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1.
Sci Rep ; 9(1): 10450, 2019 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-31320731

RESUMO

Calcium (Ca) is an essential element for almost all living organisms. Here, we examined global variation and controls of freshwater Ca concentrations, using 440 599 water samples from 43 184 inland water sites in 57 countries. We found that the global median Ca concentration was 4.0 mg L-1 with 20.7% of the water samples showing Ca concentrations ≤ 1.5 mg L-1, a threshold considered critical for the survival of many Ca-demanding organisms. Spatially, freshwater Ca concentrations were strongly and proportionally linked to carbonate alkalinity, with the highest Ca and carbonate alkalinity in waters with a pH around 8.0 and decreasing in concentrations towards lower pH. However, on a temporal scale, by analyzing decadal trends in >200 water bodies since the 1980s, we observed a frequent decoupling between carbonate alkalinity and Ca concentrations, which we attributed mainly to the influence of anthropogenic acid deposition. As acid deposition has been ameliorated, in many freshwaters carbonate alkalinity concentrations have increased or remained constant, while Ca concentrations have rapidly declined towards or even below pre-industrial conditions as a consequence of recovery from anthropogenic acidification. Thus, a paradoxical outcome of the successful remediation of acid deposition is a globally widespread freshwater Ca concentration decline towards critically low levels for many aquatic organisms.

2.
J Exp Biol ; 221(Pt 24)2018 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-30552290

RESUMO

Insect migrations are spectacular natural events and resemble a remarkable relocation of biomass between two locations in space. Unlike the well-known migrations of daytime flying butterflies, such as the painted lady (Vanessa cardui) or the monarch butterfly (Danaus plexippus), much less widely known are the migrations of nocturnal moths. These migrations - typically involving billions of moths from different taxa - have recently attracted considerable scientific attention. Nocturnal moth migrations have traditionally been investigated by light trapping and by observations in the wild, but in recent times a considerable improvement in our understanding of this phenomenon has come from studying insect orientation behaviour, using vertical-looking radar. In order to establish a new model organism to study compass mechanisms in migratory moths, we tethered each of two species of central European Noctuid moths in a flight simulator to study their flight bearings: the red underwing (Catocala nupta) and the large yellow underwing (Noctua pronuba). Both species had significantly oriented flight bearings under an unobscured view of the clear night sky and in the Earth's natural magnetic field. Red underwings oriented south-southeast, while large yellow underwings oriented southwest, both suggesting a southerly autumn migration towards the Mediterranean. Interestingly, large yellow underwings became disoriented on humid (foggy) nights while red underwings remained oriented. We found no evidence in either species for a time-independent sky compass mechanism as previously suggested for the large yellow underwing.


Assuntos
Migração Animal , Voo Animal , Mariposas/fisiologia , Orientação Espacial , Animais , Áustria , Europa (Continente) , Estações do Ano , Especificidade da Espécie
3.
Parasit Vectors ; 11(1): 456, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-30081963

RESUMO

BACKGROUND: Uranotaenia unguiculata Edwards, 1913 is a species of mosquito (Diptera: Culicidae) native to central Europe. Recently a novel lineage of the West Nile virus (WNV-lineage 4c) was identified in pools of adult female Ur. unguiculata. To increase the body of knowledge about this species, various trapping methods were evaluated to determine the most efficient method for capturing adult female Ur. unguiculata. RESULTS: Sound traps collected equivalent numbers of female Ur. unguiculata as low-hanging light-baited downdraft traps. Hosts were identified as Pelophylax lessonae and P. ridibunda (Anura: Ranidae) species group frogs from the blood found in engorged females. In addition to confirming infection by WNV-lin. 4c, a potentially integrated flavivirus sequence was detected in male mosquitoes. A novel Alphamesonivirus 1 (Nidovirales: Mesoniviridae) was found to be widespread in the Ur. unguiculata population and is herein described. CONCLUSIONS: Efficient collection methods for Ur. unguiculata for arbovirus surveillance reflect mosquito questing behavior. Uranotaenia unguiculata targets frog species which call from the water, and it is likely that the novel WNV-lin. 4c is maintained in a frog-mosquito transmission cycle. The improved trapping methods listed here will assist future studies of the vector status of Ur. unguiculata for WNV and other arboviruses.


