enteropatias Parasitárias/tratamento farmacológico , Enteropatias Parasitárias/veterinária , Enteropatias Parasitárias/parasitologia , Doenças dos Suínos/tratamento farmacológico , Doenças dos Suínos/parasitologia , Fezes/parasitologia , Prevalência
12.
Bull Math Biol ; 86(5): 54, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38598133

RESUMO

The development of mathematical models for studying newly emerging and re-emerging infectious diseases has gained momentum due to global events. The gyrodactylid-fish system, like many host-parasite systems, serves as a valuable resource for ecological, evolutionary, and epidemiological investigations owing to its ease of experimental manipulation and long-term monitoring. Although this system has an existing individual-based model, it falls short in capturing information about species-specific microhabitat preferences and other biological details for different Gyrodactylus strains across diverse fish populations. This current study introduces a new individual-based stochastic simulation model that uses a hybrid τ -leaping algorithm to incorporate this essential data, enhancing our understanding of the complexity of the gyrodactylid-fish system. We compare the infection dynamics of three gyrodactylid strains across three host populations. A modified sequential-type approximate Bayesian computation (ABC) method, based on sequential Monte Carlo and sequential importance sampling, is developed. Additionally, we establish two penalised local-linear regression methods (based on L1 and L2 regularisations) for ABC post-processing analysis to fit our model using existing empirical data. With the support of experimental data and the fitted mathematical model, we address open biological questions for the first time and propose directions for future studies on the gyrodactylid-fish system. The adaptability of the mathematical model extends beyond the gyrodactylid-fish system to other host-parasite systems. Furthermore, the modified ABC methodologies provide efficient calibration for other multi-parameter models characterised by a large set of correlated or independent summary statistics.


Assuntos
Parasitos , Animais , Teorema de Bayes , Conceitos Matemáticos , Modelos Biológicos , Simulação por Computador
13.
Front Cell Infect Microbiol ; 14: 1284701, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38585652

RESUMO

Bacterial obligate intracellular parasites (BOIPs) represent an exclusive group of bacterial pathogens that all depend on invasion of a eukaryotic host cell to reproduce. BOIPs are characterized by extensive adaptation to their respective replication niches, regardless of whether they replicate within the host cell cytoplasm or within specialized replication vacuoles. Genome reduction is also a hallmark of BOIPs that likely reflects streamlining of metabolic processes to reduce the need for de novo biosynthesis of energetically costly metabolic intermediates. Despite shared characteristics in lifestyle, BOIPs show considerable diversity in nutrient requirements, metabolic capabilities, and general physiology. In this review, we compare metabolic and physiological processes of prominent pathogenic BOIPs with special emphasis on carbon, energy, and amino acid metabolism. Recent advances are discussed in the context of historical views and opportunities for discovery.


Assuntos
Parasitos , Animais , Bactérias/genética , Vacúolos , Células Eucarióticas
14.
ACS Infect Dis ; 10(4): 1414-1428, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38556987

RESUMO

PDZ protein interacting specifically with Tc10 or PIST is a mammalian trans-Golgi resident protein that regulates subcellular sorting of plasma membrane receptors. PIST has recently emerged as a key player in regulating viral pathogenesis. Nevertheless, the involvement of PIST in parasitic infections remains unexplored. Leishmania parasites infiltrate their host macrophage cells through phagocytosis, where they subsequently multiply within the parasitophorous vacuole (PV). Host cell autophagy has been found to be important in regulating this parasite infection. Since PIST plays a pivotal role in triggering autophagy through the Beclin 1-PI3KC3 pathway, it becomes interesting to identify the status of PIST during Leishmania infection. We found that while macrophage cells are infected with Leishmania major (L. major), the expression of PIST protein remains unaltered; however, it traffics from the Golgi compartment to PV. Further, we identified that in L. major-infected macrophage cells, PIST associates with the autophagy regulatory protein Beclin 1 within the PVs; however, PIST does not interact with LC3. Reduction in PIST protein through siRNA silencing significantly increased parasite burden, whereas overexpression of PIST in macrophages restricted L. major infectivity. Together, our study reports that the macrophage PIST protein is essential in regulating L. major infectivity.


