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1.
Braz. j. biol ; 84: e258626, 2024. tab, mapas, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1384094

RESUMO

Ligula intestinalis is a cestode parasite that affects freshwater fish in different countries of the world. The current study aims to reveal the phylogenetic, genetic and haplotype diversity of mt-CO1 gene sequences sent to the NCBI database from different countries by using in-silico analysis. The 105 mt-CO1 (371 bp) gene sequences of L. intestinalis obtained from NCBI were used for bioinformatics analyses. Sequences were subjected to phylogenetic and haplotype analysis. As a result of the haplotype analysis of L. intestinalis, 38 haplotypes were obtained from 13 different countries. Hap24 constituted 44.76% of the obtained haplotype network. Changes in nucleotides between haplotypes occurred at 1-84 different points. China and Turkey have highest fixation index (Fst) values of 0.59761, while the lowest (-0.10526) was found between Russia and Turkey. This study provides a baseline for future studies on extensive scale on the epidemiology, ecological aspects, distribution pattern, transmission dynamics and population dispersion of L. intestinalis worldwide.


Ligula intestinalis é um parasita cestódeo que acomete peixes de água doce em diversos países do mundo. O presente estudo visa revelar a diversidade filogenética, genética e de haplótipos das sequências do gene mt-CO1 enviadas ao banco de dados do NCBI de diferentes países, por meio de análise in-silico. As sequências gênicas de 105 mt-CO1 (371 pb) de L. intestinalis obtidas do NCBI foram utilizadas para análises bioinformáticas. As sequências foram submetidas a análise filogenética e de haplótipos. Como resultado da análise de haplótipos de L. intestinalis, 38 haplótipos foram obtidos de 13 países diferentes. Hap24 constituiu 44,76% da rede de haplótipos obtida. Mudanças nos nucleotídeos entre os haplótipos ocorreram em 1-84 pontos diferentes. A China e a Turquia apresentam os maiores valores do índice de fixação (Fst), 0,59761, enquanto o menor (-0,10526) foi encontrado entre a Rússia e a Turquia. Este estudo fornece uma linha de base para futuros estudos em larga escala sobre epidemiologia, aspectos ecológicos, padrão de distribuição, dinâmica de transmissão e dispersão populacional de L. intestinalis em todo o mundo.


Assuntos
Animais , Parasitos , Filogenia , Variação Genética , Haplótipos , Peixes , Água Doce
2.
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
3.
Proc Biol Sci ; 290(1991): 20221752, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36695034

RESUMO

Parasite spillback from domestic animals can distort the balance between host and parasites in surrounding wildlife, with potential detrimental effects on wild populations. In aquatic environments, parasite spillback from aquaculture to wild salmon is one of the most contentious sustainability debates. In a 19 year time series of release group studies of Atlantic salmon, we demonstrated that (i) the effect of subjecting out-migrating salmon smolts to parasite treatment on marine survival has been reduced over a time, (ii) the relation between salmon lice levels in the out-migration route of the salmon and effect of treatment against the parasite is weak, but also (iii) the return rates in both treated and untreated groups of salmon are negatively correlated with salmon lice levels, and (iv) returns of wild salmon to the region are similarly negatively correlated with salmon lice levels during the out-migration year. Our study suggests that salmon lice can have a large effect on wild salmon populations that is not revealed with randomized control trials using antiparasitic drugs. This should be better accounted for when considering the impacts of farms on wild salmon populations.


Assuntos
Copépodes , Doenças dos Peixes , Parasitos , Salmo salar , Animais , Animais Selvagens , Aquicultura , Doenças dos Peixes/parasitologia
4.
PLoS Biol ; 21(1): e3001997, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36696650

RESUMO

Twenty years ago, the first transcriptome of the intraerythrocytic developmental cycle of the malaria parasite Plasmodium falciparum was published in PLOS Biology. Since then, transcriptomics studies have transformed the study of parasite biology.