Assuntos
Anfíbios , Culicidae/fisiologia , Comportamento Alimentar , Som , Vírus/classificação , Animais , Culicidae/virologia , Feminino , Masculino , Fenômenos Fisiológicos Virais
4.
Can J Infect Dis Med Microbiol ; 2018: 9754695, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29736197

RESUMO

Information on mosquito-borne filarioid helminths in Austria is scarce, but recent discoveries of Dirofilaria repens indicate autochthonous distribution of this parasite in Eastern Austria. In the current xenomonitoring study, more than 48,000 mosquitoes were collected in Eastern Austria between 2013 and 2015, using different sampling techniques and storage conditions, and were analysed in pools with molecular tools for the presence of filarioid helminth DNA. Overall, DNA of D. repens, Setaria tundra, and two unknown filarioid helminths were documented in twenty mosquito pools within the mitochondrial cox1 gene (barcode region). These results indicate that S. tundra, with roe deer as definite hosts, is common in Eastern Austria, with most occurrences in floodplain mosquitoes (e.g., Aedes vexans). Moreover, DNA of D. repens was found in an Anopheles plumbeus mosquito close to the Slovakian border, indicating that D. repens is endemic in low prevalence in Eastern Austria. This study shows that xenomonitoring is an adequate tool to analyse the presence of filarioid helminths, but results are influenced by mosquito sampling techniques, storage conditions, and molecular protocols.

5.
PLoS One ; 13(4): e0196052, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29672618

RESUMO

Trypanosomatid flagellates have not been studied in Austria in any detail. In this study, specific nested PCR, targeted on the ribosomal small subunit, was used to determine the occurrence and diversity of trypanosomatids in wild-caught mosquitoes sampled across Eastern Austria in the years 2014-2015. We collected a total of 29,975 mosquitoes of 19 species divided in 1680 pools. Of these, 298 (17.7%), representing 12 different mosquito species, were positive for trypanosomatid DNA. In total, seven trypanosomatid spp. were identified (three Trypanosoma, three Crithidia and one Herpetomonas species), with the highest parasite species diversity found in the mosquito host Coquillettidia richiardii. The most frequent parasite species belonged to the mammalian Trypanosoma theileri/cervi species complex (found in 105 pools; 6.3%). The avian species T. culicavium (found in 69 pools; 4.1%) was only detected in mosquitoes of the genus Culex, which corresponds to their preference for avian hosts. Monoxenous trypanosomatids of the genus Crithidia and Herpetomonas were found in 20 (1.3%) mosquito pools. One third (n = 98) of the trypanosomatid positive mosquito pools carried more than one parasite species. This is the first large scale study of trypanosomatid parasites in Austrian mosquitoes and our results are valuable in providing an overview of the diversity of these parasites in Austria.


Assuntos
Culicidae/parasitologia , Trypanosoma/classificação , Animais , Áustria , Biodiversidade , DNA de Protozoário , DNA Ribossômico , Filogenia , Análise de Sequência de DNA , Trypanosoma/genética , Tripanossomíase/parasitologia , Tripanossomíase/transmissão
6.
Malar J ; 16(1): 389, 2017 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-28962620

