Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.616
Filtrar
1.
Braz. j. biol ; 84: e254251, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1350307

RESUMO

Abstract Blood and fecal samples of chukar partridge (Alectoris chukar), albino pheasant (Phasianus colchicus), silver pheasant (Lophura nycthemera), rose-ringed parakeet (Psittacula krameri) and turkeys (Meleagris gallopavo) were analyzed to check parasitic prevalence. To record parasites these five avian species were placed kept in separate cages at Avian Conservation and Research Center, Department of Wildlife an Ecology, University of Veterinary and Animal Sciences, Lahore, Pakistan. 100 fecal and 100 blood samples for each bird species were inspected to analyze internal parasites. During present study, 17 species of endoparasites 14 from fecal samples and three from blood were examined. Two species of ectoparasites i.e. mite Dermanyssus gallinae 42% and fowl ticks Args persicus 41%were studied. Blood parasites included Plasmodium juxtanucleare 50%, Leucoctoyzoon simond having parasitic prevalence 40%, and Aegyptinella pullorum having parasitic prevalence of 40%. Parasitic species recorded from fecal samples included 6 species of nematodes viz. Allodpa suctoria 2%. Syngamus trachea with parasitic prevalence of 60%, Capillaria annulata 37.5%, Ascardia galli 24%, Capillaria anatis 40% and Heterakis gallinarum 28.3%. Similarly, two species of trematodes viz. Prosthogonimus ovatus having parasitic prevalence of 50% and Prosthogonimus macrorchis 21% were also documented from fecal avian samples . Single cestode species Raillietina echinobothrida having parasitic prevalence of 72% and 3 protozoan species i.e. Eimeria maxima having parasitic prevalence of 21%, Giardia lamblia 41% and Histomonas meleagridis 18% were documented during corpological analysis. In our recommendation, proper sanitation, medication and vaccination of bird's enclousres are suggested to avoid parasites.


RESUMO Amostras de sangue e fezes de perdiz chukar (Alectoris chukar), faisão-albino (Phasianus colchicus), faisão-prateado (Lophura nycthemera), periquito-de-rosa (Psittacula krameri) e perus (Meleagris gallopavo) foram analisadas para verificar a prevalência de parasitas. Para registrar os parasitas, essas cinco espécies de aves foram colocadas em gaiolas separadas no Centro de Conservação e Pesquisa de Aves, Departamento de Vida Selvagem e Ecologia, Universidade de Veterinária e Ciências Animais, Lahore, Paquistão. Cem amostras fecais e 100 amostras de sangue para cada espécie de ave foram inspecionadas para analisar os parasitas internos. Durante o presente estudo, foram examinadas 17 espécies de endoparasitas, 14 de amostras fecais e 3 de sangue. Foram estudadas duas espécies de ectoparasitas, ou seja, o ácaro Dermanyssus gallinae 42% e o carrapato aviário Args persicus 41%. Os parasitas sanguíneos incluíram Plasmodium juxtanucleare 50%, Leucoctoyzoon simond com prevalência parasitária de 40% e Aegyptinella pullorum com prevalência parasitária de 40%. As espécies parasitas registradas em amostras fecais incluíram 6 espécies de nematoides viz. Allodpa suctoria 2%, Syngamus traqueia com prevalência parasitária de 60%, Capillaria annulata 37,5%, Ascardia galli 24%, Capillaria anatis 40% e Heterakis gallinarum 28,3%. Da mesma forma, duas espécies de trematódeos viz. Prosthogonimus ovatus com prevalência parasitária de 50% e Prosthogonimus macrorchis 21% também foram documentados em amostras fecais de aves. Espécies de cestoide único Raillietina echinobothrida com prevalência parasitária de 72% e 3 espécies de protozoários, isto é, Eimeria maxima com prevalência parasitária de 21%, Giardia lamblia 41% e Histomonas meleagridis 18% foram documentadas durante a análise corpológica. Em nossa recomendação, o saneamento adequado, medicação e vacinação de invólucros de pássaros são sugeridos para evitar parasitas.


