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1.
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
2.
Parasitol Res ; 119(10): 3221-3231, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32671541

RESUMO

Members of the genus Lueheia Travassos, 1919, are endoparasites of birds, particularly passerines, throughout the Americas. Adults of Lueheia sp., (Plagiorhynchidae Golvan, 1960; Porrorchinae Golvan, 1956) were recovered from the intestine of the American robin (Turdus migratorius phillipsi Bangs) in Mexico City, and two other species of acanthocephalans identified as Porrorchis nickoli, (Plagiorhynchidae: Porrorchinae) Salgado-Maldonado and Cruz-Reyes, 2002 and Centrorhynchus microcephalus (Bravo-Hollis, 1947) Golvan, 1956 (Centrorhynchidae Van Cleave, 1916), were recovered from the Virginia opossum (Didelphis virginiana Allen) and groove-billed ani (Crotophaga sulcirostris Swainson), respectively in southeastern Mexico. Specimens of three species were sequenced at two molecular markers, the small subunit (SSU) and large subunit (LSU) of the nuclear rDNA and compared with other sequences available in GenBank. Maximum likelihood and Bayesian inference analyses of the combined (LSU + SSU) dataset and each individual dataset revealed that the specimens of Lueheia sp. formed an independent lineage, which is recognized herein as a new species, Lueheia aztecae n. sp., representing the fifth species of the genus in the Americas, and the second in the Nearctic region. The new species can be morphologically distinguished from the other five species in the genus by having a cylindrical proboscis, armed with 24-26 longitudinal rows with 9-10 hooks each. Phylogenetic inference performed with the combined dataset consisting of two genes (LSU + SSU) revealed that Lueheia aztecae n. sp. and P. nickoli belonging to subfamily Porrorchinae, formed two independent lineages, indicating that the subfamily is paraphyletic. Porrorchis nickoli and C. microcephalus formed a clade with other species of the genus Centrorhynchus, suggesting that P. nickoli should be transferred to genus Centrorhynchus, to form C. nickoli n. comb. In addition, we briefly discuss the ecological associations between the members of the families Plagiorhynchidae and Centrorhynchidae.


Assuntos
Acantocéfalos/anatomia & histologia , Acantocéfalos/classificação , Helmintíase Animal/parasitologia , Aves Canoras/parasitologia , Acantocéfalos/genética , Animais , Sequência de Bases , Teorema de Bayes , DNA Ribossômico/genética , Marcadores Genéticos/genética , Intestinos/parasitologia , México , Filogenia
3.
J Parasitol ; 106(2): 291-294, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32296848

RESUMO

The wood thrush, Hylocichla mustelina, is a North American passerine bird closely related to other thrushes and is widely distributed across North America. Nothing is known of the coccidian parasites of this bird. Feces from a single H. mustelina found dead in McCurtain County, Oklahoma were collected and examined for coccidia; it was found to be passing a new species of Isospora. Oocysts of Isospora gmelini n. sp. are subspheroidal to ellipsoidal with a smooth bilayered wall, measure (length [L] × width [W]) 19.5 × 16.5 µm, and have a L/W ratio of 1.2; a micropyle and oocyst residuum were absent but polar granule(s) are present. Sporocysts are ellipsoidal to elongate and measure 13.4 × 8.9 µm, L/W 1.5; a buttonlike Stieda body is present, but sub-Stieda and para-Stieda bodies are absent. The sporocyst residuum is composed of a compact spheroid with a dense, irregular mass of finer granules lying between and dispersed among the sporozoites. Although several isosporans have been reported from other turdid birds, mainly from Brazil and Costa Rica, this is the initial coccidian reported from H. mustelina and only the second known from the Turdidae in the mainland of the United States.


Assuntos
Doenças das Aves/parasitologia , Isospora/isolamento & purificação , Isosporíase/veterinária , Aves Canoras/parasitologia , Animais , Fezes/parasitologia , Isospora/classificação , Isospora/ultraestrutura , Isosporíase/parasitologia , Masculino , Microscopia de Interferência/veterinária , Oklahoma , Oocistos/ultraestrutura
4.
Malar J ; 19(1): 69, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32050970

