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- Ferraguti, Martina, et al.
(författare)
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Ecological determinants of avian malaria infections : An integrative analysis at landscape, mosquito and vertebrate community levels
- 2018
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Ingår i: Journal of Animal Ecology. - : Wiley. - 0021-8790. ; 87:3, s. 727-740
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Tidskriftsartikel (refereegranskat)abstract
- Vector and host communities, as well as habitat characteristics, may have important but different impacts on the prevalence, richness and evenness of vector-borne parasites. We investigated the relative importance of (1) the mosquito community composition, (2) the vertebrate community composition and (3) landscape characteristics on the prevalence, richness and evenness of avian Plasmodium. We hypothesized that parasite prevalence will be more affected by vector-related parameters, while host parameters should be also important to explain Plasmodium richness and evenness. We sampled 2,588 wild house sparrows (Passer domesticus) and 340,829 mosquitoes, and we performed vertebrate censuses at 45 localities in the Southwest of Spain. These localities included urban, rural and natural landscapes that were characterized by several habitat variables. Twelve Plasmodium lineages were identified in house sparrows corresponding to three major clades. Variation partitioning showed that landscape characteristics explained the highest fraction of variation in all response variables (21.0%-44.8%). Plasmodium prevalence was in addition explained by vector-related variables (5.4%) and its interaction with landscape (10.2%). Parasite richness and evenness were mostly explained by vertebrate community-related variables. The structuring role of landscape characteristics in vector and host communities was a key factor in determining parasite prevalence, richness and evenness, although the role of each factor differed according to the parasite parameters studied. These results show that the biotic and abiotic contexts are important to explain the transmission dynamics of mosquito-borne pathogens in the wild.
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2. |
- Ferraguti, Martina, et al.
(författare)
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From Africa to Europe : evidence of transmission of a tropical Plasmodium lineage in Spanish populations of house sparrows
- 2019
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Ingår i: Parasites & Vectors. - : Springer Science and Business Media LLC. - 1756-3305. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Avian malaria parasites are a highly diverse group that commonly infect birds and have deleterious effects on their hosts. Some parasite lineages are geographically widespread and infect many host species in many regions. Bird migration, natural dispersal, invasive species and human-mediated introductions into areas where competent insect vectors are present, are probably the main drivers of the current distribution of avian malaria parasites. METHODS: A total of 412 and 2588 wild house sparrows (Passer domesticus) were captured in 2012 and 2013 in two areas of the Iberian Peninsula (central and southern Spain, respectively). Genomic DNA was extracted from blood samples; parasite lineages were sequenced and identified by comparing with GenBank and/or MalAvi databases. RESULTS: Thirteen Plasmodium lineages were identified in house sparrows corresponding to three major clades. Five individuals were infected by the African Plasmodium lineage PAGRI02, which has been proposed to actively circulate only in Africa. CONCLUSIONS: Despite the low prevalence of PAGRI02 in sparrows in Spain, our results suggest that the area of transmission of this parasite is more widespread than previously thought and covers both Africa and Europe. Further studies of the global distribution of Plasmodium lineages infecting wild birds are required to identify the current transmission areas of these parasites. This is vital given the current scenario of global change that is providing new opportunities for avian malaria transmission into areas where parasites were previously absent.
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3. |
- Jiménez-Peñuela, Jéssica, et al.
(författare)
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Differences in fatty acids composition between Plasmodium infected and uninfected house sparrows along an urbanization gradient
- 2022
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697. ; 815
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic activities such as intensification of agriculture, animal husbandry and expansion of cities can negatively impact wildlife through its influence on the availability of high-quality food resources and pathogen transmission. The house sparrow (Passer domesticus), an urban exploiter, is undergoing a population decline. Nutritional constrains and infectious diseases has been highlighted as potential causes. Fatty acids (FAs) play an important role in modulating certain immune responses needed to combat parasite infections. FAs are highly influenced by dietary availability and have been shown to vary between urban and rural birds. Habitat anthropization also affects avian malaria epidemiology but little attention has been given to the relationship between blood parasite infection, host FAs composition and anthropization. Here, we analysed 165 juvenile birds either infected by Plasmodium or uninfected, captured at 15 localities grouped in triplets containing urban, rural and natural habitats. The total level of FAs was higher in birds from urban than from rural habitats, suggesting a greater availability of fat-rich foods sources. Furthermore, Plasmodium infected birds had higher relative levels of ω-3 polyunsaturated fatty acids (PUFAs) but lower of ω-6 PUFAs than uninfected birds. In concordance, the ω-6/ω-3 ratio was also lower in infected than in uninfected birds, but only from natural habitats, likely driven by the slightly higher ω-3 PUFAs in infected birds from natural habitats. Birds from anthropized environments may metabolize the ω-3 PUFAs to promote anti-inflammatory responses against stressors, which would result in lower ω-3 affecting their response against Plasmodium. Alternatively, lower ω-6 PUFAs may influence birds susceptibility to infection due to a weaker pro-inflammatory response. These descriptive results do not allow us to identify the causality of these associations but highlight the need to further investigate the relevance of FAs for birds to fight infectious diseases in habitats with different degree of urbanization.
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4. |
- Ruiz-Martinez, Jorge, et al.
(författare)
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Prevalence and Genetic Diversity of Avipoxvirus in House Sparrows in Spain
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:12
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Tidskriftsartikel (refereegranskat)abstract
- Avipoxvirus (APV) is a fairly common virus affecting birds that causes morbidity and mortality in wild and captive birds. We studied the prevalence of pox-like lesions and genetic diversity of APV in house sparrows (Passer domesticus) in natural, agricultural and urban areas in southern Spain in 2013 and 2014 and in central Spain for 8 months (2012-2013). Overall, 3.2% of 2,341 house sparrows visually examined in southern Spain had cutaneous lesions consistent with avian pox. A similar prevalence (3%) was found in 338 birds from central Spain. Prevalence was higher in hatch-year birds than in adults. We did not detect any clear spatial or temporal patterns of APV distribution. Molecular analyses of poxvirus-like lesions revealed that 63% of the samples were positive. Molecular and phylogenetic analyses of 29 DNA sequences from the fpv167 gene, detected two strains belonging to the canarypox clade (subclades B1 and B2) previously found in Spain. One of them appears predominant in Iberia and North Africa and shares 70% similarity to fowlpox and canarypox virus. This APV strain has been identified in a limited number of species in the Iberian Peninsula, Morocco and Hungary. The second one has a global distribution and has been found in numerous wild bird species around the world. To our knowledge, this represents the largest study of avian poxvirus disease in the broadly distributed house sparrow and strongly supports the findings that Avipox prevalence in this species in South and central Spain is moderate and the genetic diversity low.
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