Assuntos
Animais , Parasitos , Doenças das Aves/epidemiologia , Galliformes , Prevalência , Animais Selvagens
2.
Braz. j. biol ; 83: e248978, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1339406

RESUMO

Abstract The present research was planned to assess the occurrence of intestinal parasites in small ruminants of Upper Dir of Khyber Pakhtunkhwa Province of Pakistan. For this purpose, the faecal material was collected randomly with gloved fingers directly from the rectum region of sheep and goats and the faecal materials were then put in hygienic plastic bottles with 10% formalin. The overall 315 (n=184 sheep and n= 131 goats) faecal samples were collected out of 315 samples, 281 were found positive for different parasites. Patterns-wise prevalence of GI parasites of the study area was found. Overall Single parasitism 89.20% (281/315) with 94.0% (173/184) in sheep and 82.43% (108/131) in goats. Double parasitic infection in small ruminant recorded in which Fasciola+ Haemonchus. contortus in sheep were found their prevalence was 25.54% (47/184). While in goats, the double parasitic infection in which Haemonchus contortus+Trichuris spp were found and their prevalence were 23.43% (30/131). The species found in the sample of sheep were includes, i.e., Strongyloides papillosus (41.30%), Heamonchus controtus (21.73%), Trichuris ovis (17.39%), and Fasciola hepatica (13.58%), the corresponding value for goat were Strongyloides spp 33.33% (36/108), Haemonchus spp 28.70%, (27/108), Trichuris spp 25.20% (27/184) and Fasciola spp 10.68% (14/184). The sheep of the study area are more infected as compared to goats. This study suggested that gastrointestinal parasites are major health problems of small ruminants in the study area. Therefore, a comprehensive study on species of gastrointestinal parasites circulating in the area, control options, cost-effective strategies and awareness about gastrointestinal parasites among the farmers in the study area should be instituted.


Resumo A presente pesquisa foi planejada para avaliar a ocorrência de parasitas intestinais em pequenos ruminantes do distrito Upper Dir, da província de Khyber Pakhtunkhwa, no Paquistão. Para tanto, o material fecal foi coletado aleatoriamente com dedos enluvados diretamente da região do reto de ovelhas e cabras, e os materiais fecais foram colocados em garrafas plásticas higiênicas com formol a 10%. No total, 315 (n = 184 ovelhas e n = 131 cabras) amostras fecais foram coletadas; destas, 281 foram consideradas positivas para diferentes parasitas. A prevalência de padrões de parasitas GI da área de estudo foi encontrada. Parasitismo global único 89,20% (281/315) com 94,0% (173/184) em ovinos e 82,43% (108/131) em cabras. Infecção parasitária dupla em pequenos ruminantes registrada em Fasciola + Haemonchus contortus em ovinos, sua prevalência foi de 25,54% (47/184). Já em caprinos, a dupla infecção parasitária em que Haemonchus contortus + Trichuris spp foram encontrados e sua prevalência foi de 23,43% (30/131). As espécies encontradas na amostra de ovinos foram: Strongyloides papillosus (41,30%), Heamonchus controtus (21,73%), Trichuris ovis (17,39%) e Fasciola hepatica (13,58%), o valor correspondente para cabra foi Strongyloides spp. 33,33% (36/108), Haemonchus spp. 28,70%, (27/108), Trichuris sp 25,20% (27/184) e Fasciola spp. 10,68% (14/184). As ovelhas da área de estudo estão mais infectadas do que as cabras. Este estudo sugeriu que os parasitas gastrointestinais são os principais problemas de saúde dos pequenos ruminantes na área de estudo. Portanto, um estudo abrangente sobre as espécies de parasitas gastrointestinais que circulam na área, opções de controle, estratégias de baixo custo e conscientização sobre parasitas gastrointestinais entre os agricultores na área de estudo deve ser instituído.


Assuntos
Animais , Parasitos , Doenças dos Ovinos/epidemiologia , Doenças das Cabras/epidemiologia , Paquistão/epidemiologia , Ruminantes , Cabras , Ovinos , Prevalência , Fezes
3.
Braz. j. biol ; 83: e246887, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285630

RESUMO

Abstract The current study was carried out to estimate the prevalence and diversity of ectoparasites in rock pigeons in different regions of Punjab, Pakistan. A total of 120 birds were captured from March 2017 to February 2019. The ectoparasites were collected by standard procedures and preserved in 70% ethanol containing one drop of glycerin. Data related to age, health status, sex, type of area, sampling location and season were collected using a standardized form. Ectoparasites were identified based on morphological characteristics by using identification keys. Ninety-six (80%) birds were infested with ectoparasites. A total of seven families and thirteen species of different ectoparasites were observed. Mainly, seven species of lice, two species of flies, one species of tick and three species of mites were recovered from infested birds. The female pigeons were more often infested (89.02%) than male pigeons (60.52%). The prevalence was found higher during summer (100%) as compared to other seasons. The infestation rate was higher in Industrial area (97.50%) as compared to other regions. The highest prevalence of ectoparasites (100%) was recorded from Sargodha district. There was significant (P < 0.05) variation among number of ectoparasites on wing, chest, tail and neck within age groups, seasons and ecological zones. The occurrence of parasites in relation to area, age, health status, sex and season were significant. The infestation rate of parasites in rock pigeon is high in different districts of Punjab. It is recommended that these wild birds infested with multiple species of ectoparasites could be the potential source of infestations in domesticated birds if they come in contact with them. The contact of domesticated birds should be prevented from wild birds to minimize the chance of cross species transmission of ectoparasites.


