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1.
Zootaxa ; 4768(1): zootaxa.4768.1.2, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33056533

RESUMO

A rhizocephalan parasite of the hermit crab Pagurus minutus Hess, 1865 (Decapoda, Paguridae) is described from Russian waters using morphological and molecular methods. Partial sequences of the mitochondrial cytochrome c oxidase subunit I gene (COI) were used as a genetic marker. We refer this species to Peltogaster reticulata Shiino, 1943 (Rhizocephala, Peltogastridae) based on its morphological description, since genetic data for the species from its type locality are lacking. The species can be distinguished from its known congeners by the reticular pattern of the external cuticle. Peltogaster reticulata is the sister taxon to P. postica Yoshida Osawa, 2011 (in Yoshida et al. 2011), inhabiting the same host in southwestern Japan. The complete larval development of Peltogaster reticulata, including five naupliar and one cypris stage, is described and illustrated using SEM.


Assuntos
Anomuros , Parasitos , Thoracica , Animais , Japão , Federação Russa
2.
Vet Rec ; 187(7): 279, 2020 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-33008988

Assuntos
Parasitos , Animais
4.
Rev Inst Med Trop Sao Paulo ; 62: e64, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32901761

RESUMO

Intestinal mucins are the first line of defense against microorganisms. Although knowledge about the mechanisms involved in the establishment of intestinal protozoa is limited, there is evidence that these parasites produce lectin-like molecules and glycosidases, that exert both, constitutive and secretory functions, promoting the establishment of these microorganisms. In the present review, we analyse the main interactions between mucins of the host intestine and the four main protozoan parasites in humans and their implications in intestinal colonization. There are lectin-like molecules that contain complex oligosaccharide structures and N-acetylglucosamine (GlcNAc), mannose and sialic acid as main components, which are excreted/secreted by Giardia intestinalis, and recognized by the host using mannose-binding lectins (MBL). Entamoeba histolytica and Cryptosporidium spp. express the lectin galactose/N-acetyl-D-galactosamine, which facilitates their adhesion to cells. In Cryptosporidium, the glycoproteins gp30, gp40/15 and gp900 and the glycoprotein lectin CpClec are involved in protozoan adhesion to intestinal cells, forming an adhesion-attack complex. G. intestinalis and E. histolytica can also produce glycosidases such as ß-N-acetyl-D-glucosaminidase, α-d-glucosidase, ß-d-galactosidase, ß-l-fucosidase, α-N-acetyl-d-galactosaminidase and ß-mannosidase. In Blastocystis, α-D-mannose, α-D-glucose, GlcNAc, α-D-fucose, chitin and sialic acid that have been identified on their surface. Fucosidases, hexosaminidases and polygalacturonases, which may be involved in the mucin degradation process, have also been described in the Blastocystis secretoma. Similarly, symbiotic coexistence with the intestinal microbiota promotes the survival of parasites facilitating cell invasion and nutrients obtention. Furthermore, it is necessary to identify and characterize more glycosidases, which have been only partially described by in silico analyses of the parasite genome.


Assuntos
Criptosporidiose , Cryptosporidium , Glicoproteínas , Mucinas , Parasitos , Animais , Criptosporidiose/parasitologia , Cryptosporidium/parasitologia , Entamoeba/patogenicidade , Glicoproteínas/metabolismo , Glicosídeo Hidrolases , Humanos , Intestinos/microbiologia , Lectinas , Parasitos/patogenicidade
5.
Oecologia ; 194(1-2): 65-74, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32876762

RESUMO

Parasites are ecologically ubiquitous and, by modifying the physiology and behavior of their host organisms, act as key regulators of the dynamics and stability of ecosystems. It is, however, as yet unclear how parasitic relationships will act to moderate or accelerate the ecological impacts of global climate change. Here, we explore experimentally how the effects of parasites on both the physiology and behavior of their hosts can be moderated by warming, utilising a well-established aquatic host-parasite model system-the ecologically important amphipod Gammarus duebeni and its acanthocephalan parasite Polymorphus minutus. We show that, while only warming affected measured components of host physiology, parasite infection and warming both supressed predator-avoidance behavior of the host independently, yet in a similar manner. Six degrees of warming altered geotactic behaviors to the same extent as infection with behavior-manipulating parasites. These results indicate a novel mechanism by which parasites impact their ecosystems that could be critical to predicting the ecological impacts of warming. Our findings highlight the need for holistic knowledge of interaction networks, incorporating multiple interaction types and behaviors, to predict the effects of both warming and parasitism on the dynamics and stability of ecosystems.


