| 1. |
- Marzal, Alfonso, et al.
(författare)
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Diversity, Loss, and Gain of Malaria Parasites in a Globally Invasive Bird.
- 2011
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:7
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Tidskriftsartikel (refereegranskat)abstract
- Invasive species can displace natives, and thus identifying the traits that make aliens successful is crucial for predicting and preventing biodiversity loss. Pathogens may play an important role in the invasive process, facilitating colonization of their hosts in new continents and islands. According to the Novel Weapon Hypothesis, colonizers may out-compete local native species by bringing with them novel pathogens to which native species are not adapted. In contrast, the Enemy Release Hypothesis suggests that flourishing colonizers are successful because they have left their pathogens behind. To assess the role of avian malaria and related haemosporidian parasites in the global spread of a common invasive bird, we examined the prevalence and genetic diversity of haemosporidian parasites (order Haemosporida, genera Plasmodium and Haemoproteus) infecting house sparrows (Passer domesticus). We sampled house sparrows (N = 1820) from 58 locations on 6 continents. All the samples were tested using PCR-based methods; blood films from the PCR-positive birds were examined microscopically to identify parasite species. The results show that haemosporidian parasites in the house sparrows' native range are replaced by species from local host-generalist parasite fauna in the alien environments of North and South America. Furthermore, sparrows in colonized regions displayed a lower diversity and prevalence of parasite infections. Because the house sparrow lost its native parasites when colonizing the American continents, the release from these natural enemies may have facilitated its invasion in the last two centuries. Our findings therefore reject the Novel Weapon Hypothesis and are concordant with the Enemy Release Hypothesis.
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| 2. |
- Dimitrov, Dimitar, et al.
(författare)
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Plasmodium spp.: An experimental study on vertebrate host susceptibility to avian malaria.
- 2015
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Ingår i: Experimental Parasitology. - : Elsevier BV. - 0014-4894. ; 148, s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- The interest in experimental studies on avian malaria caused by Plasmodium species has increased recently due to the need of direct information about host-parasite interactions. Numerous important issues (host susceptibility, development of infection, the resistance and tolerance to avian malaria) can be answered using experimental infections. However, specificity of genetically different lineages of malaria parasites and their isolates is largely unknown. This study reviews recent experimental studies and offers additional data about susceptibility of birds to several widespread cytochrome b (cyt b) lineages of Plasmodium species belonging to four subgenera. We exposed two domesticated avian hosts (canaries Serinus canaria and ducklings Anas platyrhynchos) and also 16 species of common wild European birds to malaria infections by intramuscular injection of infected blood and then tested them by microscopic examination and PCR-based methods. Our study confirms former field and experimental observations about low specificity and wide host-range of Plasmodium relictum (lineages SGS1 and GRW11) and P. circumflexum (lineage TURDUS1) belonging to the subgenera Haemamoeba and Giovannolaia, respectively. However, the specificity of different lineages and isolates of the same parasite lineage differed between species of exposed hosts. Several tested Novyella lineages were species specific, with a few cases of successful development in experimentally exposed birds. The majority of reported cases of mortality and high parasitaemia were observed during parasite co-infections. Canaries were susceptible mainly for the species of Haemamoeba and Giovannolaia, but were refractory to the majority of Novyella isolates. Ducklings were susceptible to three malaria infections (SGS1, TURDUS1 and COLL4), but parasitaemia was light (<0.01%) and transient in all exposed birds. This study provides novel information about susceptibility of avian hosts to a wide array of malaria parasite lineages, outlining directions for future experimental research on various aspects of biology and epidemiology of avian malaria.
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| 3. |
- Krizanauskiene, Asta, et al.
(författare)
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Molecular characterization of Haemoproteus sacharovi (Haemosporida, Haemoproteidae), a common parasite of columbiform birds, with remarks on classification of haemoproteids of doves and pigeons
- 2013
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Ingår i: Zootaxa. - 1175-5334. ; 3616:1, s. 85-94
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Tidskriftsartikel (refereegranskat)abstract
- Haemoproteus (Haemosporida, Haemoproteidae) is the largest genus of avian haemosporidian parasites, some species of which cause lethal diseases in birds. Subgenera Parahaemoproteus and Haemoproteus are usually accepted in this genus; these parasites are transmitted by biting midges (Ceratopogonidae) and hippoboscid flies (Hippoboscidae), respectively. As of yet, species of Parahaemoproteus have not been reported to infect doves and pigeons (Columbiformes), parasites of these birds have not been reported to be transmitted by biting midges (Ceratopogonidae). Applying microscopy and PCR based methods, we identified mitochondrial cytochrome b (cyt b) sequences of Haemoproteus sacharovi, a widespread parasite of doves and pigeons. Phylogenetic relationships of dove haemoproteids, which traditionally have been classified in the subgenus Haemoproteus, showed that H. sacharovi and H. turtur, common parasites of doves, branch in the clade with Parahaemoproteus species, indicating that these haemoproteids may belong to this subgenus and are likely transmitted by biting midges. This study provides barcodes for H. sacharovi, clarifies the taxonomic positions of H. sacharovi and H. turtur, and indicates directions for development of classification of avian haemoproteid species. Our analysis shows that the current subgeneric classification of avian haemoproteids is generally effective, but the position of some species may need to be revised.
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| 4. |
- Palinauskas, Vaidas, et al.