RESUMO

BACKGROUND: Passerine birds are frequently infected with diverse haemosporidian parasites. While infections are traditionally considered benign in wild birds, recent studies demonstrated mortalities of passerine species due to exo-erythrocytic development of the parasites, which can damage organs in affected hosts. However, exo-erythrocytic development remains insufficiently investigated for most haemosporidian species and thus little is known about the virulence of tissue stages in wild passerine birds. The aim of the present study was to investigate natural haemosporidian infections in deceased Eurasian blackbirds (Turdus merula) and song thrushes (Turdus philomelos) and to determine parasite burden and associated histological effects. METHODS: For molecular analysis, blood and tissue samples from 306 thrushes were screened for Plasmodium, Haemoproteus and Leucocytozoon parasites by nested PCR. For the detection of parasite stages in organ samples, tissue sections were subjected to chromogenic in situ hybridization (CISH) using genus- and species-specific probes targeting the rRNAs of parasites. Exo-erythrocytic parasite burden was semi-quantitatively assessed and histological lesions were evaluated in haematoxylin-eosin-stained sections. RESULTS: By PCR, 179 of 277 Eurasian blackbirds and 15 of 29 song thrushes were positive for haemosporidians. Parasites of all three genera were detected, with Plasmodium matutinum LINN1 and Plasmodium vaughani SYAT05 showing the highest prevalence. CISH revealed significant differences in exo-erythrocytic parasite burden between lineages in Eurasian blackbirds, with P. matutinum LINN1 frequently causing high exo-erythrocytic parasite burdens in various organs that were associated with histological alterations. Song thrushes infected with P. matutinum LINN1 and birds infected with other haemosporidian lineages showed mostly low exo-erythrocytic parasite burdens. Two Eurasian blackbirds infected with Leucocytozoon sp. TUMER01 showed megalomeronts in various organs that were associated with inflammatory reactions and necroses. CONCLUSION: This study suggests that P. matutinum LINN1, a common lineage among native thrushes, regularly causes high exo-erythrocytic parasite burdens in Eurasian blackbirds, which may result in disease and mortalities, indicating its high pathogenic potential. The findings further illustrate that the same parasite lineage may show different levels of virulence in related bird species which should be considered when assessing the pathogenicity of haemosporidian parasite species. Finally, the study provides evidence of virulent Leucocytozoon sp. TUMER01 infections in two Eurasian blackbirds caused by megalomeront formation.


Assuntos
Doenças das Aves/parasitologia , Haemosporida/fisiologia , Infecções Protozoárias em Animais/parasitologia , Aves Canoras/parasitologia , Animais , Animais Selvagens , Áustria , Bolsa de Fabricius/parasitologia , DNA de Protozoário/genética , DNA de Protozoário/isolamento & purificação , Haemosporida/genética , Haemosporida/isolamento & purificação , Haemosporida/patogenicidade , Coração/parasitologia , Hibridização In Situ/métodos , Hibridização In Situ/veterinária , Rim/parasitologia , Plasmodium/classificação , Plasmodium/genética , Plasmodium/isolamento & purificação , Reação em Cadeia da Polimerase/veterinária , Especificidade da Espécie , Virulência
5.
Mol Ecol Resour ; 20(1): 14-28, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31507097

RESUMO

Metatranscriptomics is a powerful method for studying the composition and function of complex microbial communities. The application of metatranscriptomics to multispecies parasite infections is of particular interest, as research on parasite evolution and diversification has been hampered by technical challenges to genome-scale DNA sequencing. In particular, blood parasites of vertebrates are abundant and diverse although they often occur at low infection intensities and exist as multispecies infections, rendering the isolation of genomic sequence data challenging. Here, we use birds and their diverse haemosporidian parasites to illustrate the potential for metatranscriptome sequencing to generate large quantities of genome-wide sequence data from multiple blood parasite species simultaneously. We used RNA-sequencing of 24 blood samples from songbirds in North America to show that metatranscriptomes can yield large proportions of haemosporidian protein-coding gene repertoires even when infections are of low intensity (<0.1% red blood cells infected) and consist of multiple parasite taxa. By bioinformatically separating host and parasite transcripts and assigning them to the haemosporidian genus of origin, we found that transcriptomes detected ~23% more total parasite infections across all samples than were identified using microscopy and DNA barcoding. For single-species infections, we obtained data for >1,300 loci from samples with as low as 0.03% parasitaemia, with the number of loci increasing with infection intensity. In total, we provide data for 1,502 single-copy orthologous loci from a phylogenetically diverse set of 33 haemosporidian mitochondrial lineages. The metatranscriptomic approach described here has the potential to accelerate ecological and evolutionary research on haemosporidians and other diverse parasites.


Assuntos
Doenças das Aves/parasitologia , Sangue/parasitologia , Genômica/métodos , Haemosporida/isolamento & purificação , Infecções Protozoárias em Animais/parasitologia , Animais , Doenças das Aves/sangue , Haemosporida/classificação , Haemosporida/genética , Filogenia , Infecções Protozoárias em Animais/sangue , Aves Canoras/sangue , Aves Canoras/parasitologia , Transcriptoma
6.
Parasitol Res ; 119(2): 611-621, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31754855