Assuntos
Acantocéfalos , Anfípodes , Infecções , Parasitos , Animais , Ecossistema , Interações Hospedeiro-Parasita
6.
Proc Biol Sci ; 287(1935): 20201831, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32962545

RESUMO

Urban habitats can shape interactions between hosts and parasites by altering not only exposure rates but also within-host processes. Artificial light at night (ALAN) is common in urban environments, and chronic exposure can impair host immunity in ways that may increase infection. However, studies of causal links between this stressor, immunity, and infection dynamics are rare, particularly in migratory animals. Here, we experimentally tested how ALAN affects cellular immunity and haemosporidian parasite intensity across the annual cycle of migrant and resident subspecies of the dark-eyed junco (Junco hyemalis). We monitored an experimental group exposed to light at night and a control group under natural light/dark cycles as they passed through short days simulating early spring to longer days simulating the breeding season, followed by autumn migration. Using generalized additive mixed models, we show that ALAN increased inflammation, and leucocyte counts were greatest in early spring and autumn. At the start of the experiment, few birds had active infections based on microscopy, but PCR revealed many birds had chronic infections. ALAN increased parasitaemia across the annual cycle, with strong peaks in spring and autumn that were largely absent in control birds. As birds were kept in indoor aviaries to prevent vector exposure, this increased parasitaemia indicates relapse of chronic infection during costly life-history stages (i.e. reproduction). Although the immunological and parasitological time series were in phase for control birds, cross-correlation analyses also revealed ALAN desynchronized leucocyte profiles and parasitaemia, which could suggest a general exaggerated inflammatory response. Our study shows how a common anthropogenic influence can shape within-host processes to affect infection dynamics.


Assuntos
Migração Animal , Aves Canoras/parasitologia , Animais , Cruzamento , Parasitemia , Parasitos , Recidiva , Estações do Ano
7.
Sci Total Environ ; 738: 140339, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32806342

RESUMO

Studies have demonstrated the role of acanthocephalan as environmental bioindicators. The dynamics in the parasite-host relationship that define the patterns of distribution of trace metals in parasites and, in its host, are extremely variable. In addition, the neotropical region, which is a major maintainer of the biodiversity of fish and parasites, remains little explored in this subject. Therefore, our objective was to analyze and compare the concentration of Cadmium (Cd) in the tissues of Prochilodus lineatus and Serrasalmus marginatus collected from Baía and Paraná rivers, as well as to assess the use of acanthocephalan as environmental bioindicators of pollution and their Cd bioaccumulation capacity. We collected 53 fish, 20 specimens of Prochilodus lineatus from Paraná River and 17 from Baía River, in addition to 16 specimens of Serrasalmus marginatus from Baía River, in September 2017 and March 2018. Tissues of the fish along with their parasites were subjected a Cd concentration analysis by Atomic Absorption Spectroscopy. The results revealed that the parasites had higher concentrations than all the tissues of S. marginatus, P. lineatus from Baía River and Paraná River. The high Cd concentrations in these parasites derived from their bioaccumulation capacity, because of the absorption of nutrients directly from the intestinal content of the fish through the tegument, as well as for the presence of Cd on the surface waters of Praná River floodplain. Besides that, the Coefficient of Spearman Rank Correlation showed that the infrapopulation size seems to affect Cd bioaccumulation in the parasites, smaller infrapopulations demonstrate a higher accumulation capacity compared to the larger ones. With that, we concluded that the two acanthocephalans species analyzed in this study have a good capacity for Cd accumulation, and can be used as accumulation indicators of trace-metal pollution. Accumulation indicators provide important information on the biological availability of pollutants.