Assuntos
Parasitos , Plasmodium falciparum , Animais , Plasmodium falciparum/genética , Transcriptoma/genética , Parasitos/genética , Perfilação da Expressão Gênica , Biologia
5.
PeerJ ; 11: e14700, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36699998

RESUMO

Background: This study aimed to evaluate the association between socio-demographic status, and hygienic habits among food handlers with intestinal parasitic infections. Methods: It was a cross-sectional study in which 112 participants were recruited, from Belgarn province of Saudi Arabia. The descriptive analysis was used to evaluate demographic data and categorical variables. The association between sociodemographic characteristics and Relative Risk regression analysis was performed for each investigated factor. p-value of <0.05, was assumed to be statistically significant. Results: One hundred and twelve food handlers with a mean age of 33.5 ± 9.2 years were included in this study. The food handlers were from 15 different countries (11 Asians and four Africans). The majority of the food handlers were cooks (87, 77.7%), and waiters and dish washers (24, 21.4%). Among them, 106 (94.6%) used uniforms, and gloves at work. In hand washing practices, 104 (92.9%) wash their hands with soap before handling and preparing food and eight (7.1%) wash without soap, 98 (87.5%) wash with soap before meals and 14 (12.5%) wash without soap, 105 (93.8%) wash with soap after visiting toilets and seven (6.2%) wash without soap. Twenty-five (42.3%) of infected food handlers are not used to trim their fingernails. Intestinal infection was observed in 59 (52.68%) participants with mean age (32.5 ± 8.1 years) for infected participants. Conclusion: In this study, food handlers had a high prevalence of intestinal parasites. Although some of the food handlers had a high level of education, the infection with intestinal parasites was detected. In addition to regular screening for intestinal parasites among food handlers, there is a need for educational programs on proper hygiene habits, modes of transmission and prevention of the infection.


Assuntos
Enteropatias Parasitárias , Parasitos , Animais , Humanos , Adulto Jovem , Adulto , Estudos Transversais , Arábia Saudita/epidemiologia , Sabões , Manipulação de Alimentos , Enteropatias Parasitárias/epidemiologia , Higiene
6.
J Helminthol ; 97: e13, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36700418

RESUMO

Mexico possesses a large diversity of amphibians partly due to its complex topography and transitional position between the Nearctic and Neotropical biogeographical regions. However, its helminth parasite fauna has been relatively poorly studied. Specimens of the Vaillant's frog, Lithobates vaillanti (Brocchi) were sampled in the tropical rain forest of Nahá, in the Chiapas Highlands, and examined for parasites. Two trematode species were collected from their hosts; morphologically, specimens were allocated to the genera Langeronia Caballero and Bravo-Hollis, 1949 and Haematoloechus Looss, 1899, respectively. Individuals were sequenced for two molecular markers (the mitochondrial cytochrome c oxidase gene, and the ribosomal gene 28S), and processed for morphological analyses, including scanning electron microscopy. The new evidence was not enough to accomplish the identification at species level of Langeronia sp. due to the lack of sequence data from the type localities of Langeronia parva Christian, 1970 and Langeronia macrocirra Caballero and Bravo-Hollis, 1949. Likewise, the newly generated data were useful to properly identify the adult specimens of lung flukes as Haematoloechus complexus Seely, 1906.


Assuntos
Helmintos , Parasitos , Trematódeos , Humanos , Animais , México , Ranidae/parasitologia , Filogenia
7.
PLoS Negl Trop Dis ; 17(1): e0011040, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36630476

RESUMO

People are infected with Leishmania donovani when the parasite is deposited in the dermis during the blood meal of the sand fly vector. Most infected people develop a subclinical latent infection, but some develop progressive visceral leishmaniasis. Malnutrition is a risk factor for the development of active VL. We previously demonstrated increased parasite dissemination from the skin to visceral organs in a murine model of malnutrition. Here we investigated the mechanism of early parasite dissemination. After delivery of L. donovani to the skin, we found enhanced capture of parasites by inflammatory monocytes and neutrophils in the skin of malnourished mice. However, parasite dissemination in malnourished mice was driven primarily by infected inflammatory monocytes, which showed increased CCR7 expression, greater intrinsic migratory capacity, and increased trafficking from skin to spleen. PGE2 production, which was increased at the site of skin infection, increased monocyte CCR7 expression and promoted CCR7-related monocyte-mediated early parasite dissemination in malnourished mice. Parasite dissemination in monocytes was reduced by inhibition of PGE2, knockdown or silencing of CCR7 in monocytes, and depletion of inflammatory monocytes through administration of diphtheria toxin to CSFR1-DTR transgenic mice that have monocyte-specific DT receptor expression. CCR7-driven trafficking of infected inflammatory monocytes through the lymph node was accompanied by increased expression of its ligands CCL19 and CCL21. These results show that the CCR7/PGE2 axis is responsible for the increased trafficking of L. donovani-infected inflammatory monocytes from the skin to the spleen in the malnourished host. Undernutrition and production of PGE2 are potential targets to reduce the risk of people developing VL. Nutritional interventions that target improved immune function and reduced PGE2 synthesis should be studied in people at risk of developing VL.