RESUMO

A new Caryospora-like isolate is described from a magpie-lark (Grallina cyanoleuca) in Western Australia. Sporulated oocysts of the Caryospora-like isolate (n = 35) are subspherical with a shape index of 1.13 ((21.5 (19.7-23.6) × 19.0 (18.1-19.8) µm). The bilayered oocyst wall is smooth. Micropyle, polar granule and oocyst residuum are absent. The sporocyst is ellipsoidal, 18.9 (17.2-20.8) × 12.3 (11.9-12.8) µm, with a shape index (length/width) of 1.54. The sporocyst wall is bilayered. Stieda and substieda bodies are present, the Stieda body is small and flattened and the substieda is trapezoidal. Sporocyst with eight sporozoites arranged head to tail. The sporozoites are vermiform, 18.9 (17.2-20.8) × 12.3 (11.9-12.8) µm and have striations at the anterior end. Each sporozoite has both anterior and posterior refractile bodies. A sporocyst residuum is present. Molecular characterization of the isolated Caryospora-like oocysts was conducted at the 18S ribosomal RNA and the mitochondrial cytochrome oxidase (COI) loci. At the 18S rRNA locus, the Caryospora-like isolate exhibited 88.8% to 96.5% similarity with other Caryospora spp. from different hosts. At the COI locus, it showed 91.5% similarity to Caryospora cf. bigenetica JB-2013 (KF859856) from the rattlesnake, Sistrurus catenatus.


Assuntos
Doenças das Aves/parasitologia , Eimeriidae/classificação , Aves Canoras/parasitologia , Animais , DNA de Protozoário , Eimeriidae/citologia , Eimeriidae/isolamento & purificação , Feminino , Masculino , Oocistos/classificação , Filogenia , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , Esporozoítos , Austrália Ocidental
7.
Parasit Vectors ; 12(1): 516, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31685020

RESUMO

BACKGROUND: Haemoproteus parasites (Haemosporida, Haemoproteidae) are cosmopolitan in birds and recent molecular studies indicate enormous genetic diversity of these pathogens, which cause diseases in non-adapted avian hosts. However, life-cycles remain unknown for the majority of Haemoproteus species. Information on their exoerythrocytic development is particularly fragmental and controversial. This study aimed to gain new knowledge on life-cycle of the widespread blood parasite Haemoproteus majoris. METHODS: Turdus pilaris and Parus major naturally infected with lineages hPHYBOR04 and hPARUS1 of H. majoris, respectively, were wild-caught and the parasites were identified using microscopic examination of gametocytes and PCR-based testing. Bayesian phylogeny was used to determine relationships between H. majoris lineages. Exoerythrocytic stages (megalomeronts) were reported using histological examination and laser microdissection was applied to isolate single megalomeronts for genetic analysis. Culicoides impunctatus biting midges were experimentally exposed in order to follow sporogonic development of the lineage hPHYBOR04. RESULTS: Gametocytes of the lineage hPHYBOR04 are indistinguishable from those of the widespread lineage hPARUS1 of H. majoris, indicating that both of these lineages belong to the H. majoris group. Phylogenetic analysis supported this conclusion. Sporogony of the lineage hPHYBOR04 was completed in C. impunctatus biting midges. Morphologically similar megalomeronts were reported in internal organs of both avian hosts. These were big roundish bodies (up to 360 µm in diameter) surrounded by a thick capsule-like wall and containing irregularly shaped cytomeres, in which numerous merozoites developed. DNA sequences obtained from single isolated megalomeronts confirmed the identification of H. majoris. CONCLUSIONS: Phylogenetic analysis identified a group of closely related H. majoris lineages, two of which are characterized not only by morphologically identical blood stages, but also complete sporogonic development in C. impunctatus and development of morphologically similar megalomeronts. It is probable that other lineages belonging to the same group would bear the same characters and phylogenies based on partial cytb gene could be used to predict life-cycle features in avian haemoproteids including vector identity and patterns of exoerythrocytic merogony. This study reports morphologically unique megalomeronts in naturally infected birds and calls for research on exoerythrocytic development of haemoproteids to better understand pathologies caused in avian hosts.


Assuntos
Doenças das Aves/parasitologia , Haemosporida/crescimento & desenvolvimento , Estágios do Ciclo de Vida , Passeriformes/parasitologia , Infecções Protozoárias em Animais/parasitologia , Aves Canoras/parasitologia , Animais , Teorema de Bayes , Aves , Ceratopogonidae/parasitologia , Haemosporida/classificação , Haemosporida/genética , Filogenia
8.
Korean J Parasitol ; 57(5): 461-467, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31715686

RESUMO

Avian trematodes, Urogonimus turdi (Digenea: Leucochloridiidae), were collected from the intestine of wild birds, Zoothera aurea, 2013-2017 in the Daejeon Metropolitan City, Korea. The body was ellipsoidal, attenuated and/or round ends, 1,987-2,120 long and 819-831 µm wide. The oral sucker was subterminal, rounded anteriorly, and 308- 425×351-432 µm in size; the prepharynx and esophagus were almost lacking; pharynx was well-developed, 142- 179×78-170 µm in size; intestine narrow, bifurcating just after pharynx, ascending to the oral sucker before looping posteriorly and terminating near the posterior end; ventral sucker larger, in almost median, 536-673×447-605 µm and approximately 1.5 times larger than oral sucker. A phylogenetic tree constructed with 18S ribosomal RNA showed inter- and intraspecific relationships. Based on these morphological and molecular findings, we report here a U. turdi from White's thrushes in Korea.