Assuntos
Caraciformes , Parasitos , Animais , Brasil , Cádmio/análise , Biomarcadores Ambientais , Monitoramento Ambiental , Rios
8.
PLoS One ; 15(8): e0231803, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817660

RESUMO

Taiep rat is a myelin mutant with a progressive motor syndrome characterized by tremor, ataxia, immobility episodes, epilepsy and paralysis of the hindlimbs. Taiep had an initial hypomyelination followed by a progressive demyelination associated with an increased expression of some interleukins and their receptors. The pathology correlated with an increase in nitric oxide activity and lipoperoxidation. In base of the above evidences taiep rat is an appropriate model to study neuroimmune interactions. The aim of this study was to analyze the immune responses in male taiep rats after acute infection with Trichinella spiralis. Our results show that there is an important decrease in the number of intestinal larvae in the taiep rat with respect to Sprague-Dawley control rats. We also found differences in the percentage of innate and adaptive immune cell profile in the mesenteric lymphatic nodes and the spleen that correlated with the demyelination process that took place on taiep subjects. Finally, a clear pro-inflammatory cytokine pattern was seen on infected taiep rats, that could be responsible of the decrement in the number of larvae number. These results sustain the theory that neuroimmune interaction is a fundamental process capable of modulating the immune response, particularly against the parasite Trichinella spiralis in an animal model of progressive demyelination due to tubulinopathy, that could be an important mechanism for the clinical course of autoimmune diseases associated with parasite infection.


Assuntos
Bainha de Mielina/genética , Bainha de Mielina/metabolismo , Trichinella spiralis/patogenicidade , Animais , Doenças Desmielinizantes/patologia , Modelos Animais de Doenças , Masculino , Parasitos , Ratos , Ratos Mutantes/imunologia , Ratos Sprague-Dawley/genética , Ratos Sprague-Dawley/imunologia , Tremor/patologia , Trichinella spiralis/metabolismo
9.
Mar Pollut Bull ; 158: 111399, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32753184

RESUMO

We quantified the incidence of microplastics in the gut contents of the European sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) in the Northwestern Mediterranean Sea and tested which variables influence this abundance, including the prevalence of parasites (i.e., trematoda larvae and nematodes). We detected a 58% occurrence of microplastics ingestion in sardines and a 60% in anchovies. With respect to sardines, the individuals with lower body conditions were found to have the highest microplastics ingestion probabilities, whereas in anchovies such probabilities were observed in individuals with higher gonadosomatic indices and smaller size. The areas with the highest microplastics ingestion probabilities were the Gulf of Alicante for sardines and the Gulf of Lion - Ebro Delta for anchovies. Both species showed a positive relationship between parasites and microplastics ingestion. These results highlight that both parasitism and ingestion of microplastics are concerns for the health of marine stocks and human consumers.


Assuntos
Parasitos , Poluentes Químicos da Água/análise , Animais , Peixes , Humanos , Mar Mediterrâneo , Microplásticos , Plásticos
10.
BMC Ecol ; 20(1): 47, 2020 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-32814584

RESUMO

BACKGROUND: Forest habitats are important biodiversity refuges for a wide variety of bird species. Parasitism may modulate host species presence and abundance, and parasite effects can change according to forest management practices. Such processes are not well studied in vector-borne avian haemosporidians. We analyzed the effects of forest management on bird-dipteran-haemosporidian interactions, using seven common bird species in managed and unmanaged beech forest habitats in northeastern Germany. We assumed that forest structural heterogeneity affects parasite population parameters in avian hosts (i.e., prevalence and parasitemia), through its effect on the condition of the avian host but also through varying vector abundances. RESULTS: Parasite prevalence was high (about 80%) and homogeneous across different beech forest categories (i.e., young, old, unmanaged) and for all bird species, except Erithacus rubecula (35%). Parasitemia varied across bird species but not across forest categories within each avian species (lowest parasitemia were found in E. rubecula, Turdus merula, and Turdus philomelos). In our study system, we found that vector abundance was not the main driver of parasite dynamics. We found that forest structure affects parasite infection probability directly and potentially host condition via available resources that have to be used either to combat infections (i.e., high parasitemia) or to maintain a good body condition. CONCLUSIONS: The effects of each of the predictors were bird species-specific, and we found that Diptera vectors were not the foremost influence in our host-vector-parasite system. Effects of forest habitat variables indicated that for most bird species in this study, habitat regulation of infection probability was more likely (i.e., E. rubecula, Fringilla coelebs, Sylvia atricapilla), whereas for Parus major habitat characteristics impacted first individuals' body condition and subsequently the probability of infection. Our findings emphasize the need of species-specific analyses and to use continuous forest structural parameters (e.g., the proportion of gap, south facing aspect) to better understand habitat and land use effects on host-vector-parasite dynamics.