Resumo O presente estudo foi realizado para estimar a prevalência e diversidade de ectoparasitas em pombos-das-rochas em diferentes regiões de Punjab, Paquistão. Um total de 120 aves foram capturadas de março de 2017 a fevereiro de 2019. Os ectoparasitas foram coletados por procedimentos padrão e preservados em etanol 70% contendo uma gota de glicerina. Os dados relativos à idade, estado de saúde, sexo, tipo de área, local de amostragem e época do ano foram coletados em formulário padronizado. Os ectoparasitas foram identificados com base nas características morfológicas por meio de chaves de identificação. Noventa e seis (80%) aves estavam infestadas com ectoparasitas. Um total de sete famílias e treze espécies de diferentes ectoparasitas foram observados. Principalmente, sete espécies de piolhos, duas espécies de moscas, uma espécie de carrapato e três espécies de ácaros foram recuperadas de aves infestadas. Os pombos fêmeas foram infestados mais frequentemente (89,02%) do que os pombos machos (60,52%). A prevalência encontrada foi maior no verão (100%) em comparação com as outras estações. A taxa de infestação foi maior na área Industrial (97,50%) em relação às demais regiões. A maior prevalência de ectoparasitas (100%) foi registrada no distrito de Sargodha. Houve variação significativa (P <0,05) entre o número de ectoparasitas na asa, tórax, cauda e pescoço dentro das faixas etárias, estações do ano e zonas ecológicas. A ocorrência de parasitas em relação à área, idade, estado de saúde, sexo e estação do ano foi significativa. A taxa de infestação de parasitas em pombo-correio é alta em diferentes distritos de Punjab. Recomenda-se que essas aves selvagens infestadas com várias espécies de ectoparasitas possam ser a fonte potencial de infestações em aves domesticadas se entrarem em contato com elas. O contato de aves domesticadas deve ser evitado com aves selvagens para minimizar a chance de transmissão cruzada de ectoparasitas.


Assuntos
Humanos , Animais , Masculino , Feminino , Parasitos , Columbidae , Paquistão/epidemiologia , Prevalência , Animais Selvagens
4.
Braz. j. biol ; 83: e248032, 2023. graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278557

RESUMO

Abstract A new species of nematode parasite of the subfamily Pudicinae (Heligmosomoidea: Heligmonellidae) is described from the small intestine of Proechimys simonsi (Rodentia: Echimyidae) from the locality of Nova Cintra in the municpality of Rodrigues Alves, Acre state, Brazil. The genus Pudica includes 15 species parasites of Neotropical rodents of the families Caviidae, Ctenomyidae, Dasyproctidae, Echimyidae, Erethizontidae, and Myocastoridae. Four species of this nematode were found parasitizing three different species rodents of the genus Proechimys in the Amazon biome. Pudica wandiquei n. sp. can be differentiated from all other Pudica species by the distance between the ends of rays 6 and 8 and the 1-3-1 pattern of the caudal bursa in both lobes.


Resumo Uma nova espécie de nematódeo da subfamília Pudicinae (Heligmosomoidea: Heligmonellidae) é descrito parasitando o intestino delgado de Proechimys simonsi (Rodentia: Echimyidae) em Nova Cintra, município de Rodrigues Alves, Estado do Acre, Brasil. O gênero Pudica inclui 15 espécies parasitas de roedores Neotropicais das famílias: Caviidae, Ctenomyidae, Dasyproctidae, Echimyidae, Erethizontidae e Myocastoridae. Destas, quatro espécies de nematódeos foram encontradas parasitando três diferentes espécies do roedor Proechimys no bioma Amazônia. Pudica wandiquei n. sp. é diferente das outras espécies de Pudica pela distância entre os raios 6 e 8 e pelo tipo da bolsa caudal, que é 1-3-1 em ambos os lados.