Assuntos
Doenças das Aves/parasitologia , Aves Canoras/parasitologia , Trematódeos/isolamento & purificação , Infecções por Trematódeos/veterinária , Animais , Tamanho Corporal , Feminino , Masculino , Filogenia , República da Coreia , Trematódeos/anatomia & histologia , Trematódeos/classificação , Trematódeos/genética , Infecções por Trematódeos/parasitologia
9.
Int J Parasitol ; 49(13-14): 1005-1014, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31734336

RESUMO

Mechanisms of on-host habitat selection of parasites are important to the understanding of host-parasite interactions and evolution. To this end, it is important to separate the factors driving parasite micro-habitat selection from those resulting from host anti-parasite behaviour. We experimentally investigated whether tick infestation patterns on songbirds are the result of an active choice by the ticks themselves, or the outcome of songbird grooming behaviour. Attachment patterns of three ixodid tick species with different ecologies and host specificities were studied on avian hosts. Ixodes arboricola, Ixodes ricinus and Ixodes frontalis were put on the head, belly and back of adult great tits (Parus major) and adult domestic canaries (Serinus canaria domestica) which were either restricted or not in their grooming capabilities. Without exception, ticks were eventually found on a bird's head. When we gave ticks full opportunities to attach on other body parts - in the absence of host grooming - they showed lower attachment success. Moreover, ticks moved from these other body parts to the host's head when given the opportunity. This study provides evidence that the commonly observed pattern of ticks feeding on songbirds' heads is the result of an adaptive behavioural strategy. Experimental data on a novel host species, the domestic canary, and a consistent number of published field observations, strongly support this hypothesis. We address some proximate and ultimate causes that may explain parasite preference for this body part in songbirds. The link found between parasite micro-habitat preference and host anti-parasite behaviour provides further insight into the mechanisms driving ectoparasite aggregation, which is important for the population dynamics of hosts, ectoparasites and the micro-pathogens for which they are vectors.


Assuntos
Ecossistema , Comportamento Alimentar , Interações Hospedeiro-Parasita , Ixodes/crescimento & desenvolvimento , Aves Canoras/parasitologia , Animais , Cabeça/parasitologia
10.
Sci Rep ; 9(1): 17002, 2019 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-31740690

RESUMO

Ecdysteroids (arthropod molting hormones) play an important role in the development and sexual maturation of arthropods, and they have been shown to have anabolic and "energizing" effect in higher vertebrates. The aim of this study was to assess ecdysteroid diversity, levels according to bird species and months, as well as to observe the molting status of hard ticks (Acari: Ixodidae) infesting the birds. Therefore, blood samples and ticks were collected from 245 birds (244 songbirds and a quail). Mass spectrometric analyses showed that 15 ecdysteroids were regularly present in the blood samples. Molting hormones biologically most active in insects (including 20-hydroxyecdysone [20E], 2deoxy-20E, ajugasterone C and dacryhainansterone) reached different levels of concentration according to bird species and season. Similarly to ecdysteroids, the seasonal presence of affected, apolytic ticks peaked in July and August. In conclusion, this study demonstrates the presence of a broad range and high concentrations of ecdysteroids in the blood stream of wild-living passerine birds. These biologically active, anabolic compounds might possibly contribute to the known high metabolic rate of songbirds.


Assuntos
Animais Selvagens/sangue , Ecdisona/sangue , Ecdisteroides/sangue , Aves Canoras/sangue , Animais , Animais Selvagens/parasitologia , Artrópodes/crescimento & desenvolvimento , Artrópodes/metabolismo , Ecdisona/química , Ecdisteroides/química , Ecdisterona/análogos & derivados , Ecdisterona/sangue , Ecdisterona/química , Ecdisterona/metabolismo , Interações Hospedeiro-Parasita , Ixodidae/crescimento & desenvolvimento , Ixodidae/fisiologia , Estrutura Molecular , Muda , Estações do Ano , Aves Canoras/classificação , Aves Canoras/parasitologia , Especificidade da Espécie
11.
Sci Rep ; 9(1): 16652, 2019 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-31723147

RESUMO

In eastern North America, including Canada, Lyme disease is caused by Borrelia burgdorferi sensu stricto and transmitted to humans by the blacklegged tick, Ixodes scapularis. The last decade has seen a growing incidence of Lyme disease in Canada, following the northward range expansion of I. scapularis tick populations from endemic areas in eastern United States. This may be attributable to movement of the many hosts that they parasitize, including songbirds, deer and small mammals. In this study, we wanted to test the effect of spatial, temporal and ecological variables, on blacklegged tick density and infection rates, near the northern limit of their distribution in Ontario and Quebec, Canada. We found an effect of both proportion of forested areas and distance to roads, on density of I. scapularis ticks and prevalence of infection by B. burgdorferi. We also found an effect of both sampling year and ordinal sampling data on prevalence of infection by B. burgdorferi. In six adjacent sites showing evidence of reproducing I. scapularis populations, we found that forest composition and structure influenced density of I. scapularis ticks. Our results suggest that blacklegged tick density and infection rate in Canada may be influenced by a variety of factors.