RESUMO

BACKGROUND: Insect vectors, namely mosquitoes (Diptera: Culicidae), are compulsory for malaria parasites (Plasmodium spp.) to complete their life cycle. Despite this, little is known about vector competence of different mosquito species for the transmission of avian malaria parasites. METHODS: In this study, nested PCR was used to determine Plasmodium spp. occurrence in pools of whole individuals, as well as the diversity of mitochondrial cytochrome b gene sequences in wild-caught mosquitoes sampled across Eastern Austria in 2013-2015. RESULTS: A total of 45,749 mosquitoes in 2628 pools were collected, of which 169 pools (6.43%) comprising 9 mosquito species were positive for avian Plasmodium, with the majority of positives in mosquitoes of Culex pipiens s.l./Culex torrentium. Six different avian Plasmodium lineages were found, the most common were Plasmodium vaughani SYAT05, Plasmodium sp. Linn1 and Plasmodium relictum SGS1. In 2014, mosquitoes of the Culex pipiens complex were genetically identified and Culex pipiens f. pipiens presented with the highest number of avian Plasmodium positives (n = 37; 16.74%). Despite this, the minimum infection rate (MIR) was highest in Culex torrentium (5.36%) and Culex pipiens f. pipiens/f. molestus hybrids (5.26%). During 2014 and 2015, seasonal and annual changes in Plasmodium lineage distribution were also observed. In both years P. vaughani SYAT05 dominated at the beginning of the sampling period to be replaced later in the year by P. relictum SGS1 (2014) and Plasmodium sp. Linn1 (2015). CONCLUSIONS: This is the first large-scale study of avian Plasmodium parasites in Austrian mosquitoes. These results are of special interest, because molecular identification of the taxa of the Cx. pipiens complex and Cx. torrentium enabled the determination of Plasmodium prevalence in the different mosquito taxa and hybrids of this complex. Since pools of whole insects were used, it is not possible to assert any vector competence in any of the examined mosquitoes, but the results are nonetheless valuable in providing an overview of avian Plasmodium species and lineages present in Austria.


Assuntos
Culex/parasitologia , Insetos Vetores/parasitologia , Malária Aviária/epidemiologia , Plasmodium/isolamento & purificação , Animais , Áustria/epidemiologia , Malária Aviária/parasitologia , Plasmodium/classificação , Plasmodium/genética , Análise de Sequência de DNA
7.
Parasit Vectors ; 10(1): 205, 2017 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-28441957

RESUMO

BACKGROUND: Vector-pathogen dynamics are controlled by fluctuations of potential vector communities, such as the Culicidae. Assessment of mosquito community diversity and, in particular, identification of environmental parameters shaping these communities is therefore of key importance for the design of adequate surveillance approaches. In this study, we assess effects of climatic parameters and habitat structure on mosquito communities in eastern Austria to deliver these highly relevant baseline data. METHODS: Female mosquitoes were sampled twice a month from April to October 2014 and 2015 at 35 permanent and 23 non-permanent trapping sites using carbon dioxide-baited traps. Differences in spatial and seasonal abundance patterns of Culicidae taxa were identified using likelihood ratio tests; possible effects of environmental parameters on seasonal and spatial mosquito distribution were analysed using multivariate statistical methods. We assessed community responses to environmental parameters based on 14-day-average values that affect ontogenesis. RESULTS: Altogether 29,734 female mosquitoes were collected, and 21 of 42 native as well as two of four non-native mosquito species were reconfirmed in eastern Austria. Statistical analyses revealed significant differences in mosquito abundance between sampling years and provinces. Incidence and abundance patterns were found to be linked to 14-day mean sunshine duration, humidity, water-level maxima and the amount of precipitation. However, land cover classes were found to be the most important factor, effectively assigning both indigenous and non-native mosquito species to various communities, which responded differentially to environmental variables. CONCLUSIONS: These findings thus underline the significance of non-climatic variables for future mosquito prediction models and the necessity to consider these in mosquito surveillance programmes.


Assuntos
Culicidae/crescimento & desenvolvimento , Ecossistema , Meio Ambiente , Insetos Vetores , Animais , Áustria , Clima , Culicidae/classificação , Densidade Demográfica , Estações do Ano , Análise Espaço-Temporal
8.
Parasit Vectors ; 9: 197, 2016 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-27067139

