501 research outputs found
The Echinococcus canadensis (G7) genome: A key knowledge of parasitic platyhelminth human diseases
Background: The parasite Echinococcus canadensis (G7) (phylum Platyhelminthes, class Cestoda) is one of the causative agents of echinococcosis. Echinococcosis is a worldwide chronic zoonosis affecting humans as well as domestic and wild mammals, which has been reported as a prioritized neglected disease by the World Health Organisation. No genomic data, comparative genomic analyses or efficient therapeutic and diagnostic tools are available for this severe disease. The information presented in this study will help to understand the peculiar biological characters and to design species-specific control tools. Results: We sequenced, assembled and annotated the 115-Mb genome of E. canadensis (G7). Comparative genomic analyses using whole genome data of three Echinococcus species not only confirmed the status of E. canadensis (G7) as a separate species but also demonstrated a high nucleotide sequences divergence in relation to E. granulosus (G1). The E. canadensis (G7) genome contains 11,449 genes with a core set of 881 orthologs shared among five cestode species. Comparative genomics revealed that there are more single nucleotide polymorphisms (SNPs) between E. canadensis (G7) and E. granulosus (G1) than between E. canadensis (G7) and E. multilocularis. This result was unexpected since E. canadensis (G7) and E. granulosus (G1) were considered to belong to the species complex E. granulosus sensu lato. We described SNPs in known drug targets and metabolism genes in the E. canadensis (G7) genome. Regarding gene regulation, we analysed three particular features: CpG island distribution along the three Echinococcus genomes, DNA methylation system and small RNA pathway. The results suggest the occurrence of yet unknown gene regulation mechanisms in Echinococcus. Conclusions: This is the first work that addresses Echinococcus comparative genomics. The resources presented here will promote the study of mechanisms of parasite development as well as new tools for drug discovery. The availability of a high-quality genome assembly is critical for fully exploring the biology of a pathogenic organism. The E. canadensis (G7) genome presented in this study provides a unique opportunity to address the genetic diversity among the genus Echinococcus and its particular developmental features. At present, there is no unequivocal taxonomic classification of Echinococcus species; however, the genome-wide SNPs analysis performed here revealed the phylogenetic distance among these three Echinococcus species. Additional cestode genomes need to be sequenced to be able to resolve their phylogeny.Fil: Maldonado, Lucas Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Assis, Juliana. Fundación Oswaldo Cruz; BrasilFil: Gomes Araújo, Flávio M.. Fundación Oswaldo Cruz; BrasilFil: Salim, Anna C. M.. Fundación Oswaldo Cruz; BrasilFil: Macchiaroli, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Cucher, Marcela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Camicia, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Fox, Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Rosenzvit, Mara Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Oliveira, Guilherme. Instituto Tecnológico Vale; Brasil. Fundación Oswaldo Cruz; BrasilFil: Kamenetzky, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin
Evolution of Chagas’ disease in Brazil. Epidemiological perspective and challenges for the future: a critical review
Aims: This paper aimed to provide a critical review of the evolution of Chagas’ disease in Brazil, its magnitude, historical development and management, and challenges for the future.
Methods: A literature search was performed using PubMed, SciELO and Google Scholar and throughout collected articles’ references. Narrative analysis was structured around five main themes identified: vector transmission, control program, and transfusion, oral and congenital transmission.
Results: In Brazil, the Chagas’ disease Control Program was fully implemented in the 1980s, when it reached practically all the endemic areas, and in 1991, the Southern Cone Initiative was created, aiming to eliminate the disease transmission through eliminating the Triatoma infestans and controlling blood banks. As a result, the prevalence of chagasic donors in blood banks reduced from 4.4% in the 80s to 0.2% in 2005. In 2006, PAHO certified the interruption of transmission of Chagas’ disease through this vector in Brazil. However, there are still challenges, such as the domiciliation of new vector species, the need for medical care of the infected individuals, the prevention of alternative mechanisms of transmission, the loss of political concern regarding the disease and, the weakening of the control program.