Assuntos
Vetores Aracnídeos/microbiologia , Doenças das Aves/parasitologia , Borrelia burgdorferi/isolamento & purificação , Ixodes/microbiologia , Doença de Lyme/transmissão , Infestações por Carrapato/veterinária , Animais , Doenças das Aves/epidemiologia , Cervos/parasitologia , Ixodes/classificação , Doença de Lyme/epidemiologia , Densidade Demográfica , Prevalência , Quebeque/epidemiologia , Aves Canoras/parasitologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia
12.
Rev Bras Parasitol Vet ; 28(3): 432-442, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31531671

RESUMO

A total of thirty Austral thrushes Turdus falcklandii Quoy & Gaimard, 1824 (Turdidae) carcasses were brought to the Departamento de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad de Concepción, to be examined for ecto- and endoparasites. Ectoparasites were found on 20% (6/30) of the thrushes and belonged to species Brueelia magellanica Cichino, 1986 (Phthiraptera), Menacanthus eurysternus Burmeister, 1838 (Phthiraptera) and Tyrannidectes falcklandicus Mironov & González-Acuña, 2011 (Acari). Endoparasites were isolated from 26.6% (8/30) of the birds and identified as Lueheia inscripta Westrumb, 1821 (Acanthocephala), Plagiorhynchus cylindraceus Goeze, 1782 (Acanthocephala), Wardium sp. sensu Mayhew, 1925 (Cestoda), Dilepis undula (Cestoda) Schrank, 1788, and Zonorchis sp. (sensu Travassos, 1944) (Trematoda). To our knowledge, all endoparasites collected in this study are new records in T. falcklandii and expand their distributional range to Chile.


Assuntos
Doenças das Aves/diagnóstico , Ectoparasitoses/veterinária , Enteropatias Parasitárias/veterinária , Aves Canoras/parasitologia , Animais , Doenças das Aves/parasitologia , Chile , Ectoparasitoses/diagnóstico , Ectoparasitoses/parasitologia , Enteropatias Parasitárias/diagnóstico , Enteropatias Parasitárias/parasitologia
13.
Rev. bras. parasitol. vet ; 28(3): 432-442, July-Sept. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1042531

RESUMO

Abstract A total of thirty Austral thrushes Turdus falcklandii Quoy & Gaimard, 1824 (Turdidae) carcasses were brought to the Departamento de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad de Concepción, to be examined for ecto- and endoparasites. Ectoparasites were found on 20% (6/30) of the thrushes and belonged to species Brueelia magellanica Cichino, 1986 (Phthiraptera), Menacanthus eurysternus Burmeister, 1838 (Phthiraptera) and Tyrannidectes falcklandicus Mironov & González-Acuña, 2011 (Acari). Endoparasites were isolated from 26.6% (8/30) of the birds and identified as Lueheia inscripta Westrumb, 1821 (Acanthocephala), Plagiorhynchus cylindraceus Goeze, 1782 (Acanthocephala), Wardium sp. sensu Mayhew, 1925 (Cestoda), Dilepis undula (Cestoda) Schrank, 1788, and Zonorchis sp. (sensu Travassos, 1944) (Trematoda). To our knowledge, all endoparasites collected in this study are new records in T. falcklandii and expand their distributional range to Chile.


Resumo Um total de trinta carcaças do tordo-austral Turdus falcklandii Quoy & Gaimard, 1824 (Turdidae) foi encaminhado ao Departamento de Ciência Animal, Facultad de Ciencias Veterinarias, Universidad de Concepción, para ser examinado quanto a presença de parasitas externos e internos. Parasitas externos foram encontrados em 20% (6/30) dos tordos inspecionados e identificados como Brueelia magellanica Cichino, 1986 (Phthiraptera), Menacanthus eurysternus Burmeister, 1838 (Phthiraptera), e Tyrannidectes falcklandicus Mironov & González-Acuña, 2011 (Acari). Parasitas internos foram identificados em 26,6% (8/30) dos espécimes examinados como Lueheia inscripta Westrumb, 1821 (Acanthocephala), Plagiorhynchus cylindraceus Goeze, 1782 (Acanthocephala), Wardium sp. sensu Mayhew, 1925 (Cestoda), Dilepis undula sensu Schrank, 1788 (Cestoda) e Zonorchis sp. (sensu Travassos, 1944) (Trematoda). Tanto quanto é do nosso conhecimento, todos os parasitas internos coletados neste estudo pertencem a novos registros em T. falcklandii e com expansão de sua distribuição para o Chile.