RESUMO

BACKGROUND: Culex pipiens complex taxa differ in behaviour, ecophysiology and epidemiologic importance. Despite their epidemiologic significance, information on genetic diversity, occurrence and seasonal and spatial distribution patterns of the Cx. pipiens complex is still insufficient. Assessment of seasonal and spatial distribution patterns of Culex pipiens forms and their congener Cx. torrentium is crucial for the understanding of their vector-pathogen dynamics. METHODS: Female mosquitoes were trapped from April-October 2014 twice a month for a 24-h time period with BG-sentinel traps at 24 sampling sites in eastern Austria, using carbon dioxide as attractant. Ecological forms of Cx. pipiens s.l. and their hybrids were differentiated using the CQ11 locus, and Cx. pipiens forms and their congener Cx. torrentium using the ACE-2 gene. Differential exploitation of ecological niches by Cx. pipiens forms and Cx. torrentium was analysed using likelihood ratio tests. Possible effects of environmental parameters on these taxa were tested using PERMANOVA based on distance matrices and, if significant, were modelled in nMDS ordination space to estimate non-linear relationships. RESULTS: For this study, 1476 Culex spp. were sampled. Culex pipiens f. pipiens representing 87.33 % of the total catch was most abundant, followed by hybrids of both forms (5.62 %), Cx. torrentium (3.79 %) and Cx. pipiens f. molestus (3.25 %). Differences in proportional abundances were found between land cover classes. Ecological parameters affecting seasonal and spatial distribution of these taxa in eastern Austria are precipitation duration, air temperature, sunlight and the interaction term of precipitation amount and the Danube water level, which can be interpreted as a proxy for breeding habitat availability. CONCLUSIONS: The Cx. pipiens complex of eastern Austria comprises both ecologically different forms, the mainly ornithophilic form pipiens and the mainly mammalophilic and anthropophilic form molestus. Heterogeneous agricultural areas as areas of coexistence may serve as hybridization zones, resulting in potential bridge vectors between birds and humans. Occurrence, seasonal and spatial distribution patterns of the Cx. pipiens complex and Cx. torrentium and the presence of hybrids between both forms were quantified for the first time in Austria. These findings will improve the knowledge of their vector-pathogen dynamics in this country.


Assuntos
Biota , Culex/classificação , Culex/crescimento & desenvolvimento , Variação Genética , Animais , Áustria , Culex/genética , Feminino , Estações do Ano , Análise de Sequência de DNA , Análise Espaço-Temporal
9.
ALTEX ; 22(3): 185-95, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16186994

RESUMO

Botulinum neurotoxin C1 (BoNt C1) and its corresponding gene were detected in seven aquatic habitats covering a range of low (LR) to high risk (HR) avian botulism outbreak areas during a study period of 10 months. Toxin and gene in sediment and avian faecal samples were analysed before (in situ) and after cultivation (in vitro) by a newly adapted ELISA, the common mouse bioassay and by a recently described nested PCR protocol. BoNt C1 gene fragments were detected in 74% and 83% of all investigated sediment samples by in situ PCR and in vitro PCR, respectively, at comparable frequencies in HR and LR areas. Similar high values were also observed for faecal samples. No BoNt C1 could be detected in the sediment in situ, while 53% and 56% of all cultivated samples contained BoNt C1 as detected in the mouse bioassay and the ELISA, respectively. The percentage of BoNt C1 positive cultivated samples was significantly higher (2-fold) in HR areas than in LR areas. Hence, our data clearly indicate an increased ratio of potentially BoNt C1 producing clostridia to BoNt C1 genes as the frequency or likelihood of botulinum epizootics increases in the environment. In addition, the good correlation between the results from the ELISA and the mouse bioassay for all sediment and faecal samples (r=0.90, p<0.001, n=121) indicates a high potential for the ELISA to reduce/replace the mouse bioassay for the detection of BoNt C1 in environmental samples.


Assuntos
Doenças das Aves/virologia , Toxinas Botulínicas/análise , Toxinas Botulínicas/genética , Botulismo/veterinária , Animais , Aves , Surtos de Doenças/veterinária , Meio Ambiente , Monitoramento Ambiental , Ensaio de Imunoadsorção Enzimática , Sedimentos Geológicos/análise , Camundongos , Reação em Cadeia da Polimerase
10.
Appl Environ Microbiol ; 70(12): 7396-403, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15574941