Assuntos
Leishmania major , Leishmaniose , Parasitos , Animais , Leishmania major/metabolismo , Proteína Beclina-1/metabolismo , Proteínas de Transporte/metabolismo , Macrófagos/metabolismo , Parasitos/metabolismo , Mamíferos/metabolismo
15.
Microb Biotechnol ; 17(4): e14455, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38635138

RESUMO

Toxoplasma gondii is a zoonotic parasite infecting humans and nearly all warm-blooded animals. Successful parasitism in diverse hosts at various developmental stages requires the parasites to fine tune their metabolism according to environmental cues and the parasite's needs. By manipulating the ß and γ subunits, we have previously shown that AMP-activated protein kinase (AMPK) has critical roles in regulating the metabolic and developmental programmes. However, the biological functions of the α catalytic subunit have not been established. T. gondii encodes a canonical AMPKα, as well as a KIN kinase whose kinase domain has high sequence similarities to those of classic AMPKα proteins. Here, we found that TgKIN is dispensable for tachyzoite growth, whereas TgAMPKα is essential. Depletion of TgAMPKα expression resulted in decreased ATP levels and reduced metabolic flux in glycolysis and the tricarboxylic acid cycle, confirming that TgAMPK is involved in metabolic regulation and energy homeostasis in the parasite. Sequential truncations at the C-terminus found an α-helix that is key for the function of TgAMPKα. The amino acid sequences of this α-helix are not conserved among various AMPKα proteins, likely because it is involved in interactions with TgAMPKß, which only have limited sequence similarities to AMPKß in other eukaryotes. The essential role of the less conserved C-terminus of TgAMPKα provides opportunities for parasite specific drug designs targeting TgAMPKα.


Assuntos
Parasitos , Toxoplasma , Animais , Humanos , Proteínas Quinases Ativadas por AMP , Sequência de Aminoácidos , Proliferação de Células
17.
Mol Biol Rep ; 51(1): 555, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38642192

RESUMO

The eradication of Plasmodium parasites, responsible for malaria, is a daunting global public health task. It requires a comprehensive approach that addresses symptomatic, asymptomatic, and submicroscopic cases. Overcoming this challenge relies on harnessing the power of molecular diagnostic tools, as traditional methods like microscopy and rapid diagnostic tests fall short in detecting low parasitaemia, contributing to the persistence of malaria transmission. By precisely identifying patients of all types and effectively characterizing malaria parasites, molecular tools may emerge as indispensable allies in the pursuit of malaria elimination. Furthermore, molecular tools can also provide valuable insights into parasite diversity, drug resistance patterns, and transmission dynamics, aiding in the implementation of targeted interventions and surveillance strategies. In this review, we explore the significance of molecular tools in the pursuit of malaria elimination, shedding light on their key contributions and potential impact on public health.


Assuntos
Malária , Parasitos , Plasmodium , Animais , Humanos , Malária/epidemiologia , Malária/prevenção & controle , Saúde Pública , Microscopia/métodos
18.
PLoS One ; 19(4): e0296146, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38626153

RESUMO

The fossil record of parasitism is poorly understood, due largely to the scarcity of strong fossil evidence of parasites. Understanding the preservation potential for fossil parasitic evidence is critical to contextualizing the fossil record of parasitism. Here, we present the first use of X-ray computed tomography (CT) scanning and finite elements analysis (FEA) to analyze the impact of a parasite-induced fossil trace on host preservation. Four fossil and three modern decapod crustacean specimens with branchial swellings attributed to an epicaridean isopod parasite were CT scanned and examined with FEA to assess differences in the magnitude and distribution of stress between normal and swollen branchial chambers. The results of the FEA show highly localized stress peaks in reaction to point forces, with higher peak stress on the swollen branchial chamber for nearly all specimens and different forces applied, suggesting a possible shape-related decrease in the preservation potential of these parasitic swellings. Broader application of these methods as well as advances in the application of 3D data analysis in paleontology are critical to understanding the fossil record of parasitism and other poorly represented fossil groups.