Conclusion: Despite the progress towards control, there are still many challenges ahead to maintain and expand such control and minimise the risk of re-emergence
Drivers of Cape Verde archipelagic endemism in keyhole limpets
Oceanic archipelagos are the ideal setting for investigating processes that shape species assemblages. Focusing on keyhole limpets, genera Fissurella and Diodora from Cape Verde Islands, we used an integrative approach combining molecular phylogenetics with ocean transport simulations to infer species distribution patterns and analyse connectivity. Dispersal simulations, using pelagic larval duration and ocean currents as proxies, showed a reduced level of connectivity despite short distances between some of the islands. It is suggested that dispersal and persistence driven by patterns of oceanic circulation favouring self-recruitment played a primary role in explaining contemporary species distributions. Mitochondrial and nuclear data revealed the existence of eight Cape Verde endemic lineages, seven within Fissurella, distributed across the archipelago, and one within Diodora restricted to Boavista. The estimated origins for endemic Fissurella and Diodora were 10.2 and 6.7 MY, respectively. Between 9.5 and 4.5 MY, an intense period of volcanism in Boavista might have affected Diodora, preventing its diversification. Having originated earlier, Fissurella might have had more opportunities to disperse to other islands and speciate before those events. Bayesian analyses showed increased diversification rates in Fissurella possibly promoted by low sea levels during Plio-Pleistocene, which further explain differences in species richness between both genera.FCT - Portuguese Science Foundation [SFRH/BPD/109685/2015, SFRH/BPD/111003/2015]; Norte Portugal Regional Operational Program (NORTE), under the PORTUGAL Partnership Agreement, through the European Regional Development Fund (ERDF) [MARINFO - NORTE-01-0145-FEDER-000031]info:eu-repo/semantics/publishedVersio
Hyperdominance in the Amazonian tree flora
The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.4%) account for half of all trees. Most of these are habitat specialists and only dominant in one or two regions of the basin. We discuss some implications of the finding that a small group of species--less diverse than the North American tree flora--accounts for half of the world's most diverse tree community.This work was
supported by Alberta Mennega Stichting; ALCOA Suriname;
Banco de la República; Center for Agricultural Research in
Suriname; Coordenação de Aperfeiçoamento de Pessoal de
Nível Superior (Plano Nacional de Pós-Graduação); Conselho
Nacional de Desenvovimento Científico e Tecnológico of Brazil
(CNPq) projects Programa de Pesquisas Ecológicas de Longa
Duração (PELD) (558069/2009-6), Programa de Apoio a
Núcleos de Excelência da Fundação de Amparo à Pesquisa
do Estado do Amazonas (PRONEX-FAPEAM) (1600/2006), Áreas
Úmidas, and MAUA; PELD (403792/2012-6), PPBio, CENBAM,
Universal (479599/2008-4), and Universal 307807-2009-6;
Fundação de Amparo À Pesquisa Do Estado Do Amazonas
(APEAM) projects DCR/2006, Hidroveg with FAPESP, and
PRONEX with CNPq; FAPESP; Colciencias; Duke University;
Ecopetrol; FEPIM 044/2003; the Field Museum; Conservation
International/DC (TEAM/INPA Manuas), Gordon and Betty
Moore Foundation; Guyana Forestry Commission; Investissement
d’Avenir grant of the French Agence Nationale de la Recherche
(ANR) (Centre d’Étude de la Biodiversité Amazonienne
ANR-10-LABX-0025); Margaret Mee Amazon Trust; Miquel
fonds; National Geographic Society (7754-04, 8047-06 to
P.M.J.); Netherlands Foundation for the Advancement of
Tropical Research WOTRO grants WB85- 335 and W84-581;
Primate Conservation Incorporated; Programme Ecosystèmes
Tropicaux (French Ministry of Ecology and Sustainable
Development; Shell Prospecting and Development Peru;
Smithsonian Institution’s Biological Diversity of the Guiana
Shield Program; Stichting het van Eeden-fonds; the Body
Shop; the Ministry of the Environment of Ecuador;
TROBIT; Tropenbos International; NSF (NSF-0743457 and
NSF-0101775 to P.M.J.); USAID; Variety Woods Guyana;
WWF-Brazil; WWF-Guianas; XIIéme Contrat de Plan Etat
Région-Guyane (French Government and European Union); and
grants to RAINFOR from the European Union, UK Natural
Environment Research Council, the Gordon and Betty Moore
Foundation, and U.S. National Geographic Society. O.L.P. is
supported by a European Research Council Advanced Grant and a
Royal Society Wolfson Research Merit Award
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Socioeconomic development, family income, and psychosocial risk factors: a study of families with children in public elementary school