Assuntos
Haemosporida , Parasitos , Passeriformes , Animais , Florestas , Alemanha
11.
Annu Rev Phytopathol ; 58: 1-22, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32853101

RESUMO

Gall-inducing insects and nematodes engage in sophisticated interactions with their host plants. These parasites can induce major morphological and physiological changes in host roots, leaves, and other tissues. Sedentary endoparasitic nematodes, root-knot and cyst nematodes in particular, as well as gall-inducing and leaf-mining insects, manipulate plant development to form unique organs that provide them with food from feeding cells. Sometimes, infected tissues may undergo a developmental switch resulting in the formation of aberrant and spectacular structures (clubs or galls). We describe here the complex interactions between these plant-reprogramming sedentary endoparasites and their infected hosts, focusing on similarities between strategies of plant manipulation. We highlight progress in our understanding of the host plant response to infection and focus on the nematode and insect molecules secreted in planta. We suggest thatlooking at similarities may identify convergent and conserved strategies and shed light on the promise they hold for the development of new management strategies in agriculture and forestry.


Assuntos
Parasitos , Tylenchoidea , Animais , Interações Hospedeiro-Parasita , Insetos , Doenças das Plantas , Raízes de Plantas , Plantas
12.
Proc Biol Sci ; 287(1932): 20200347, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32781954

RESUMO

Circadian clocks coordinate organisms' activities with daily cycles in their environment. Parasites are subject to daily rhythms in the within-host environment, resulting from clock-control of host activities, including immune responses. Parasites also exhibit rhythms in their activities: the timing of within-host replication by malaria parasites is coordinated to host feeding rhythms. Precisely which host feeding-related rhythm(s) parasites align with and how this is achieved are unknown. Understanding rhythmic replication in malaria parasites matters because it underpins disease symptoms and fuels transmission investment. We test if rhythmicity in parasite replication is coordinated with the host's feeding-related rhythms and/or rhythms driven by the host's canonical circadian clock. We find that parasite rhythms coordinate with the time of day that hosts feed in both wild-type and clock-mutant hosts, whereas parasite rhythms become dampened in clock-mutant hosts that eat continuously. Our results hold whether infections are initiated with synchronous or with desynchronized parasites. We conclude that malaria parasite replication is coordinated to rhythmic host processes that are independent of the core-clock proteins PERIOD 1 and 2; most likely, a periodic nutrient made available when the host digests food. Thus, novel interventions could disrupt parasite rhythms to reduce their fitness, without interference by host clock-controlled homeostasis.


Assuntos
Relógios Circadianos , Interações Hospedeiro-Parasita/fisiologia , Plasmodium chabaudi/fisiologia , Animais , Ritmo Circadiano/fisiologia , Homeostase , Malária , Parasitos , Proteínas Circadianas Period
13.
Parasitol Res ; 119(10): 3145-3164, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32748037

RESUMO

Parasites and bacteria have co-evolved with humankind, and they interact all the time in a myriad of ways. For example, some bacterial infections result from parasite-dwelling bacteria as in the case of Salmonella infection during schistosomiasis. Other bacteria synergize with parasites in the evolution of human disease as in the case of the interplay between Wolbachia endosymbiont bacteria and filarial nematodes as well as the interaction between Gram-negative bacteria and Schistosoma haematobium in the pathogenesis of urinary bladder cancer. Moreover, secondary bacterial infections may complicate several parasitic diseases such as visceral leishmaniasis and malaria, due to immunosuppression of the host during parasitic infections. Also, bacteria may colonize the parasitic lesions; for example, hydatid cysts and skin lesions of ectoparasites. Remarkably, some parasitic helminths and arthropods exhibit antibacterial activity usually by the release of specific antimicrobial products. Lastly, some parasite-bacteria interactions are induced as when using probiotic bacteria to modulate the outcome of a variety of parasitic infections. In sum, parasite-bacteria interactions involve intricate processes that never cease to intrigue the researchers. However, understanding and exploiting these interactions could have prophylactic and curative potential for infections by both types of pathogens.