Assuntos
Leishmania donovani , Leishmaniose Visceral , Desnutrição , Parasitos , Camundongos , Animais , Leishmaniose Visceral/parasitologia , Monócitos , Receptores CCR7 , Dinoprostona , Desnutrição/complicações
8.
Parasit Vectors ; 16(1): 25, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36691084

RESUMO

BACKGROUND: Non-biting flies such as the house fly (Musca domestica), the Australian sheep blowfly (Lucilia cuprina) and the oriental latrine fly (Chrysomya megacephala) may carry many parasites. In the present study, we performed a systematic overview of the different species of parasites carried by non-biting flies, as well as of isolation methods, different geographical distribution, seasonality and risk assessment. METHODS: A meta-analysis was carried out with the aim to review the global prevalence of parasite transmission in non-biting flies. A total sample size of 28,718 non-biting flies reported in studies worldwide satisfied the predetermined selection criteria and was included in the quantitative analysis. RESULTS: The global prevalence of parasites in non-biting flies was 42.5% (95% confidence interval [CI] 31.9-53.2%; n = 15,888/28,718), with the highest prevalence found for non-biting flies in Africa (58.3%; 95% CI 47.4-69.3%; n = 9144/13,366). A total of 43% (95% CI 32.1-54.4%; n = 7234/15,282) of house flies (M. domestica), the fly species considered to be the most closely associated with humans and animals, were found with parasites. The prevalence of parasites in the intestine of non-biting flies was 37.1% (95% CI 22.7-51.5%; n = 1045/3817), which was significantly higher than the prevalence of parasites isolated from the body surface (35.1%; 95% CI 20.8-49.4%; n = 1199/3649; P < 0.01). Of the 27 reported parasites, a total of 20 known zoonotic parasites were identified, with an infection rate of 38.1% (95% CI 28.2-48.0%; n = 13,572/28,494). CONCLUSIONS: This study provides a theoretical basis for the public health and ecological significance of parasites transmitted by non-biting flies.


Assuntos
Dípteros , Moscas Domésticas , Parasitos , Humanos , Animais , Prevalência , Austrália , Dípteros/parasitologia , Calliphoridae
9.
PLoS One ; 18(1): e0258009, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36693052

RESUMO

Associations between genetic variants and susceptibility to infections have long been studied in free-living hosts so as to infer the contemporary evolutionary forces that shape the genetic polymorphisms of immunity genes. Despite extensive studies of proteins interacting with pathogen-derived ligands, such as MHC (major histocompatilbility complex) or TLR (Toll-like receptors), little is known about the efferent arm of the immune system. Cytokines are signalling molecules that trigger and modulate the immune response, acting as a crucial link between innate and adaptive immunity. In the present study we investigated how genetic variation in cytokines in bank voles Myodes glareolus affects their susceptibility to infection by parasites (nematodes: Aspiculuris tianjensis, Heligmosomum mixtum, Heligmosomoides glareoli) and microparasites (Cryptosporidium sp, Babesia microti, Bartonella sp.). We focused on three cytokines: tumour necrosis factor (TNF), lymphotoxin alpha (LTα), and interferon beta (IFNß1). Overall, we identified four single nucleotide polymorphisms (SNPs) associated with susceptibility to nematodes: two located in LTα and two in IFNß1. One of those variants was synonymous, another located in an intron. Each SNP associated with parasite load was located in or next to a codon under selection, three codons displayed signatures of positive selection, and one of purifying selection. Our results indicate that cytokines are prone to parasite-driven selection and that non-coding variants, although commonly disregarded in studies of the genetic background of host-parasite co-evolution, may play a role in susceptibility to infections in wild systems.