Assuntos
Animais , Parasitos , Trichostrongyloidea , Nematoides , Roedores , Brasil
5.
PLoS One ; 17(8): e0271640, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35913975

RESUMO

Entamoeba are amoeboid extracellular parasites that represent an important group of organisms for which the regulatory networks must be examined to better understand how genes and functional processes are interrelated. In this work, we inferred the gene regulatory networks (GRNs) in four Entamoeba species, E. histolytica, E. dispar, E. nuttalli, and E. invadens, and the GRN topological properties and the corresponding biological functions were evaluated. From these analyses, we determined that transcription factors (TFs) of E. histolytica, E. dispar, and E. nuttalli are associated mainly with the LIM family, while the TFs in E. invadens are associated with the RRM_1 family. In addition, we identified that EHI_044890 regulates 121 genes in E. histolytica, EDI_297980 regulates 284 genes in E. dispar, ENU1_120230 regulates 195 genes in E. nuttalli, and EIN_249270 regulates 257 genes in E. invadens. Finally, we identified that three types of processes, Macromolecule metabolic process, Cellular macromolecule metabolic process, and Cellular nitrogen compound metabolic process, are the main biological processes for each network. The results described in this work can be used as a basis for the study of gene regulation in these organisms.


Assuntos
Entamoeba histolytica , Entamoeba , Entamebíase , Parasitos , Animais , Entamoeba/genética , Entamoeba histolytica/genética , Entamebíase/genética , Entamebíase/parasitologia , Fezes/parasitologia
6.
PLoS Pathog ; 18(8): e1010696, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35925884

RESUMO

As effector innate immune cells and as a host to the protozoan parasite Leishmania, macrophages play a dual role in antileishmanial immunoregulation. The 2 key players in this immunoregulation are the macrophage-expressed microRNAs (miRNAs) and the macrophage-secreted cytokines. miRNAs, as small noncoding RNAs, play vital roles in macrophage functions including cytokines and chemokines production. In the reverse direction, Leishmania-regulated cytokines alter miRNAs expression to regulate the antileishmanial functions of macrophages. The miRNA patterns vary with the time and stage of infection. The cytokine-regulated macrophage miRNAs not only help parasite elimination or persistence but also regulate cytokine production from macrophages. Based on these observations, we propose a novel immunoregulatory framework as a scientific rationale for antileishmanial therapy.


Assuntos
Antiprotozoários , Leishmania , Leishmaniose , MicroRNAs , Parasitos , Animais , Antiprotozoários/metabolismo , Citocinas/metabolismo , Humanos , Leishmania/metabolismo , Leishmaniose/metabolismo , Macrófagos , MicroRNAs/metabolismo , Parasitos/metabolismo
7.
PLoS One ; 17(8): e0271529, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35925986

RESUMO

Captive environments trigger the propagation and multiplication of parasites among different reptile species, thus weakening their immune response and causing infections and diseases. Technological advances of convolutional neural networks have opened a new field for detecting and classifying diseases which have shown great potential to overcome the shortcomings of manual detection performed by experts. Therefore, we propose an approach to identify six captive reptiles parasitic agents (Ophionyssus natricis, Blastocystis sp, Oxiurdo egg, Rhytidoides similis, Strongyloides, Taenia) or the absence of such parasites from a microscope stool images dataset. Towards this end, we first use an image segmentation stage to detect the parasite within the image, which combines the Contrast Limited Adaptive Histogram Equalization (CLAHE) technique, the OTSU binarization method, and morphological operations. Then, we carry out a classification stage through MobileNet CNN under a transfer learning scheme. This method was validated on a stool image dataset containing 3616 images data samples and 26 videos from the six parasites mentioned above. The results obtained indicate that our transfer learning-based approach can learn a helpful representation from the dataset. We obtained an average accuracy of 94.26% across the seven classes (i.e., six parasitic agents and the absence of parasites), which statistically outperformed, at a 95% confidence level, a custom CNN trained from scratch.


Assuntos
Enteropatias Parasitárias , Parasitos , Animais , Enteropatias Parasitárias/diagnóstico , Enteropatias Parasitárias/veterinária , Microscopia , Redes Neurais de Computação , Répteis
8.
Nutrients ; 14(15)2022 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-35956387