Assuntos
Infecções Bacterianas/complicações , Filarioidea/microbiologia , Doenças Parasitárias/complicações , Schistosoma haematobium/microbiologia , Wolbachia/crescimento & desenvolvimento , Animais , Antibacterianos/uso terapêutico , Artrópodes/microbiologia , Humanos , Parasitos/microbiologia , Probióticos/uso terapêutico , Simbiose , Neoplasias da Bexiga Urinária/microbiologia , Neoplasias da Bexiga Urinária/parasitologia , Neoplasias da Bexiga Urinária/patologia
14.
Nat Commun ; 11(1): 4185, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826898

RESUMO

Adaptive responses to ecological uncertainty may affect the dynamics of interspecific interactions and shape the course of evolution within symbioses. Obligate avian brood parasites provide a particularly tractable system for understanding how uncertainty, driven by environmental variability and symbiont phenology, influences the evolution of species interactions. Here, we use phylogenetically-informed analyses and a comprehensive dataset on the behaviour and geographic distribution of obligate avian brood parasites and their hosts to demonstrate that increasing uncertainty in thermoregulation and parental investment of parasitic young are positively associated with host richness and diversity. Our findings are consistent with the theoretical expectation that ecological risks and environmental unpredictability should favour the evolution of bet-hedging. Additionally, these highly consistent patterns highlight the important role that ecological uncertainty is likely to play in shaping the evolution of specialisation and generalism in complex interspecific relationships.


Assuntos
Aves/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Parasitos/fisiologia , Incerteza , Animais , Biodiversidade , Coevolução Biológica , Aves/classificação , Clima , Comportamento de Nidação , Parasitos/classificação , Filogenia , Fatores de Risco , Especificidade da Espécie
15.
PLoS Med ; 17(8): e1003203, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32822347

RESUMO

BACKGROUND: Artemisinin resistance is threatening malaria control. We aimed to develop and test a human model of artemisinin-resistant (ART-R) Plasmodium falciparum to evaluate the efficacy of drugs against ART-R malaria. METHODS AND FINDINGS: We conducted 2 sequential phase 1, single-centre, open-label clinical trials at Q-Pharm, Brisbane, Australia, using the induced blood-stage malaria (IBSM) model, whereby healthy participants are intravenously inoculated with blood-stage parasites. In a pilot study, participants were inoculated (Day 0) with approximately 2,800 viable P. falciparum ART-R parasites. In a comparative study, participants were randomised to receive approximately 2,800 viable P. falciparum ART-R (Day 0) or artemisinin-sensitive (ART-S) parasites (Day 1). In both studies, participants were administered a single approximately 2 mg/kg oral dose of artesunate (AS; Day 9). Primary outcomes were safety, ART-R parasite infectivity, and parasite clearance. In the pilot study, 2 participants were enrolled between April 27, 2017, and September 12, 2017, and included in final analyses (males n = 2 [100%], mean age = 26 years [range, 23-28 years]). In the comparative study, 25 participants were enrolled between October 26, 2017, and October 18, 2018, of whom 22 were inoculated and included in final analyses (ART-R infected participants: males n = 7 [53.8%], median age = 22 years [range, 18-40 years]; ART-S infected participants: males n = 5 [55.6%], median age = 28 years [range, 22-35 years]). In both studies, all participants inoculated with ART-R parasites became parasitaemic. A total of 36 adverse events were reported in the pilot study and 277 in the comparative study. Common adverse events in both studies included headache, pyrexia, myalgia, nausea, and chills; none were serious. Seven participants experienced transient severe falls in white cell counts and/or elevations in liver transaminase levels which were considered related to malaria. Additionally, 2 participants developed ventricular extrasystoles that were attributed to unmasking of a predisposition to benign fever-induced tachyarrhythmia. In the comparative study, parasite clearance half-life after AS was significantly longer for ART-R infected participants (n = 13, 6.5 hours; 95% confidence interval [CI] 6.3-6.7 hours) compared with ART-S infected participants (n = 9, 3.2 hours; 95% CI 3.0-3.3 hours; p < 0.001). The main limitation of this study was that the ART-R and ART-S parasite strains did not share the same genetic background. CONCLUSIONS: We developed the first (to our knowledge) human model of ART-R malaria. The delayed clearance profile of ART-R parasites after AS aligns with field study observations. Although based on a relatively small sample size, results indicate that this model can be safely used to assess new drugs against ART-R P. falciparum. TRIAL REGISTRATION: The studies were registered with the Australian New Zealand Clinical Trials Registry: ACTRN12617000244303 (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372357) and ACTRN12617001394336 (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=373637).