RESUMO

Wild birds are an important nonpoint source of fecal contamination of surface waters, but their contribution to fecal pollution is mostly difficult to estimate. Thus, to evaluate the relation between feces production and input of fecal indicator bacteria (FIB) into aquatic environments by wild waterfowl, we introduced a new holistic approach for evaluating the performance of FIB in six shallow saline habitats. For this, we monitored bird abundance, fecal pellet production, and the abundance of FIB concomitantly with a set of environmental variables over a 9-month period. For estimating fecal pellet production, a new protocol of fecal pellet counting was introduced, which was called fecal taxation (FTX). We could show that, over the whole range of investigated habitats, bird abundance, FTX values, and FIB abundance were highly significantly correlated and could demonstrate the good applicability of the FTX as a meaningful surrogate parameter for recent bird abundances and fecal contamination by birds in shallow aquatic ecosystems. Presumptive enterococci (ENT) were an excellent surrogate parameter of recent fecal contamination in these saline environments for samples collected at biweekly to monthly sampling intervals while presumptive Escherichia coli and fecal coliforms (FC) were often undetectable. Significant negative correlations with salinity indicated that E. coli and FC survival was hampered by osmotic stress. Statistical analyses further revealed that fecal pollution-associated parameters represented one system component independent from other environmental variables and that, besides feces production, rainfall, total suspended solids (direct), and trophy (indirect) had significant positive effects on ENT concentrations. Our holistic approach of linking bird abundance, feces production, and FIB detection with environmental variables may serve as a powerful model for application to other aquatic ecosystems.


Assuntos
Aves/fisiologia , Enterococcus/isolamento & purificação , Fezes/microbiologia , Água Doce/microbiologia , Cloreto de Sódio , Animais , Animais Selvagens/fisiologia , Áustria , Ecossistema , Enterobacteriaceae/isolamento & purificação , Enterococcus/crescimento & desenvolvimento , Monitoramento Ambiental/métodos , Escherichia coli/isolamento & purificação , Poluição da Água
11.
ALTEX ; 19 Suppl 1: 49-54, 2002.
Artigo em Alemão | MEDLINE | ID: mdl-12096330

RESUMO

Botulism is one of the most important bird diseases world-wide and is caused by the intoxication with Botulinum-Neurotoxin-C1 (BoNt-C1), which is produced by toxigenic clostridia under appropriate conditions. Avian botulism leads regularly to large losses among the migrating bird populations breeding and resting at the saltwater pools of the Austrian national park Neusiedler See-Seewinkel. Despite of its ethical dubiousness and its high technical expense the mouse-bioassay is still used as the routine standard method for the detection of BoNt-C1. According to the 3R-concept, in vitro alternative methods for the qualitative detection of BoNt-C1 (immunostick-ELISA) and a corresponding BoNt-C1 gene fragment (nested-PCR) were established. In order to estimate the BoNt-C1 production potential the methods were tested with sediment samples from different saltwater pools subjected to cultivation conditions appropriate for in vitro BoNt-C1-production. With the mouse-bioassay, 52 out of 77 samples were found to have a positive toxin production potential. The immunostick-ELISA showed a similar sensitivity as the mouse-bioassay and exhibited a highly significant positive correlation (r=0.94; p<0.001) with the mouse-bioassay in detecting BoNt-C1. The nested-PCR approach revealed higher numbers of positive BoNt-C1 gene fragment detections as compared to the direct toxin analysis approaches. A weak correlation (r=0.21; p=0.07) with the mouse-bioassay was discernible, no correlation was found with the immunostick-ELISA (r=0.09; p=0.46). Obviously, the PCR approach detected the BoNt-C1 gene fragment in some of the samples where no toxin expression has occurred. Thus it is suggested that the qualitative immunostick-ELISA represents a potential in-vitro alternative to the mouse-bioassay for assessing the BoNt-C1 production potential in environmental samples. In contrast, qualitative BoNt-C1 gene fragment detection via PCR led to an overestimation of the actual toxin production potential.


Assuntos
Alternativas aos Testes com Animais , Toxinas Botulínicas/análise , Poluentes Ambientais/análise , Ensaio de Imunoadsorção Enzimática/métodos , Reação em Cadeia da Polimerase/métodos , Animais , Sequência de Bases , Primers do DNA , Camundongos , Poli(ADP-Ribose) Polimerases/análise
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