Assuntos
Criptosporidiose , Cryptosporidium , Nematoides , Parasitos , Animais , Parasitos/genética , Citocinas/genética , Polimorfismo Genético
10.
Proc Natl Acad Sci U S A ; 120(5): e2219533120, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36693095

RESUMO

Toxoplasmosis is a neglected parasitic disease necessitating public health control. Host cell invasion by Toxoplasma occurs at different stages of the parasite's life cycle and is crucial for survival and establishment of infection. In tachyzoites, which are responsible for acute toxoplasmosis, invasion involves the formation of a molecular bridge between the parasite and host cell membranes, referred to as the moving junction (MJ). The MJ is shaped by the assembly of AMA1 and RON2, as part of a complex involving additional RONs. While this essential process is well characterized in tachyzoites, the invasion process remains unexplored in bradyzoites, which form cysts and are responsible for chronic toxoplasmosis and contribute to the dissemination of the parasite between hosts. Here, we show that bradyzoites invade host cells in an MJ-dependent fashion but differ in protein composition from the tachyzoite MJ, relying instead on the paralogs AMA2 and AMA4. Functional characterization of AMA4 reveals its key role for cysts burden during the onset of chronic infection, while being dispensable for the acute phase. Immunizations with AMA1 and AMA4, alone or in complex with their rhoptry neck respective partners RON2 and RON2L1, showed that the AMA1-RON2 pair induces strong protection against acute and chronic infection, while the AMA4-RON2L1 complex targets more selectively the chronic form. Our study provides important insights into the molecular players of bradyzoite invasion and indicates that invasion of cyst-forming bradyzoites contributes to cyst burden. Furthermore, we validate AMA-RON complexes as potential vaccine candidates to protect against toxoplasmosis.


Assuntos
Parasitos , Toxoplasma , Toxoplasmose , Animais , Toxoplasma/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Infecção Persistente , Toxoplasmose/metabolismo , Parasitos/metabolismo , Vacinação
11.
PeerJ ; 11: e14599, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36655052

RESUMO

Myxosporeans are widespread cnidarian parasites that usually parasitize fish as part of their complex life cycle, thus constituting a potential threat for the aquaculture industry. White seabream Diplodus sargus (L.) is a commercially valuable sparid fish reared in Southern European aquacultures. Nonetheless, knowledge on myxosporean infections potentially harming the sustainable production of this fish is extremely limited. In this study, a myxosporean survey was conducted on D. sargus specimens reared in two Southern Portuguese fish farms. Two coelozoic myxosporeans were detected infecting the gall bladder, and are herein reported based on microscopic and molecular procedures: Ceratomyxa sargus n. sp. and Zschokkella auratis Rocha et al., 2013, previously described from reared stocks of gilthead seabream Sparus aurata in the same geographic locality. Ceratomyxa sargus n. sp. is the 12th species of the genus to be reported from Southern European sparids, reinforcing a substantial radiation of Ceratomyxa within this fish family and geographic region. SSU rRNA-based Bayesian inference and maximum likelihood analyses revealed C. sargus n. sp. positioned separately from other sparid-infecting Ceratomyxa spp. reported from Southern European countries, demonstrating that this species does not share a more immediate common ancestor with its closest relatives based on host affinity and geography. The recognition of a novel sparid-infecting lineage within the Ceratomyxa clade strengthens the contention that this genus entered sparid fish multiple times, namely in the Southern European region. The identification of Zschokkella auratis infections in D. sargus demonstrates that host shift has occurred among sparids reared in the Southern Portuguese coast. This agrees with the broad host specificity that is usually attributed to this genus, and that may be suggested to be the outcome of the capacity of the Zschokkella morphotype to undergo host shift/switch based on our findings and the limited molecular data available for this genus. Thus, a better understanding of Zschokkella host-associated diversification and dispersal mechanisms requires the increasing availability of molecular data from infections of the same species occurring in multiple hosts and geographical locations.


Assuntos
Doenças dos Peixes , Myxozoa , Parasitos , Doenças Parasitárias em Animais , Perciformes , Dourada , Animais , Dourada/parasitologia , Vesícula Biliar/parasitologia , Teorema de Bayes , Filogenia , Doenças dos Peixes/epidemiologia , Doenças Parasitárias em Animais/epidemiologia , Myxozoa/genética
12.
Parasite ; 30: 1, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36656045

RESUMO

Terrestrial gastropods are hosts of a wide variety of metazoan parasites and can respond to parasite exposure in various ways. One of these defence mechanisms, the ability to trap parasites in the host shell, was previously thought to apply only against nematodes. During a field survey along an urbanisation gradient, we found that the shell of Cornu aspersum and Cepaea nemoralis can contain encapsulated trematode cercariae, with prevalences of 7% and 1%, respectively over the entire sample, and up to 47% at the local population level. To our knowledge, this is the first case study unambiguously showing that land snails can trap non-nematode parasites in their shell at non-negligible prevalences. Shell-encapsulation could be a more general defence mechanism than previously described, and more studies are needed to understand its importance and variability.