Assuntos
Anti-Infecciosos/uso terapêutico , Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Malária Falciparum/sangue , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/metabolismo , Adolescente , Adulto , Animais , Anti-Infecciosos/efeitos adversos , Anti-Infecciosos/farmacologia , Antimaláricos/efeitos adversos , Antimaláricos/farmacologia , Artemisininas/efeitos adversos , Artemisininas/farmacologia , Artesunato/efeitos adversos , Artesunato/farmacologia , Artesunato/uso terapêutico , Austrália/epidemiologia , Feminino , Cefaleia/induzido quimicamente , Voluntários Saudáveis , Humanos , Malária Falciparum/epidemiologia , Masculino , Náusea/induzido quimicamente , Parasitos/metabolismo , Projetos Piloto , Adulto Jovem
16.
Rev Bras Parasitol Vet ; 29(2): e001820, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32609240

RESUMO

This study investigated the fauna of ectoparasitic crustaceans in Leporinus affinis from Reservoir Coaracy Nunes, in eastern Amazon (Brazil), as well as the parasite-host interactions. The mouth, gills and tegument of 50.9% of the fish examined were parasitized by Argulus chicomendesi, Ergasilus turucuyus and Excorallana berbicensis, and a total of 118 parasites were collected. The dominance was found for E. berbicensis and the higher infestation levels were caused by E. berbicensis on the body surface of the hosts, but E. turucuyus had the highest prevalence on the gills of this host. The cluster analysis revealed higher similarity in the infestations by E. berbicensis and A. chicomendesi in relation to infestation site in hosts. Host sex and relative condition factor (Kn) were not influenced by moderate parasitism, but the abundance of parasites presented negative correlation with weight and Kn of the fish. This is the first study on the parasites of L. affinis showing low species diversity, with moderate prevalence and low parasite abundance.


Assuntos
Arguloida , Caraciformes , Copépodes , Doenças dos Peixes , Parasitos , Animais , Arguloida/fisiologia , Biodiversidade , Brasil/epidemiologia , Caraciformes/parasitologia , Copépodes/fisiologia , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Doenças Parasitárias em Animais/parasitologia
17.
Rev Bras Parasitol Vet ; 29(2): e021819, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32609244

RESUMO

Comparative studies of parasites in sympatric bird species have been generally scarce. Parasitic infection/transmission can be spread in a number of ways that suggests possible direct and indirect, horizontal transmission between avian hosts. In order to determine whether two sympatric icterids from Central and Southern Chile share their parasite fauna (ecto- and endoparasites), we examined parasites of 27 Shiny Cowbirds, Molothrus bonariensis, and 28 Austral Blackbirds, Curaeus curaeus, including individuals captured in the wild and carcasses. We found that Shiny Cowbirds were infected with the chewing lice Brueelia bonariensis, Philopterus sp. 1, the feather mites Amerodectes molothrus, Proctophyllodes spp. (species 1 and 2), and the helminths Mediorhynchus papillosus, Plagiorhynchus sp., Dispharynx nasuta and Tetrameres paucispina, while Austral Blackbirds had the chewing lice Myrsidea sp., Philopterus sp. 2, the feather mites Proctophyllodes sp. 3, Amerodectes sp., and three helminths: Anonchotaenia sp., Capillaria sp. and M. papillosus. The flea Dasypsyllus (Neornipsyllus) cteniopus was found only on the Austral Blackbird. The only parasite species shared by both icterids was the acanthocephalan M. papillosus, possibly due to their feeding on the same intermediate insect hosts. With the exception of B. bonariensis and Philopterus sp. 1 found on the Shiny Cowbird, all species reported in this study represent new parasite-host associations and new records of parasite diversity in Chile.


Assuntos
Interações Hospedeiro-Parasita , Parasitos , Passeriformes , Animais , Chile , Helmintos/fisiologia , Especificidade de Hospedeiro , Ácaros/fisiologia , Parasitos/classificação , Parasitos/fisiologia , Passeriformes/parasitologia
18.
Environ Pollut ; 266(Pt 3): 115244, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32688196

RESUMO

The application of roadway deicing salts is increasing the salinity of freshwater systems. Increased salinization from salts, such as NaCl, CaCl2 and MgCl2, can have direct, negative impacts on freshwater organisms at concentrations found in nature. Yet, our understanding of how these salts can indirectly impact freshwater organisms by altering important ecological interactions, such as those between hosts and their parasites, is limited. Using a larval amphibian and infectious free-living helminth (i.e. trematode) model, we examined whether exposure to environmentally relevant concentrations of NaCl, CaCl2 and MgCl2 1) influence trematode mortality; 2) alter amphibian-trematode interactions; and 3) alter larval amphibian activity (a behavior associated with parasite avoidance). We found that exposure to CaCl2 greatly reduced trematode survival across all Cl- concentrations (230, 500, 860 and 1000 mg Cl- L-1) while NaCl and MgCl2 had no effect. When both host and parasites were exposed to the salts, exposure to NaCl, but not MgCl2 or CaCl2, increased infection. The lack of effect of CaCl2 on infection was likely driven by CaCl2 reducing trematode survival. Exposure to NaCl increased infection at 500 mg Cl- L-1, but not 230 or 860 mg Cl- L-1. Increased infection was not due to salt exposure altering tadpole behavior. Our results suggest that NaCl can negatively impact amphibian populations indirectly by increasing trematode infections in tadpole hosts.


