53 research outputs found

    Morphometric and genetic characterization as tools for selection of Apis mellifera (Hymenoptera: Apidae) stocks in an area of natural hybridization in Argentina

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    Beekeepers around the world select bees’ characteristics that facilitate and favor production. In regions where hybridization among lineages is taking place, this selection is a challenge, given that these regions are “natural laboratories”, where the action of evolutionary processes of a population or species occurs in real time. A natural honeybee (Apis mellifera) hybrid zone exists in Argentina between 28° and 35° South, where Africanized (AHB) and European (EHB) populations converge. In this zone, beekeepers use selected genetic resources of European origin mostly, since the local Africanized bees show a higher defensive behavior, which is not desirable for management. Although EHB colonies have many advantages for honey production, they are not fully adapted to the subtropical climate and are susceptible to certain parasitosis such as varroosis. In addition, both AHB and EHB mate in drone congregation areas (DCAs), where males and virgin queens fly to meet, resulting in variability in the desired characteristics. In this study, we explored the degree of hybridization within a DCA and its reference apiary, located in the province of Entre Ríos, by applying two complementary techniques. First, morphotypes with different degrees of hybridization between European and African subspecies were observed in the reference apiary, indicating a high sensitivity of this morphometric approach to detect hybridization in these populations. Second, a genetic analysis revealed haplotypes of both origins for drones in DCAs, with a higher prevalence of European haplotypes, while all the colonies from the reference apiary exhibited European haplotypes. Overall, our results are in line with the strong impact that commercial beekeeping has on the genetics of DCAs. We show how wing morphometry may be used to monitor hybridization between European and African subspecies, a tool that may be evaluated in other regions of the world where hybridization occurs.Instituto de GenéticaFil: Litvinoff, Leonardo. Reinas del Litoral SRL; ArgentinaFil: Menescardi, Francisco. Reinas del Litoral SRL; ArgentinaFil: Porrini, Leonardo. Instituto de Investigaciones en Producción, Sanidad y Ambiente (CONICET-UNSAM). Centro de Investigación en Abejas Sociales; ArgentinaFil: Porrini, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Russo, Romina Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; ArgentinaFil: Russo, Romina Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Russo, Romina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Liendo, María Clara. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; ArgentinaFil: Liendo, María Clara. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Liendo, María Clara. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nucci, Alejandro. Instituto de Investigaciones en Producción, Sanidad y Ambiente (CONICET-UNSAM). Centro de Investigación en Abejas Sociales; ArgentinaFil: Nucci, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lusarreta, Esteban. Instituto de Investigaciones en Producción, Sanidad y Ambiente (CONICET-UNSAM). Centro de Investigación en Abejas Sociales; ArgentinaFil: Lusarreta, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ventura, Rocio. Instituto de Investigaciones en Producción, Sanidad y Ambiente (CONICET-UNSAM). Centro de Investigación en Abejas Sociales; ArgentinaFil: Ventura, Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Espasadin, Luna. Fundación Miguel Lillo. Instituto de Entomología; ArgentinaFil: Monmany-Garzia, A. Carolina. Universidad Nacional de Tucumán. Instituto de Ecología Regional; ArgentinaFil: Monmany-Garzia, A. Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scannapieco, Alejandra Carla. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; ArgentinaFil: Scannapieco, Alejandra Carla. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Scannapieco, Alejandra Carla. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Galindo Cardona, Alberto. Fundación Miguel Lillo. Instituto de Entomología; ArgentinaFil: Galindo Cardona, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Varroa destructor parasitism and genetic variability at honey bee (Apis mellifera) drone congregation areas and their associations with environmental variables in Argentina