Title: Les gastéropodes terrestres peuvent piéger les cercaires de trématodes dans leur coquille : l'encapsulation comme réponse générale contre les parasites ? Abstract: Les gastéropodes terrestres sont les hôtes d'une grande variété de métazoaires parasites, et peuvent répondre de plusieurs façons à l'exposition parasitaire. L'un de ces mécanismes de défense, la capacité à piéger le parasite dans la coquille, semblait ne concerner que les nématodes. Lors d'un suivi de terrain le long d'un gradient d'urbanisation, nous avons observé que la coquille de Cornu aspersum et de Cepaea nemoralis pouvait contenir des cercaires de trématodes encapsulées, à des prévalences respectives de 7 % et 1 % sur l'ensemble de l'échantillon, et pouvant atteindre 47 % au niveau d'une population locale. À notre connaissance, ceci est la première étude montrant sans ambiguïté que les escargots terrestres peuvent piéger de façon significative des parasites autres que les nématodes dans leur coquille. L'encapsulation des parasites dans la coquille pourrait donc être un mécanisme de défense plus général que précédemment décrit, plus d'études étant nécessaires pour comprendre son importance et sa variabilité.


Assuntos
Parasitos , Trematódeos , Animais , Humanos , Trematódeos/fisiologia , Cercárias , Caramujos/parasitologia
13.
Sci Rep ; 13(1): 1054, 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36658208

RESUMO

Stable isotope analysis of individual compounds is emerging as a powerful tool to study nutrient origin and conversion in host-parasite systems. We measured the carbon isotope composition of amino acids and glucose in the cestode Schistocephalus solidus and in liver and muscle tissues of its second intermediate host, the three-spined stickleback (Gasterosteus aculeatus), over the course of 90 days in a controlled infection experiment. Similar linear regressions of δ13C values over time and low trophic fractionation of essential amino acids indicate that the parasite assimilates nutrients from sources closely connected to the liver metabolism of its host. Biosynthesis of glucose in the parasite might occur from the glucogenic precursors alanine, asparagine and glutamine and with an isotope fractionation of - 2 to - 3 ‰ from enzymatic reactions, while trophic fractionation of glycine, serine and threonine could be interpreted as extensive nutrient conversion to fuel parasitic growth through one-carbon metabolism. Trophic fractionation of amino acids between sticklebacks and their diets was slightly increased in infected compared to uninfected individuals, which could be caused by increased (immune-) metabolic activities due to parasitic infection. Our results show that compound-specific stable isotope analysis has unique opportunities to study host and parasite physiology.


Assuntos
Cestoides , Infecções por Cestoides , Doenças dos Peixes , Parasitos , Smegmamorpha , Animais , Humanos , Infecções por Cestoides/parasitologia , Isótopos de Carbono , Carbono , Aminoácidos , Cestoides/fisiologia , Smegmamorpha/parasitologia , Nutrientes , Interações Hospedeiro-Parasita , Doenças dos Peixes/parasitologia
14.
Proc Biol Sci ; 290(1990): 20221966, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36598014

RESUMO

Rapid evolutionary change during range expansions can lead to diverging range core and front populations, with the emergence of dispersal syndromes (coupled responses in dispersal and life-history traits). Besides intraspecific effects, range expansions may be impacted by interspecific interactions such as parasitism. Yet, despite the potentially large impact of parasites imposing additional selective pressures on the host, their role on range expansions remains largely unexplored. Using microcosm populations of the ciliate Paramecium caudatum and its bacterial parasite Holospora undulata, we studied experimental range expansions under parasite presence or absence. We found that the interaction of range expansion and parasite treatments affected the evolution of host dispersal syndromes. Namely, front populations showed different associations of population growth parameters and swimming behaviours than core populations, indicating divergent evolution. Parasitism reshaped trait associations, with hosts evolved in the presence of the parasite exhibiting overall increased resistance and reduced dispersal. Nonetheless, when comparing infected range core and front populations, we found a positive association, suggesting joint evolution of resistance and dispersal at the front. We conclude that host-parasite interactions during range expansions can change evolutionary trajectories; this in turn may feedback on the ecological dynamics of the range expansion and parasite epidemics.