RESUMO

Obesity is an epidemic causing a metabolic health crisis. Herein, the interactions between the gut prokaryotic and eukaryotic communities, metabolic comorbidities and diet were studied. Stool samples from 56 subjects, 47 with type III obesity and 9 with type II obesity and cardiovascular risk or metabolic disease, were assessed for the richness, diversity and ecology of the bacterial gut community through metagenomics, together with the study of the presence of common unicellular eukaryote parasites (Blastocystis sp., Dientamoeba fragilis and Giardia intestinalis) by qPCR. Clinical information regarding metabolic comorbidities and non-alcoholic hepatic fatty liver disease was gathered. To assess the quality of the patients' diet, each participant filled in three dietary questionnaires. The most prevalent parasite Blastocystis sp. (46.4%), together with D. fragilis (8.9%), was found to be associated with higher mean diversity indexes regarding non-colonized subjects; the opposite of that which was observed in those with G. intestinalis (16.1%). In terms of phyla relative abundance, with Blastocystis sp. and D. fragilis, very slight differences were observed; on the contrary, G. intestinalis was related to an increase in Bacteroidetes and Proteobacteria, and a decrease in Firmicutes and Actinobacteria, presenting the lowest Firmicutes/Bacteroidetes ratio. At genus level, Blastocystis sp. and/or D. fragilis was accompanied with an increase in Lactobacillus spp., and a decrease in Akkermansia spp., Bifidobacterium spp. and Escherichia spp., while G. intestinalis was associated with an increase in Bacteroides spp., and a decrease in Faecalibacterium spp., Prevotella spp. and Lactobacillus spp., and the highest Bacteroides spp./Prevotella spp. ratio. Participants with non-alcoholic hepatic fatty liver presented a higher Firmicutes/Bacteroidetes ratio, and those with type 2 diabetes displayed a significantly lower Faecalibacterium spp./Escherichia spp. ratio, due to an overrepresentation of the genus Escherichia spp. The presence of parasites was associated with variations in the richness, diversity and distribution of taxa in bacterial communities, confirming a gain in diversity associated with Blastocystis sp. and providing different functioning of the microbiota with a potential positive effect on comorbidities such as type 2 diabetes, insulin resistance and metabolic syndrome. Future basic and clinical studies should assess the beneficial or pathogenic effect of these eukaryotes on obese subjects and focus on deciphering whether they may imply a healthier metabolic profile.


Assuntos
Blastocystis , Diabetes Mellitus Tipo 2 , Obesidade Mórbida , Parasitos , Animais , Bactérias/genética , Fezes/microbiologia , Humanos
9.
Nat Commun ; 13(1): 4605, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35941154

RESUMO

Dogma holds that Toxoplasma gondii persists in neurons because neurons cannot clear intracellular parasites, even with IFN-γ stimulation. As several recent studies questioned this idea, here we use primary murine neuronal cultures from wild type and transgenic mice in combination with IFN-γ stimulation and parental and transgenic parasites to reassess IFN-γ dependent neuronal clearance of intracellular parasites. We find that neurons respond to IFN-γ and that a subset of neurons clear intracellular parasites via immunity regulated GTPases. Whole neuron reconstructions from mice infected with parasites that trigger neuron GFP expression only after full invasion reveal that ~50% of these T. gondii-invaded neurons no longer harbor parasites. Finally, IFN-γ stimulated human pluripotent stem cell derived neurons show an ~50% decrease in parasite infection rate when compared to unstimulated cultures. This work highlights the capability of human and murine neurons to mount cytokine-dependent anti-T. gondii defense mechanisms in vitro and in vivo.


Assuntos
Parasitos , Toxoplasma , Animais , GTP Fosfo-Hidrolases/metabolismo , Humanos , Interferon gama/metabolismo , Camundongos , Neurônios/metabolismo , Parasitos/metabolismo , Toxoplasma/metabolismo
10.
J Helminthol ; 96: e60, 2022 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-35942907

RESUMO

The parasite biodiversity of mouse opossums in Brazil remains incompletely explored. We describe a new species of Subulura (Ascaridida: Subuluroidea) from the large intestine of the white-bellied woolly mouse opossum, Marmosa constantiae, based on the results of light and scanning electron microscopy (SEM). We also partially sequenced the mitochondrial cytochrome c oxidase I (MT-CO1) gene of the new species, using molecular phylogenetic analyses to determine its relationships within the Subuluroidea superfamily. As molecular data on subuluroid species are extremely limited, few inferences could be drawn from our phylogenies. Our SEM observations showed the detailed morphology of the cephalic extremity, precloacal pseudo-sucker, caudal papillae, phasmids and vulva. Subulura eliseae sp. n. differs from the other four Subulura parasites species of marsupials by the number of caudal papillae and the structure dimensions, and size of the spicule. Moreover, S. eliseae sp. n. has ten pairs of caudal papillae, which is unique compared to other species. We present morphometric and molecular data on this new species, contributing to future studies on subuluroids.