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    Varroa destructor is a serious ectoparasite of the western honey bee, Apis mellifera, which negatively impacts on colonies health and survival worldwide. Drone-mediated movement and the presence of the mite in Drone Congregation Areas (DCA) may play a relevant role in Varroa dispersal. The objectives of this study were to characterize mite infestation levels and genetic diversity in DCAs and surrounding apiaries and to explore putative environmental variables associated to Varroa infestation in two eco-climatic regions of Argentina (temperate, and subtropical). Phoretic mite proportions in DCAs and apiaries were estimated during spring. Landscape, topographic, and climate variables were described using satellite image classifications and data from public databases. The genetic composition of drones at the DCAs and workers from the surrounding apiaries was assessed using mitochondrial markers. In total, eleven DCAs were identified in both regions during 2017 and 2018. The mean proportion of Varroa was ca. 3 in 1,000 (0.0028 ± 0.0046) at the apiaries, and ca. 2 in 100 (0.0168 ± 0.0227) at the DCAs. No statistical differences were observed between apiaries and DCAs or between ecoregions, but the proportion of infested males at the DCAs was positively correlated to the distance to the apiary and a trend was observed toward higher mite loads in DCAs. Landscape and topography were not determinant for Varroa infestation at the DCAs but relative humidity and precipitation in the previous week of sampling, positively influenced infestation. More haplotypic diversity was detected in the DCAs compared to the surrounding apiaries, particularly in the subtropical region. While in this region high prevalence of Africanized (A1, A4) mitochondrial lineages was detected, European lineages (C1, C2j) were mostly found in apiaries and DCA in the temperate region. Our results provide valuable information on the dynamics of Varroa parasitism in apiaries and DCAs, and highlight the role of drones in mite dispersion and genetic variability of new colonies. The study of DCAs emerges as a tool for investigating not only honey bee reproduction and conservation, but also the impact of the environment on bee epidemiology.Instituto de GenéticaFil: Galindo Cardona, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scannapieco, Alejandra Carla. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; Argentina.Fil: Russo, Romina María. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; ArgentinaFil: Escalante, Karen. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales; ArgentinaFil: Geria, Martín. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales; ArgentinaFil: Lepori, Nicolás. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales; ArgentinaFil: Ayup, María Marta. Universidad Nacional de Tucumán. Instituto de Ecología Regional; Argentina.Fil: Muntaabski, Irina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; Argentina.Fil: Liendo, María Clara. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; Argentina.Fil: Landi, Lucas. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Giray, Tugrul. Universidad de Puerto Rico. Departamento de Biología; Puerto RicoFil: Monmany-Garzia, A. Carolina. Universidad Nacional de Tucumán. Instituto de Ecología Regional; ArgentinaFil: Galindo Cardona, Alberto. Fundación Miguel Lillo; Argentina.Fil: Galindo Cardona, Alberto. Universidad Nacional de Tucumán. Instituto de Ecología Regional; ArgentinaFil: Scannapieco, Alejandra Carla. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ayup, María Marta. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales; ArgentinaFil: Muntaabski, Irina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Liendo, María Clara. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Universal Stress Proteins Are Important for Oxidative and Acid Stress Resistance and Growth of Listeria monocytogenes EGD-e In Vitro and In Vivo

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    Background: Pathogenic bacteria maintain a multifaceted apparatus to resist damage caused by external stimuli. As part of this, the universal stress protein A (UspA) and its homologues, initially discovered in Escherichia coli K-12 were shown to possess an important role in stress resistance and growth in several bacterial species. Methods and Findings: We conducted a study to assess the role of three homologous proteins containing the UspA domain in the facultative intracellular human pathogen Listeria monocytogenes under different stress conditions. The growth properties of three UspA deletion mutants (deltalmo0515, deltalmo1580 and deltalmo2673) were examined either following challenge with a sublethal concentration of hydrogen peroxide or under acidic conditions. We also examined their ability for intracellular survival within murine macrophages. Virulence and growth of usp mutants were further characterized in invertebrate and vertebrate infection models. Tolerance to acidic stress was clearly reduced in Δlmo1580 and deltalmo0515, while oxidative stress dramatically diminished growth in all mutants. Survival within macrophages was significantly decreased in deltalmo1580 and deltalmo2673 as compared to the wild-type strain. Viability of infected Galleria mellonella larvae was markedly higher when injected with deltalmo1580 or deltalmo2673 as compared to wild-type strain inoculation, indicating impaired virulence of bacteria lacking these usp genes. Finally, we observed severely restricted growth of all chromosomal deletion mutants in mice livers and spleens as compared to the load of wild-type bacteria following infection. Conclusion: This work provides distinct evidence that universal stress proteins are strongly involved in listerial stress response and survival under both in vitro and in vivo growth conditions

    Impact of biological agents on postsurgical complications in inflammatory bowel disease: A multicentre study of Geteccu