Assuntos
Traços de História de Vida , Parasitos , Animais , Síndrome , Interações Hospedeiro-Parasita , Dinâmica Populacional , Evolução Biológica
15.
Proc Biol Sci ; 290(1990): 20221506, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36598020

RESUMO

Parasites face a trade-off if the highest quality hosts are also most resistant to exploitation. For brood parasites, well-defended host nests may be both harder to parasitize and harder to predate, leading to better survival of parasitic chicks. This trade-off could be accentuated if brood-parasitic adaptations to reduce front-line defences of hosts, such as mimicry of hawks by Cuculus cuckoos, do not deter hosts which aggressively mob raptors. Here we investigate the costs and benefits to the African cuckoo (Cuculus gularis) of specializing on a highly aggressive host species, the fork-tailed drongo (Dicrurus adsimilis). Field experiments showed that drongos strongly attacked and mobbed both cuckoo and hawk models, implying that hawk mimicry does not deter front-line defences against African cuckoos. Attacks on cuckoo and hawk models generally declined after the egg stage but attacks on snake models sharply increased, suggesting drongos may treat hawks more like cuckoos than predators. We suggest that the cost to cuckoos of parasitizing an aggressive host may be alleviated by subsequent benefits to their offspring, since drongo nests survived better than nests of other species with similar nesting ecology. These results are indicative of a trade-off between host quality and susceptibility for a brood parasite.


Assuntos
Falcões , Parasitos , Passeriformes , Animais , Comportamento de Nidação , Galinhas
16.
Sensors (Basel) ; 23(2)2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36679358

RESUMO

Centuries of scientific breakthroughs have brought us closer to understanding and managing the spread of parasitic diseases. Despite ongoing technological advancements in the detection, treatment, and control of parasitic illnesses, their effects on animal and human health remain a major concern worldwide. Aptamers are single-stranded oligonucleotides whose unique three-dimensional structures enable them to interact with high specificity and affinity to a wide range of targets. In recent decades, aptamers have emerged as attractive alternatives to antibodies as therapeutic and diagnostic agents. Due to their superior stability, reusability, and modifiability, aptamers have proven to be effective bioreceptors for the detection of toxins, contaminants, biomarkers, whole cells, pathogens, and others. As such, they have been integrated into a variety of electrochemical, fluorescence, and optical biosensors to effectively detect whole parasites and their proteins. This review offers a summary of the various types of parasite-specific aptamer-based biosensors, their general mechanisms and their performance.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Parasitos , Animais , Humanos , Parasitos/metabolismo , Aptâmeros de Nucleotídeos/química , Biomarcadores , Anticorpos , Técnicas Biossensoriais/métodos
17.
Science ; 379(6628): eabl3837, 2023 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-36634189

RESUMO

Ancestral signaling pathways serve critical roles in metazoan development, physiology, and immunity. We report an evolutionary interspecies communication pathway involving a central Ixodes scapularis tick receptor termed Dome1, which acquired a mammalian cytokine receptor motif exhibiting high affinity for interferon-gamma (IFN-γ). Host-derived IFN-γ facilitates Dome1-mediated activation of the Ixodes JAK-STAT pathway. This accelerates tick blood meal acquisition and development while upregulating antimicrobial components. The Dome1-JAK-STAT pathway, which exists in most Ixodid tick genomes, regulates the regeneration and proliferation of gut cells-including stem cells-and dictates metamorphosis through the Hedgehog and Notch-Delta networks, ultimately affecting Ixodes vectorial competence. We highlight the evolutionary dependence of I. scapularis on mammalian hosts through cross-species signaling mechanisms that dually influence arthropod immunity and development.


Assuntos
Ixodes , Parasitos , Animais , Transdução de Sinais , Janus Quinases/genética , Fatores de Transcrição STAT/genética , Ixodes/genética , Interferon gama , Mamíferos
18.
Proc Biol Sci ; 290(1991): 20222204, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36651047

RESUMO

Helminth transmission and morbidity are dependent on the number of mature parasites within a host; however, observing adult worms is impossible for many natural infections. An outstanding challenge is therefore relating routine diagnostics, such as faecal egg counts, to the underlying worm burden. This relationship is complicated by density-dependent fecundity (egg output per worm reduces due to crowding at high burdens) and the skewed distribution of parasites (majority of helminths aggregated in a small fraction of hosts). We address these questions for the carcinogenic liver fluke Opisthorchis viverrini, which infects approximately 10 million people across Southeast Asia, by analysing five epidemiological surveys (n = 641) where adult flukes were recovered. Using a mechanistic model, we show that parasite fecundity varies between populations, with surveys from Thailand and Laos demonstrating distinct patterns of egg output and density-dependence. As the probability of observing faecal eggs increases with the number of mature parasites within a host, we quantify diagnostic sensitivity as a function of the worm burden and find that greater than 50% of cases are misdiagnosed as false negative in communities close to elimination. Finally, we demonstrate that the relationship between observed prevalence from routine diagnostics and true prevalence is nonlinear and strongly influenced by parasite aggregation.