Assuntos
Ascaridídios , Parasitos , Animais , Brasil , Feminino , Camundongos , Gambás , Filogenia , Floresta Úmida
11.
Front Immunol ; 13: 889645, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35911671

RESUMO

The tegument of Schistosoma mansoni is involved in essential functions for parasite survival and is known to stimulate immune responses in pre-clinical vaccine trials. Smtal-9, a member of the tegument-allergen-like (TAL) family, is one of the components of the tegument of schistosomula recognized by sera from immunized and protected mice. In this work, we assessed the role of Smtal-9 in parasite survival using the RNAi approach. Also, we cloned and expressed a recombinant form of Smtal-9 and evaluated its ability to induce protection in mice. Smtal-9 knockdown did not impact parasite survival in vitro, but significantly decreased schistosomula size. Additionally, significant reduction in both parasite and egg burdens were observed in mice inoculated with Smtal-9-knockdown schistosomula. Immunization using the Smtal-9 as an antigen conferred partial protection against challenge infection. Overall, our results indicate that Smtal-9 is a candidate target for drug and/or vaccine development due to its important role in parasite biology and survival.


Assuntos
Parasitos , Esquistossomose mansoni , Vacinas , Alérgenos/genética , Animais , Anticorpos Anti-Helmínticos , Antígenos de Helmintos/genética , Camundongos , Schistosoma mansoni , Desenvolvimento de Vacinas
12.
Front Cell Infect Microbiol ; 12: 942364, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35923798

RESUMO

Members of the WD40-repeat protein family can be found in all eukaryotic proteomes where they usually serve as interaction platforms for the assembly of large protein complexes and are therefore essential for the integrity of these complexes. In the malaria parasite Plasmodium falciparum, the WD40-repeat protein PfWLP1 has been shown to interact with members of distinct adhesion protein complexes in the asexual blood stages and gametocyte stages. In this study, we demonstrate that the presence of PfWLP1 is crucial for both the stability of these gametocyte-specific adhesion complexes as well as for gametocyte maturation and gametogenesis. Using reverse genetics, we generated a PfWLP1-knockdown parasite line for functional characterization of the protein. Knockdown of PfWLP1 resulted in a slight reduction of gametocyte numbers and significantly the impaired ability of the gametocytes to exflagellate. PfWLP1-knockdown further led to reduced protein levels of the Limulus coagulation factor C-like (LCCL)-domain proteins PfCCp1 and PfCCp2, which are key components of the adhesion complexes. These findings suggest that the interaction of PfWLP1 with members of the PfCCp-based adhesion complex ensures complex stability and thereby contributes to gametocyte viability and exflagellation.


Assuntos
Malária Falciparum , Parasitos , Animais , Malária Falciparum/parasitologia , Parasitos/metabolismo , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo
13.
Proc Biol Sci ; 289(1980): 20221106, 2022 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-35919996

RESUMO

Host density shapes infection risk through two opposing phenomena. First, when infective stages are subdivided among multiple hosts, greater host densities decrease infection risk through 'safety in numbers'. Hosts, however, represent resources for parasites, and greater host availability also fuels parasite reproduction. Hence, host density increases infection risk through 'density-dependent transmission'. Theory proposes that these phenomena are not disparate outcomes but occur over different timescales. That is, higher host densities may reduce short-term infection risk, but because they support parasite reproduction, may increase long-term risk. We tested this theory in a zooplankton-disease system with laboratory experiments and field observations. Supporting theory, we found that negative density-risk relationships (safety in numbers) sometimes emerged over short timescales, but these relationships reversed to 'density-dependent transmission' within two generations. By allowing parasite numerical responses to play out, time can shift the consequences of host density, from reduced immediate risk to amplified future risk.


Assuntos
Daphnia , Parasitos , Animais , Daphnia/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Reprodução , Zooplâncton/fisiologia
14.
BMC Plant Biol ; 22(1): 393, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35934696

RESUMO

BACKGROUND: Cuscuta japonica Choisy (Japanese dodder) is a parasitic weed that damages many plants and affects agricultural production. The haustorium of C. japonica plays a key role during parasitism in host plants; in contrast, some non-host plants effectively inhibit its formation. However, the metabolic differences between normal dodder in host plants and dodder inhibition in non-host plants are largely unknown. Here, we utilized an integrative analysis of transcriptomes and metabolomes to compare the differential regulatory mechanisms between C. japonica interacting with the host plant Ficus microcarpa and the non-host plant Mangifera indica. RESULTS: After parasitization for 24 h and 72 h, the differentially abundant metabolites between these two treatments were enriched in pathways associated with α-linolenic acid metabolism, linoleic acid metabolism, phenylpropanoid biosynthesis, and pyrimidine metabolism. At the transcriptome level, the flavor biosynthesis pathway was significantly enriched at 24 h, whereas the plant-pathogen interaction, arginine and proline metabolism, and MARK signaling-plant pathways were significantly enriched at 72 h, based on the differentially expressed genes between these two treatments. Subsequent temporal analyses identified multiple genes and metabolites that showed different trends in dodder interactions between the host and non-host plants. In particular, the phenylpropanoid biosynthesis pathway showed significant differential regulation between C. japonica in host and non-host plants. CONCLUSIONS: These results provide insights into the metabolic mechanisms of dodder-host interactions, which will facilitate future plant protection from C. japonica parasitism.