Assuntos
Animais , Doenças das Aves/diagnóstico , Aves Canoras/parasitologia , Ectoparasitoses/veterinária , Enteropatias Parasitárias/veterinária , Doenças das Aves/patologia , Chile , Ectoparasitoses/diagnóstico , Ectoparasitoses/parasitologia , Enteropatias Parasitárias/diagnóstico , Enteropatias Parasitárias/parasitologia
14.
Parasit Vectors ; 12(1): 230, 2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31088533

RESUMO

BACKGROUND: Peritoneal larval cestodiasis induced by Mesocestoides Vaillant, 1863 (Cyclophyllidea: Mesocestoididae) is a common cause of severe infections in domestic dogs and cats, reported also from other mammals and less frequently from birds. However, there is a limited knowledge on the taxonomy of causative agents of this disease. RESULTS: In the present study, we investigated a massive, likely lethal, infection of a song thrush Turdus philomelos (Passeriformes: Turdidae) by Mesocestoides sp. tetrathyridia. We performed combined morphological and phylogenetic analysis of the tetrathyridia and compared them with the materials obtained previously from other birds and mammals. The metrical data fitted within the wide range reported by previous authors but confirmed the limited value of morphological data for species identification of tetrathyridia of Mesocestoides spp. The molecular analyses suggested that the isolates represented an unidentified Mesocestoides sp. that was previously repeatedly isolated and sequenced in larval and adult forms from domestic dogs and cats in Europe, the Middle East and North Africa. In contrast to the present study, which found encysted tetrathyridia, four of the five previous studies that identified the same species described infections by acephalic metacestodes only. CONCLUSIONS: The tetrathyridia of the examined Mesocestoides sp. are described in the present study for the first time. However, the possible match with the species that were previously reported to infect birds remains uncertain. The phylogenetic analyses also suggested the rejection of two cases that were previously identified as Mesocestoides corti as they were likely caused by the same species as in the presently reported infection case. The newly provided DNA sequences should allow the assignment to species in the future, when adults of the genus Mesocestoides are more thoroughly sequenced.


Assuntos
Cisticercose/veterinária , Mamíferos/parasitologia , Mesocestoides/genética , Animais de Estimação/parasitologia , Aves Canoras/parasitologia , Animais , Sequência de Bases , Doenças do Gato/parasitologia , Doenças do Gato/transmissão , Gatos , Cisticercose/transmissão , Doenças do Cão/parasitologia , Doenças do Cão/transmissão , Cães , Evolução Fatal , Feminino , Mesocestoides/patogenicidade , Filogenia
15.
Philos Trans R Soc Lond B Biol Sci ; 374(1769): 20180195, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30967077

RESUMO

The optimal acceptance threshold hypothesis provides a general predictive framework for testing behavioural responses to discrimination challenges. Decision-makers should respond to a stimulus when the perceived difference between that stimulus and a comparison template surpasses an acceptance threshold. We tested how individual components of a relevant recognition cue (experimental eggs) contributed to behavioural responses of chalk-browed mockingbirds, Mimus saturninus, a frequent host of the parasitic shiny cowbird, Molothrus bonariensis. To do this, we recorded responses to eggs that varied with respect to two components: colour, ranging from bluer to browner than the hosts' own eggs, and spotting, either spotted like their own or unspotted. Although tests of this hypothesis typically assume that decisions are based on perceived colour dissimilarity between own and foreign eggs, we found that decisions were biased toward rejecting browner eggs. However, as predicted, hosts tolerated spotted eggs more than unspotted eggs, irrespective of colour. These results uncover how a single component of a multicomponent cue can shift a host's discrimination threshold and illustrate how the optimal acceptance threshold hypothesis can be used as a framework to quantify the direction and amount of the shift (in avian perceptual units) of the response curve across relevant phenotypic ranges. This article is part of the theme issue 'The coevolutionary biology of brood parasitism: from mechanism to pattern'.


Assuntos
Percepção de Cores , Sinais (Psicologia) , Comportamento de Nidação , Aves Canoras/fisiologia , Aves Canoras/parasitologia , Animais , Cor , Tomada de Decisões , Óvulo , Reconhecimento Psicológico
16.
Philos Trans R Soc Lond B Biol Sci ; 374(1769): 20180197, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30967078