Assuntos
Helmintos , Parasitos , Trematódeos , Animais , Fertilidade , Contagem de Ovos de Parasitas , Fezes/parasitologia
19.
Sci Rep ; 13(1): 976, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36653420

RESUMO

Heartworm disease, caused by Dirofilaria immitis, remains a significant threat to canines and felines. The development of parasites resistant to macrocyclic lactones (ML) has created a significant challenge to the control of the infection. The goal of this study was to determine if mice lacking a functional immune response would be susceptible to D. immitis. Immunodeficient NSG mice were susceptible to the infection, sustaining parasites for at least 15 weeks, with infective third-stage larvae molting and developing into the late fourth-stage larvae. Proteomic analysis of host responses to the infection revealed a complex pattern of changes after infection, with at least some of the responses directed at reducing immune control mechanisms that remain in NSG mice. NSG mice were infected with isolates of D. immitis that were either susceptible or resistant to MLs, as a population. The susceptible isolate was killed by ivermectin whereas the resistant isolate had improved survivability, while both isolates were affected by moxidectin. It was concluded that D. immitis survives in NSG mice for at least 15 weeks. NSG mice provide an ideal model for monitoring host responses to the infection and for testing parasites in vivo for susceptibility to direct chemotherapeutic activity of new agents.


Assuntos
Doenças do Gato , Dirofilaria immitis , Doenças do Cão , Parasitos , Animais , Cães , Gatos , Camundongos , Dirofilaria immitis/fisiologia , Proteômica , Doenças do Cão/parasitologia
20.
Parasit Vectors ; 16(1): 19, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36653864

RESUMO

BACKGROUND: Although wild ungulate populations are heavily monitored throughout Europe, we understand little of how parasites affect population dynamics, and there is no systematic, long-term monitoring of parasite diversity and parasite loads. Such monitoring is in part hampered by a lack of time- and cost-effective assay methodologies with high sensitivity and good taxonomic resolution. DNA metabarcoding has been successfully used to characterize the parasitic nemabiome with high taxonomic resolution in a variety of wild and domestic hosts. However, in order to implement this technique in large-scale, potentially non-invasive monitoring of gastrointestinal parasitic nematodes (GIN), protocol optimization is required to maximize biodiversity detection, whilst maintaining time- and cost-effectiveness. METHODS: Faecal samples were collected from a wild moose population and GIN communities were characterized and quantified using both parasitological techniques (egg and larva counting) and DNA metabarcoding of the ITS2 region of rDNA. Three different isolation methods were compared that differed in the volume of starting material and cell lysis method. RESULTS: Similar nematode faunas were recovered from all samples using both parasitological and metabarcoding methods, and the approaches were largely congruent. However, metabarcoding assays showed better taxonomic resolution and slightly higher sensitivity than egg and larvae counts. The metabarcoding was not strictly quantitative, but the proportion of target nematode sequences recovered was correlated with the parasitologically determined parasite load. Species detection rates in the metabarcoding assays were maximized using a DNA isolation method that included mechanical cell disruption and maximized the starting material volume. CONCLUSIONS: DNA metabarcoding is a promising technique for the non-invasive, large-scale monitoring of parasitic GINs in wild ungulate populations, owing to its high taxonomic resolution, increased assay sensitivity, and time- and cost-effectiveness. Although metabarcoding is not a strictly quantitative method, it may nonetheless be possible to create a management- and conservation-relevant index for the host parasite load from this data. To optimize the detection rates and time- and cost-effectiveness of metabarcoding assays, we recommend choosing a DNA isolation method that involves mechanical cell disruption and maximizes the starting material volume.


Assuntos
Cervos , Enteropatias Parasitárias , Nematoides , Parasitos , Animais , Parasitos/genética , Animais Selvagens , DNA Ribossômico/genética , Enteropatias Parasitárias/parasitologia , Biodiversidade , Código de Barras de DNA Taxonômico/métodos
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