Assuntos
Cuscuta , Parasitos , Animais , Cuscuta/genética , Perfilação da Expressão Gênica , Parasitos/genética , Transcriptoma
15.
Proc Natl Acad Sci U S A ; 119(33): e2201247119, 2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-35939693

RESUMO

The virulence of Plasmodium falciparum, which causes the deadliest form of human malaria, is attributed to its ability to evade the human immune response. These parasites "choose" to express a single variant from a repertoire of surface antigens called PfEMP1, which are placed on the surface of the infected red cell. Immune evasion is achieved by switches in expression between var genes, each encoding a different PfEMP1 variant. While the mechanisms that regulate mutually exclusive expression of var genes are still elusive, antisense long-noncoding RNAs (lncRNAs) transcribed from the intron of the active var gene were implicated in the "choice" of the single active var gene. Here, we show that this lncRNA colocalizes with the site of var mRNA transcription and is anchored to the var locus via DNA:RNA interactions. We define the var lncRNA interactome and identify a redox sensor, P. falciparum thioredoxin peroxidase I (PfTPx-1), as one of the proteins associated with the var antisense lncRNA. We show that PfTPx-1 localizes to a nuclear subcompartment associated with active transcription on the nuclear periphery, in ring-stage parasite, when var transcription occurs. In addition, PfTPx-1 colocalizes with S-adenosylmethionine synthetase (PfSAMS) in the nucleus, and its overexpression leads to activation of var2csa, similar to overexpression of PfSAMS. Furthermore, we show that PfTPx-1 knockdown alters the var switch rate as well as activation of additional gene subsets. Taken together, our data indicate that nuclear PfTPx-1 plays a role in gene activation possibly by providing a redox-controlled nuclear microenvironment ideal for active transcription.


Assuntos
Malária Falciparum , Parasitos , RNA Longo não Codificante , Animais , Regulação da Expressão Gênica , Humanos , Malária Falciparum/genética , Malária Falciparum/parasitologia , Oxirredução , Parasitos/genética , Plasmodium falciparum/metabolismo , Regiões Promotoras Genéticas , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , RNA Longo não Codificante/genética , Ativação Transcricional
16.
Front Cell Infect Microbiol ; 12: 944748, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35909956

RESUMO

Chagas disease is a devastating neglected disease caused by the parasite Trypanosoma cruzi, which affects millions of people worldwide. The two anti-parasitic drugs available, nifurtimox and benznidazole, have a good efficacy against the acute stage of the infection. But this is short, usually asymptomatic and often goes undiagnosed. Access to treatment is mostly achieved during the chronic stage, when the cardiac and/or digestive life-threatening symptoms manifest. Then, the efficacy of both drugs is diminished, and their long administration regimens involve frequently associated adverse effects that compromise treatment compliance. Therefore, the discovery of safer and more effective drugs is an urgent need. Despite its advantages over lately used phenotypic screening, target-based identification of new anti-parasitic molecules has been hampered by incomplete annotation and lack of structures of the parasite protein space. Presently, the AlphaFold Protein Structure Database is home to 19,036 protein models from T. cruzi, which could hold the key to not only describe new therapeutic approaches, but also shed light on molecular mechanisms of action for known compounds. In this proof-of-concept study, we screened the AlphaFold T. cruzi set of predicted protein models to find prospective targets for a pre-selected list of compounds with known anti-trypanosomal activity using docking-based inverse virtual screening. The best receptors (targets) for the most promising ligands were analyzed in detail to address molecular interactions and potential drugs' mode of action. The results provide insight into the mechanisms of action of the compounds and their targets, and pave the way for new strategies to finding novel compounds or optimize already existing ones.