Assuntos
Decápodes , Isópodes , Parasitos , Animais , Paleontologia , Fósseis , Isópodes/parasitologia
19.
Proc Biol Sci ; 291(2021): 20240103, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38628126

RESUMO

Within-host interactions among coinfecting parasites can have major consequences for individual infection risk and disease severity. However, the impact of these within-host interactions on between-host parasite transmission, and the spatial scales over which they occur, remain unknown. We developed and apply a novel spatially explicit analysis to parasite infection data from a wild wood mouse (Apodemus sylvaticus) population. We previously demonstrated a strong within-host negative interaction between two wood mouse gastrointestinal parasites, the nematode Heligmosomoides polygyrus and the coccidian Eimeria hungaryensis, using drug-treatment experiments. Here, we show this negative within-host interaction can significantly alter the between-host transmission dynamics of E. hungaryensis, but only within spatially restricted neighbourhoods around each host. However, for the closely related species E. apionodes, which experiments show does not interact strongly with H. polygyrus, we did not find any effect on transmission over any spatial scale. Our results demonstrate that the effects of within-host coinfection interactions can ripple out beyond each host to alter the transmission dynamics of the parasites, but only over local scales that likely reflect the spatial dimension of transmission. Hence there may be knock-on consequences of drug treatments impacting the transmission of non-target parasites, altering infection risks even for non-treated individuals in the wider neighbourhood.


Assuntos
Coinfecção , Eimeria , Enteropatias Parasitárias , Parasitos , Animais , Camundongos , Interações Hospedeiro-Parasita , Murinae/parasitologia , Suscetibilidade a Doenças
20.
J Parasitol ; 110(2): 179-185, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38631697

RESUMO

Allegheny woodrats (Neotoma magister) are karst-specializing rodents that are rare or in conservation need in many states within their current range. Parasitism and habitat fragmentation have been suggested as primary reasons for declining populations. The presence, prevalence, and impact of ectoparasites, including fleas, ticks, and bots, is not fully understood rangewide. We collected Allegheny woodrat ectoparasites across 8 states in their range, identifying parasites via morphological and genetic means. Across contributions from 8 states, we discovered 2 woodrat-specific fleas parasitizing Allegheny woodrats: Orchopeas pennsylvanicus (all contributing states, n = 228) and Epitedia cavernicola (Indiana only, n = 9). The former was a new state record in New Jersey and Ohio. Woodrat specialists Ixodes woodi were morphologically identified as the dominant tick species (n = 38), and our contributions to genetic databases may ease confusion in future efforts. Three generalist species of ticks representing 8 individuals were identified as Dermacentor variabilis, Amblyomma americanum, and Ixodes scapularis. Only 2 bot fly species were recognized in Allegheny woodrats: 1 squirrel bot (Cuterebra emasculator) and 10 individuals of Cuterebra sp. not genetically conspecific to any known eastern U.S. rodent bot. The host specificity for fleas is not surprising, given that previous small-scale surveys and ticks primarily appear to be a mix of genus-specific (Ixodes woodi) and generalist species. There remains uncertainty with bots via morphological and genetic analyses. Our survey presents a wide-ranging baseline survey for Allegheny woodrats across their range, emphasizing the diversity (or specificity) of parasite groups for this species. An understanding of Allegheny woodrats and the health impact of ectoparasites is imperative because they face myriad challenges rangewide, especially considering the bot-driven demise of 1 woodrat in our study. Ectoparasites can have a marked impact on already-declining woodrat populations across their range and should not be overlooked in future surveys.


Assuntos
Ixodes , Parasitos , Sifonápteros , Animais , Indiana , Sigmodontinae/parasitologia
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