RESUMO

Despite a recent explosion of research on pattern recognition, in both neuroscience and computer vision, we lack a basic understanding of how most animals perceive and respond to patterns in the wild. Avian brood parasites and their hosts provide an ideal study system for investigating the mechanisms of pattern recognition. The cuckoo finch, Anomalospiza imberbis, and its host the tawny-flanked prinia, Prinia subflava, lay highly polymorphic eggs with a great deal of variation in colour and patterning, with the cuckoo finch capable of close egg mimicry. Behavioural experiments in Zambia have previously shown that prinias use colour and multiple 'low-level' (occurring in early stages of visual processing) pattern attributes, derived from spatial frequency analysis, when rejecting foreign eggs. Here, we explore the extent to which host birds might also use 'higher-level' pattern attributes, derived from a feature detection algorithm, to make rejection decisions. Using a SIFT-based pattern recognition algorithm, NaturePatternMatch, we show that hosts are more likely to reject a foreign egg if its higher-level pattern features-which capture information about the shape and orientation of markings-differ from those of the host eggs. A revised statistical model explains about 37% variance in egg rejection behaviour, and differences in colour, low-level and higher-level pattern features all predict rejection, accounting for 42, 44 and 14% of the explained variance, respectively. Thus, higher-level pattern features provide a small but measurable improvement to the original model and may be especially useful when colour and low-level pattern features provide hosts with little information. Understanding the relative importance of low- and higher-level pattern features is a valuable goal for future work on animal coloration, especially in the contexts of mimicry, camouflage and individual recognition. This article is part of the theme issue 'The coevolutionary biology of brood parasitism: from mechanism to pattern'.


Assuntos
Interações Hospedeiro-Parasita , Comportamento de Nidação , Reconhecimento Visual de Modelos , Aves Canoras/fisiologia , Aves Canoras/parasitologia , Animais , Evolução Biológica , Feminino , Tentilhões/parasitologia , Tentilhões/fisiologia , Reconhecimento Psicológico , Zâmbia
17.
Proc Biol Sci ; 286(1897): 20190049, 2019 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-30963843

RESUMO

When confronted with a parasite or pathogen, hosts can defend themselves by resisting or tolerating the attack. While resistance can be diminished when resources are limited, it is unclear how robust tolerance is to changes in environmental conditions. Here, we investigate the sensitivity of tolerance in a single host population living in a highly variable environment. We manipulated the abundance of an invasive parasitic fly, Philornis downsi, in nests of Galápagos mockingbirds ( Mimus parvulus) over four field seasons and measured host fitness in response to parasitism. Mockingbird tolerance to P. downsi varied significantly among years and decreased when rainfall was limited. Video observations indicate that parental provisioning of nestlings appears key to tolerance: in drought years, mockingbirds likely do not have sufficient resources to compensate for the effects of P. downsi. These results indicate that host tolerance is a labile trait and suggest that environmental variation plays a major role in mediating the consequences of host-parasite interactions.


Assuntos
Interações Hospedeiro-Parasita , Espécies Introduzidas , Muscidae/fisiologia , Aves Canoras/fisiologia , Aves Canoras/parasitologia , Animais , Meio Ambiente , Aptidão Genética , Chuva , Estações do Ano , Aves Canoras/genética
18.
Int J Parasitol ; 49(6): 437-448, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30910465

RESUMO

Haemosporidian parasites of birds are ubiquitous in terrestrial ecosystems, but their coevolutionary dynamics remain poorly understood. If species turnover in parasites occurs at a finer scale than turnover in hosts, widespread hosts would encounter diverse parasites, potentially diversifying as a result. Previous studies have shown that some wide-ranging hosts encounter varied haemosporidian communities throughout their range, and vice-versa. More surveys are needed to elucidate mechanisms that underpin spatial patterns of diversity in this complex multi-host multi-parasite system. We sought to understand how and why a community of avian haemosporidian parasites varies in abundance and composition across elevational transects in eight sky islands in southwestern North America. We tested whether bird community composition, environment, or geographic distance explain haemosporidian parasite species turnover in a widespread host that harbors a diverse haemosporidian community, the Audubon's Warbler (Setophaga auduboni). We tested predictors of infection using generalized linear models, and predictors of bird and parasite community dissimilarity using generalized dissimilarity modeling. Predictors of infection differed by parasite genus: Parahaemoproteus was predicted by elevation and climate, Leucocytozoon varied idiosyncratically among mountains, and Plasmodium was unpredictable, but rare. Parasite turnover was nearly three-fold higher than bird turnover and was predicted by elevation, climate, and bird community composition, but not geographic distance. Haemosporidian communities vary strikingly at fine spatial scales (hundreds of kilometers), across which the bird community varies only subtly. The finer scale of turnover among parasites implies that their ranges may be smaller than those of their hosts. Avian host species should encounter different parasite species in different parts of their ranges, resulting in spatially varying selection on host immune systems. The fact that parasite turnover was predicted by bird turnover, even when considering environmental characteristics, implies that host species or their phylogenetic history plays a role in determining which parasite species will be present in a community.