Assuntos
Doença de Chagas , Parasitos , Tripanossomicidas , Trypanosoma cruzi , Animais , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Humanos , Preparações Farmacêuticas , Tripanossomicidas/química , Tripanossomicidas/farmacologia
17.
Front Cell Infect Microbiol ; 12: 839216, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35967864

RESUMO

In human cutaneous leishmaniasis (HCL) caused by Leishmania (L.) major, the cutaneous lesions heal spontaneously and induce a Th1-type immunity that confers solid protection against reinfection. The same holds true for the experimental leishmaniasis induced by L. major in C57BL/6 mice where residual parasites persist after spontaneous clinical cure and induce sustainable memory immune responses and resistance to reinfection. Whether residual parasites also persist in scars of cured HCL caused by L. major is still unknown. Cutaneous scars from 53 volunteers with healed HCL caused by L. major were biopsied and the tissue sample homogenates were analyzed for residual parasites by four methods: i) microscope detection of amastigotes, ii) parasite culture by inoculation on biphasic medium, iii) inoculation of tissue exctracts to the footpad of BALB/c mice, an inbred strain highly susceptible to L. major, and iv) amplification of parasite kDNA by a highly sensitive real-time PCR (RT-PCR). Our results show that the scars of healed lesions of HCL caused by L. major do not contain detectable residual parasites, suggesting that this form likely induces a sterile cure at least within the scars. This feature contrasts with other Leishmania species causing chronic, diffuse, or recidivating forms of leishmaniasis where parasites do persist in healed lesions. The possibility that alternative mechanisms to parasite persistence are needed to boost and maintain long-term immunity to L. major, should be taken into consideration in vaccine development against L. major infection.


Assuntos
Leishmania major , Leishmaniose Cutânea , Parasitos , Animais , Cicatriz , Progressão da Doença , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Reinfecção
18.
Nat Commun ; 13(1): 4653, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35970835

RESUMO

Parasitic plants are worldwide threats that damage major agricultural crops. To initiate infection, parasitic plants have developed the ability to locate hosts and grow towards them. This ability, called host tropism, is critical for parasite survival, but its underlying mechanism remains mostly unresolved. To characterise host tropism, we used the model facultative root parasite Phtheirospermum japonicum, a member of the Orobanchaceae. Here, we show that strigolactones (SLs) function as host-derived chemoattractants. Chemotropism to SLs is also found in Striga hermonthica, a parasitic member of the Orobanchaceae, but not in non-parasites. Intriguingly, chemotropism to SLs in P. japonicum is attenuated in ammonium ion-rich conditions, where SLs are perceived, but the resulting asymmetrical accumulation of the auxin transporter PIN2 is diminished. P. japonicum encodes putative receptors that sense exogenous SLs, whereas expression of a dominant-negative form reduces its chemotropic ability. We propose a function for SLs as navigators for parasite roots.


Assuntos
Orobanchaceae , Parasitos , Animais , Fatores Quimiotáticos/metabolismo , Produtos Agrícolas/metabolismo , Compostos Heterocíclicos com 3 Anéis , Lactonas/metabolismo , Orobanchaceae/metabolismo , Parasitos/metabolismo , Raízes de Plantas/metabolismo , Tropismo Viral
20.
BMC Genomics ; 23(1): 489, 2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35787772

RESUMO

BACKGROUND: The evolution of parasites is often directly affected by the host's environment. Studies on the evolution of the same parasites in different hosts are of great interest and are highly relevant to our understanding of divergence. METHODS: Here we performed whole-genome sequencing of Parascaris univalens from different Equus hosts (horses, zebras and donkeys). Phylogenetic and selection analyses were performed to study the divergence and adaptability of P. univalens. RESULTS: At the genetic level, multiple lines of evidence indicate that P. univalens is mainly separated into two clades (horse-derived and zebra & donkey-derived). This divergence began 300-1000 years ago, and we found that most of the key enzymes related to glycolysis were under strong positive selection in zebra & donkey-derived roundworms, whereas the lipid-related metabolic system was under positive selection in horse-derived roundworms, indicating that the adaptive evolution of metabolism has occurred over the past few centuries. In addition, we found that some drug-related genes showed a significantly higher degree of selection in diverse populations. CONCLUSIONS: This work reports the adaptive evolution and divergence trend of P. univalens in different hosts for the first time. Its results indicate that the divergence of P. univalens is a continuous, dynamic process. Furthermore, the continuous monitoring of the effects of differences in nutritional and drug histories on the rapid evolution of roundworms is conducive to further understanding host-parasite interactions.


Assuntos
Ascaridoidea , Parasitos , Animais , Ascaridoidea/genética , Equidae/genética , Cavalos , Filogenia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...