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    Background: The impact of biologics on the risk of postoperative complications (PC) in inflammatory bowel disease (IBD) is still an ongoing debate. This lack of evidence is more relevant for ustekinumab and vedolizumab. Aims: To evaluate the impact of biologics on the risk of PC. Methods: A retrospective study was performed in 37 centres. Patients treated with biologics within 12 weeks before surgery were considered “exposed”. The impact of the exposure on the risk of 30-day PC and the risk of infections was assessed by logistic regression and propensity score-matched analysis. Results: A total of 1535 surgeries were performed on 1370 patients. Of them, 711 surgeries were conducted in the exposed cohort (584 anti-TNF, 58 vedolizumab and 69 ustekinumab). In the multivariate analysis, male gender (OR: 1.5; 95% CI: 1.2–2.0), urgent surgery (OR: 1.6; 95% CI: 1.2–2.2), laparotomy approach (OR: 1.5; 95% CI: 1.1–1.9) and severe anaemia (OR: 1.8; 95% CI: 1.3–2.6) had higher risk of PC, while academic hospitals had significantly lower risk. Exposure to biologics (either anti-TNF, vedolizumab or ustekinumab) did not increase the risk of PC (OR: 1.2; 95% CI: 0.97–1.58), although it could be a risk factor for postoperative infections (OR 1.5; 95% CI: 1.03–2.27). Conclusions: Preoperative administration of biologics does not seem to be a risk factor for overall PC, although it may be so for postoperative infections

    A communal catalogue reveals Earth's multiscale microbial diversity

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    Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe

    A communal catalogue reveals Earth’s multiscale microbial diversity

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    Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Proceedings of the 24th Paediatric Rheumatology European Society Congress: Part three

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    From Springer Nature via Jisc Publications Router.Publication status: PublishedHistory: collection 2017-09, epub 2017-09-0

    DNA BARCODING FOR TARGETING INVASIVE SPECIES AND NATURAL CONTROL AGENTS IN THE CARIBBEAN

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    The development of DNA barcoding for species identification is a broad tool that has been emphasized in the recent decade. Since the 1980's, the increase of trade and exchange of goods has raised the number of invasive species reported. The new invaders are threatening the development of a sustainable agriculture, the preservation of natural habitats and raising the costs for urban landscaping. Molecular barcoding is part of an innovative approach to accurately identify and fingerprint life species. Barcoding methods are a valuable application for both pest ecology and biocontrol agents. Several universal mitochondrial and nuclear molecular markers of conservative regions such as Cytochrome Oxidase I (COI) and Internal transcribed spacer (ITS) have been used in barcoding for fingerprinting both pests and their natural enemies and have demonstrated high replication of results. Moreover, the development of new molecular markers targeting important arthropod and microorganism species has elucidated their taxonomic status. The objectives at the Center of Excellence for Quarantine and Invasive Species (CEQIS) laboratory are to generate and apply DNA barcoding tools and to build an integrative database of pests and beneficial organisms within the Caribbean and track their pathways. Current work at the laboratory addresses the identification of parasitoid communities associated to whiteflies in Solanaceae, Leguminosae and alternate host plants. Plant host species are also identified by both classic morphology and DNA barcoding. Barcoding clarifies discrepancies between morphological and molecular identification. Molecular approaches used clarify the taxonomy of the parasitoid complex associated to the Harrisia cactus mealybug, Hypogeococcus pungens. So far, other biological control agents have been targeted for barcoding at the CEQIS and include mites, coleopteran and coccinellid

    Landscape Analysis of Drone Congregation Areas of the Honey Bee, Apis mellifera

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    Male honey bees fly and gather at Drone Congregation Areas (DCAs), where drones and queens mate in flight. DCAs occur in places with presumably characteristic features. Using previously described landscape characteristics and observations on flight direction of drones in nearby apiaries, 36 candidate locations were chosen across the main island of Puerto Rico. At these locations, the presence or absence of DCAs was tested by lifting a helium balloon equipped with queen-sex-pheromone-impregnated bait, and visually determining the presence of high numbers of drones. Because of the wide distribution of honey bees in Puerto Rico, it was expected that most of the potential DCAs would be used as such by drones and queens from nearby colonies. Eight DCAs were found in the 36 candidate locations. Locations with and without DCAs were compared in a landscape analysis including characteristics that were described to be associated with DCAs and others. Aspect (direction of slope) and density of trails were found to be significantly associated with the presence of DCAs
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