Assuntos
Doenças das Aves/parasitologia , Haemosporida/fisiologia , Infecções Protozoárias em Animais/parasitologia , Aves Canoras/parasitologia , Altitude , Animais , Distribuição Binomial , Biodiversidade , Intervalos de Confiança , DNA de Protozoário/isolamento & purificação , Clima Desértico , Florestas , Haemosporida/classificação , Haplótipos , Funções Verossimilhança , Modelos Lineares , Dinâmica não Linear , Filogenia , Infecções Protozoárias em Animais/epidemiologia , Análise de Regressão , Sudoeste dos Estados Unidos , Análise Espacial
19.
Ticks Tick Borne Dis ; 10(3): 546-552, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30709658

RESUMO

Presently, it is uncertain to what extent seasonal migrating birds contribute to the introduction of ticks and tick-associated pathogens in Denmark. To quantify this phenomenon, we captured birds during the spring and autumn migration at three field sites in Denmark and screened them for ticks. Bird-derived ticks were identified to tick species and screened for 37 tick-borne pathogens using real-time PCR. Overall, 807 birds, representing 44 bird species, were captured and examined for ticks during the spring (292 birds) and autumn migrations (515 birds). 10.7% of the birds harboured a total of 179 Ixodes ricinus ticks (38 ticks in spring and 141 in the autumn) with a mean infestation intensity of 2.1 ticks per bird. The European robin (Erithacus rubecula), the common blackbird (Turdus merula), and the common redstart (Phoenicurus phoenicurus) had the highest infestation intensities. 60.9% of the ticks were PCR-positive for at least one tick-borne pathogen. Borrelia DNA was found in 36.9% of the ticks. The Borrelia species detected were B. spielmanii (15.1%), B. valaisiana (13.4%), B. garinii (12.3%), B. burgdorferi s.s. (2.2%), B. miyamotoi (1.1%), and B. afzelii (0.6%). In addition, 10.6% and 1.7% of the samples were PCR-positive for spotted fever group rickettsiae and Candidatus Neoehrlichia mikurensis. All of the tick-borne pathogens that we found in the present study are known to occur in Danish forest populations of I. ricinus. Our study indicates that migrating birds can transport ticks and their pathogens from neighboring countries to Denmark including sites in Denmark without a sustainable tick population. Thus, a tick-borne pathogen affecting human or animal health emerging at one location in Europe can rapidly be introduced to other countries by migrating birds. These movements are beyond national veterinary control. The current globalization, climatic and environmental changes affect the potential for introduction and establishment of ticks and tick-borne pathogens in Northern Europe. It is therefore important to quantify the risk for rapid spread and long distance exchange of tick-borne pathogens in Europe.


Assuntos
Bactérias/isolamento & purificação , Doenças das Aves/diagnóstico , Aves/parasitologia , Infestações por Carrapato/veterinária , Doenças Transmitidas por Carrapatos/veterinária , Migração Animal , Animais , Bactérias/genética , Doenças das Aves/microbiologia , Borrelia/genética , Borrelia/isolamento & purificação , Dinamarca/epidemiologia , Europa (Continente) , Ixodes , Passeriformes/parasitologia , Reação em Cadeia da Polimerase em Tempo Real , Rickettsia/genética , Rickettsia/isolamento & purificação , Aves Canoras/parasitologia , Infestações por Carrapato/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/microbiologia
20.
Vector Borne Zoonotic Dis ; 19(6): 450-452, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30615582

RESUMO

Passerine birds are significantly involved in the dissemination of Borreliella spp. bacteria (formerly Borrelia burgdorferi sensu lato complex), the causative agent of most common and important tick-spread disease Lyme borreliosis. Among several dozen investigated passerine bird species, thrushes (Turdidae) have been reported as a relatively good pathogen reservoirs and disseminators. The principal aim of the study was to identify the differences in Borreliella spp. reservoir competence between two widespread and showing similar behavior thrush species. A total of 157 Ixodes ricinus ticks (19 larvae, 138 nymphs) were collected from 26 blackbirds (Turdus merula) and 20 song thrushes (Turdus philomelos) living in the same forest habitat (northeastern Poland). All, at least partially engorged ectoparasites, were tested for the presence of Borreliella spp. DNA using the nested-PCR technique. No significant difference of tick prevalence was found, with 88.5% blackbirds and 70% of song thrushes infested. Screening for Borreliella spp. in ticks revealed that both tick infection prevalence (49.2% vs. 18.9%) and mean number of infected individuals engorging on birds (2.27 vs. 0.35) were higher in blackbirds. Both the investigated thrush species presumably could participate in the pathogen circulation, although with different efficiencies. The greater reservoir competence of blackbirds suggests the differentiated dynamics of host-pathogen interactions among selected species, and consequently their potentially disparate role in the ecology of Lyme borreliosis.


Assuntos
Doenças das Aves/microbiologia , Grupo Borrelia Burgdorferi/isolamento & purificação , Reservatórios de Doenças/veterinária , Doença de Lyme/veterinária , Aves Canoras/parasitologia , Animais , Vetores Aracnídeos/microbiologia , Infecções por Borrelia , Reservatórios de Doenças/microbiologia , Ixodes/microbiologia , Larva/microbiologia , Doença de Lyme/microbiologia , Polônia/epidemiologia , Aves Canoras/microbiologia , Especificidade da Espécie , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterinária
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