This article aims to evaluate the effects of Brazil's recent economic growth on the monetary income, consumption patterns, and risk exposures of families with children enrolled in the public elementary school system in São Gonçalo, Rio de Janeiro State, Brazil. The article analyzes the following information on families of 447 children that participated in two waves in a longitudinal study: social stratum, per capita family income, evolution in income over a three-year period, and psychosocial factors. The findings showed a 74.8% increase in the families' income, accompanied by an increase in the consumption of material assets and access to health services. This increase should not be interpreted as a guarantee of improved living and health conditions, since it was spent on basic products and needs that do not substantially affect the families' form of social inclusion. Psychosocial risk factors were frequent among the families, but decreased during the study period, which may either reflect the improved family situation or result from the later stage in child development.O objetivo deste artigo é avaliar os reflexos do recente crescimento econômico brasileiro sobre o rendimento monetário, o padrão de consumo familiar e os riscos em que vivem famílias da rede pública do Ensino Fundamental do Município de São Gonçalo, Rio de Janeiro, Brasil. São analisadas as seguintes informações sobre as famílias de 447 crianças que participaram de duas ondas de estudo longitudinal: estrato social, renda familiar per capita, evolução de renda no período e fatores psicossociais. Os resultados indicam incremento financeiro em 74,8% das famílias, acompanhado de aumento no consumo de bens materiais e no acesso a serviços de saúde. Esse crescimento não pode ser tomado como garantia de melhoria nas condições de vida e saúde, já que é gasto com a aquisição de produtos e necessidades básicas que não chegam a afetar substancialmente a forma de inserção social em que vivem as famílias. Os fatores de risco psicossociais mostraram-se frequentes, porém decrescentes nas famílias estudadas, o que pode refletir a melhoria da situação de vida familiar ou ser decorrente da etapa do desenvolvimento infantil
The Aspergillus fumigatus CrzA Transcription Factor Activates Chitin Synthase Gene Expression during the Caspofungin Paradoxical Effect
This is the final version. Available from American Society for Microbiology via the DOI in this record. Aspergillus fumigatus is an opportunistic fungal pathogen that causes
invasive aspergillosis (IA), a life-threatening disease in immunocompromised humans.
The echinocandin caspofungin, adopted as a second-line therapy in combating IA, is
a -1,3-glucan synthase inhibitor, which, when used in high concentrations, reverts
the anticipated A. fumigatus growth inhibition, a phenomenon called the “caspofungin
paradoxical effect” (CPE). The CPE has been widely associated with increased chitin
content in the cell wall due to a compensatory upregulation of chitin synthaseencoding
genes. Here, we demonstrate that the CPE is dependent on the cell wall
integrity (CWI) mitogen-activated protein kinase MpkAMPK1 and its associated transcription
factor (TF) RlmARLM1, which regulate chitin synthase gene expression in response
to different concentrations of caspofungin. Furthermore, the calcium- and
calcineurin-dependent TF CrzA binds to and regulates the expression of specific chitin
synthase genes during the CPE. These results suggest that the regulation of cell
wall biosynthetic genes occurs by several cellular signaling pathways. In addition,
CrzA is also involved in cell wall organization in the absence of caspofungin. Differences
in the CPE were also observed between two A. fumigatus clinical isolates,
which led to the identification of a novel basic leucine zipper TF, termed ZipD. This
TF functions in the calcium-calcineurin pathway and is involved in the regulation of
cell wall biosynthesis genes. This study therefore unraveled additional mechanisms
and novel factors governing the CPE response, which ultimately could aid in developing
more effective antifungal therapies.CNPqFAPES
The infection of microvascular endothelial cells with ExoU-producing Pseudomonas aeruginosa triggers the release of von Willebrand factor and platelet adhesion
An increased plasma concentration of von Willebrand factor (vWF) is detected in individuals with many infectious diseases and is accepted as a marker of endothelium activation and prothrombotic condition. To determine whether ExoU, a Pseudomonas aeruginosa cytotoxin with proinflammatory activity, enhances the release of vWF, microvascular endothelial cells were infected with the ExoU-producing PA103 P. aeruginosa strain or an exoU-deficient mutant. Significantly increased vWF concentrations were detected in conditioned medium and subendothelial extracellular matrix from cultures infected with the wild-type bacteria, as determined by enzyme-linked immunoassays. PA103-infected cells also released higher concentrations of procoagulant microparticles containing increased amounts of membrane-associated vWF, as determined by flow cytometric analyses of cell culture supernatants. Both flow cytometry and confocal microscopy showed that increased amounts of vWF were associated with cytoplasmic membranes from cells infected with the ExoU-producing bacteria. PA103-infected cultures exposed to platelet suspensions exhibited increased percentages of cells with platelet adhesion. Because no modulation of the vWF mRNA levels was detected by reverse transcription-polymerase chain reaction assays in PA103-infected cells, ExoU is likely to have induced the release of vWF from cytoplasmic stores rather than vWF gene transcription. Such release is likely to modify the thromboresistance of microvascular endothelial cells
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