(författare)
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A new method for isolation of purified genomic DNA from haemosporidian parasites inhabiting nucleated red blood cells
- 2013
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Ingår i: Experimental Parasitology. - : Elsevier BV. - 0014-4894. ; 133:3, s. 275-280
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Tidskriftsartikel (refereegranskat)abstract
- During the last 10 years, whole genomes have been sequenced from an increasing number of organisms. However, there is still no data on complete genomes of avian and lizard Plasmodium spp. or other haemosporidian parasites. In contrast to mammals, bird and reptile red blood cells have nuclei and thus blood of these vertebrates contains high amount of host DNA; that complicates preparation of purified template DNA from haemosporidian parasites, which has been the main obstacle for genomic studies of these parasites. In the present study we describe a method that generates large amount of purified avian haemosporidian DNA. The method is based on a unique biological feature of haemosporidian parasites, namely that mature gametocytes in blood can be induced to exflagellate in vitro. This results in the development of numerous microgametes, which can be separated from host blood cells by simple centrifugation. Our results reveal that this straight forward method provides opportunities to collect pure parasite DNA material, which can be used as a template for various genetic analyses including whole genome sequencing of haemosporidians infecting birds and lizards. (c) 2012 Elsevier Inc. All rights reserved.
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| 5. |
- Palinauskas, Vaidas, et al.
(författare)
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Molecular characterization and distribution of Haemoproteus minutus (Haemosporida, Haemoproteidae): A pathogenic avian parasite
- 2013
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Ingår i: Parasitology International. - : Elsevier BV. - 1383-5769. ; 62:4, s. 358-363
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Tidskriftsartikel (refereegranskat)abstract
- Recently, the lineage hTURDUS2 of Haemoproteus minutus (Haemosporida, Haemoproteidae) was reported to cause mortality in captive parrots. This parasite lineage is widespread and prevalent in the blackbird Turdus merula throughout its entire distribution range. Species identity of other closely related lineages recently reported in dead parrots remains unclear, but will be important to determine for a better understanding of the epidemiology of haemoproteosis. Using polymerase chain reaction (PCR)-based and microscopic methods, we analyzed 265 blood samples collected from 52 species of wild birds in Eurasia (23 samples from Kamchatka Peninsula, 73 from Sakhalin Island, 150 from Ekaterinburg and 19 from Irkutsk regions of Russia). Single infections of the lineages hTURDUS2 (hosts are redwing Turdus iliacus and fieldfare Turdus pilaris), hTUPHI1 (song thrush Turdus philomelos) and hTUCHR01 (fieldfare, redwing, song thrush and brown-headed thrush Turdus chysolaus) were detected. We identified species of these haemoproteids based on morphology of their blood stages and conclude that these lineages belong to H. minutus, a widespread parasite of different species of thrushes (genus Turdus), which serve as reservoir hosts of this haemoproteid infection. Phylogenetic analysis shows that the lineages hTURDUS2, hTUCHR01 and hTUPHI1 of H. minutus are closely related to Haemoproteus pallidus (lineages hPFC1 and hCOLL2), Haemoproteus pallidulus (hSYAT03), and Haemoproteus sp. (hMEUND3); genetic distance among their mitochondrial cytochrome b (cyt b) lineages is small (<1% or <4 nucleotides). All these blood parasites are different in many morphological characters, but are similar due to one feature, which is the pale staining of their macrogametocytes' cytoplasm with Giemsa. Because of the recent publications about mortality caused by the lineages hTUPHI1 and hTURDUS2 of H. minutus in captive parrots in Europe, H. minutus and the closely related H. pallidus and H. pallidulus are worth more attention as these are possible agents of haemoproteosis in exotic birds. The present study provides barcodes for molecular detection of different lineages of H. minutus, and extends information about the distribution of this blood parasite. (C) 2013 Elsevier Ireland Ltd. All rights reserved.
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| 6. |
- Valkiunas, Gediminas, et al.
(författare)
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Polymerase chain reaction-based identification of Plasmodium (Huffia) elongatum, with remarks on species identity of haemosporidian lineages deposited in GenBank
- 2008
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Ingår i: Parasitology Reseach. - : Springer Science and Business Media LLC. - 1432-1955 .- 0932-0113. ; 102:6, s. 1185-1193
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Tidskriftsartikel (refereegranskat)abstract
- Numerous lineages of avian malaria parasites of the genus Plasmodium have been deposited in GenBank. However, only 11 morphospecies of Plasmodium have been linked to these lineages. Such linking is important because it provides opportunities to combine the existing knowledge of traditional parasitology with novel genetic information of these parasites obtained by molecular techniques. This study linked one mitochondrial cytochrome b (cyt b) gene lineage with morphospecies Plasmodium (Huffia) elongatum, a cosmopolitan avian malaria parasite which causes lethal disease in some birds. One species of Plasmodium (mitochondrial cyt b gene lineage P-GRW6) was isolated from naturally infected adult great reed warblers (Acrocephalus arundinaceus) and inoculated to one naive juvenile individual of the same host species. Heavy parasitaemia developed in the subinoculated bird, which enabled identification of the morphospecies and deposition of its voucher specimens. The parasite of this lineage belongs to P. elongatum. Illustrations of blood stages of this parasite are given. Other lineages closely related to P. elongatum were identified. The validity of the subgenus Huffia is supported by phylogenetic analysis. Mitochondrial cyt b gene lineages, with GenBank accession nos. AF069611 and AY733088, belong to Plasmodium cathemerium and P. elongatum, respectively; these lineages have been formerly attributed to P. elongatum and P. relictum, respectively. Some other incorrect species identifications of avian haematozoa in GenBank have been identified. We propose a strategy to minimise the number of such mistakes in GenBank in the future.
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