Assuntos
Parasitos , Trematódeos , Animais , Água Doce , Larva , Salinidade , Cloreto de Sódio
19.
Emerg Microbes Infect ; 9(1): 1671-1681, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32623963

RESUMO

Infectious diseases still remain one of the biggest challenges for human health. Accurate and early detection of infectious pathogens are crucial for transmission control, clinical diagnosis, and therapy. For a traditional reason, most immunological and microbiological laboratories are equipped with instruments designated for antibody-based assays in detection of infectious pathogens or clinical diagnosis. Emerging aptamer-based technologies have pushed a shift from antibody-based to aptamer-based assays due to equal specificity, even better sensitivity, lower manufacturing cost and more flexibility in amending for chemiluminescent, electrochemical or fluorescent detection in a multifaceted and high throughput fashion in comparison of aptamer-based to antibody-based assays. The nature of aptamer-based technologies is particularly suitable for point-of-care testing in remote areas at warm or hot atmosphere, and mass screening for potential infection in pandemic of emerging infectious agents, such as SARS-CoV or SARS-CoV-2 in an epicentre or other regions. This review intends to summarize currently available aptamer-based technologies in detection of bacterial, viral, and protozoan pathogens for research and clinical application. It is anticipated that potential technologies will be further optimized and validated for clinical translation in meeting increasing demands for prompt, precise, and reliable detection of specific pathogens in various atmospheric conditions.


Assuntos
Técnicas Microbiológicas/métodos , Técnica de Seleção de Aptâmeros/métodos , Animais , Bactérias/isolamento & purificação , Humanos , Parasitos/isolamento & purificação , Vírus/isolamento & purificação
20.
Parasitol Res ; 119(9): 3053-3059, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32638102

RESUMO

Intestinal parasitic infections (IPIs) can be a severe threat to immunocompromised patients. This is particularly true for those undergoing chemotherapy and hemodialysis. The present research is aimed at identifying intestinal parasites that might be present in immunocompromised patients. In this cross-sectional study 1040 stool samples were collected from March to September 2017. Six hundred and forty-one stool samples from immunocompromised patients (279 samples from hemodialysis patients and 362 samples from chemotherapy patients) and 399 samples from the control group were collected in Guilan province, Iran. The samples were tested by direct, formalin-ether methods for protozoa and ova of intestinal parasites and Ziehl-Neelsen staining methods for coccidian parasites such as Cryptosporidium species. The overall parasitic infection rate was highest (15%) in hemodialysis patients and 11.3% in chemotherapy patients, whereas the lowest rate was observed (7.3%) in the control group. The infectivity rates were statistically significant (P = 0.008) when compared with the control group. The parasites found were Blastocystis hominis (8.9% of the cases), Entamoeba coli (1.6%), Iodamoeba butschlii (0.8%), Endolimax nana (0.6%), Chilomastix mesnili (0.5%), Strongyloides stercoralis (0.5%), and Taenia species (0.15%), whereas Giardia lamblia was detected only in the control group. There was not a correlation between prevalence of parasites with age or education levels of the infected individuals. Results of the present study suggest that periodic stool examinations in special parasitological laboratories should be included as part of routine and general medical care.


Assuntos
Infecção Hospitalar/parasitologia , Helmintíase/parasitologia , Helmintos/isolamento & purificação , Intestinos/parasitologia , Neoplasias/parasitologia , Parasitos/isolamento & purificação , Diálise Renal/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Estudos Transversais , Fezes/parasitologia , Feminino , Helmintíase/imunologia , Helmintos/classificação , Humanos , Hospedeiro Imunocomprometido , Enteropatias Parasitárias/parasitologia , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Neoplasias/imunologia , Parasitos/classificação , Parasitos/genética , Prevalência , Adulto Jovem
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