43 research outputs found

    A novel Hepacivirus in wild rodents from South America

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    The Hepacivirus genus comprises single-stranded positive-sense RNA viruses within the family Flaviviridae. Several hepaciviruses have been identified in different mammals, including multiple rodent species in Africa, Asia, Europe, and North America. To date, no rodent hepacivirus has been identified in the South American continent. Here, we describe an unknown hepacivirus discovered during a metagenomic screen in Akodon montensis, Calomys tener, Oligoryzomys nigripes, Necromys lasiurus, and Mus musculus from São Paulo State, Brazil. Molecular detection of this novel hepacivirus by RT-PCR showed a frequency of 11.11% (2/18) in Oligoryzomys nigripes. This is the first identification of hepavivirus in sigmondonine rodents and in rodents from South America. In sum, our results expand the host range, viral diversity, and geographical distribution of the Hepacivirus genus

    The influence of sugarcane pre‐harvest fire on hantavirus prevalence in Neotropical small mammals

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    The use of pre-harvest fire in sugarcane fields surprisingly results in an increase in the abundance of Neotropical Sigmodontinae rodents, which might carry hantavirus. By contrast, fire suspension induces a decline in rodents in the first 5 years. The present study aimed to evaluate the effect of sugarcane harvest regimes on hantavirus prevalence in wild rodents. Field collections were carried out on a sugarcane production area in Northeast S˜ao Paulo, which is responsible for 30% of the ethanol production in Brazil. A few years after pre-harvest fire suspension, a high prevalence of hantavirus was found in small rodents at lower population density, but apparently higher population growth rate. Differences in life cycle between the rodents and their predators may explain such density patterns, as small rodents can breed twice or even three times each year, whereas their predators usually breed only once a year. Similarly, the temporal dynamics of the predator–prey relationship suggests that hantavirus prevalence is related to small rodent’s population growth and not density. Only Akodon montensis, Calomys tener, and Necromys lasiurus contained immunoglobulin G antibodiesagainst the recombinant nucleoprotein of Araraquara orthohantavirus, a genotype of Andes orthohantavirus, with no interspecific variation in seroprevalence among these species. However, males presented higher prevalence rate than females, possibly due to a male-biased dispersal pattern and a higher frequency of antagonistic interactions. Governance measures to mitigate the role of small wild rodents on the emergence of hantavirus in agricultural landscapes dominated by sugarcane plantations should include the use of wildlife-friendly management techniques (e.g., to mitigate the mortality of the predators of small rodents), human capacity building concerning wildlife-related conflicts, and multifunctionality of agricultural landscapes. Future studies should prioritize the possible relationship between microhabitat structure and hantavirus prevalence in small rodents in agricultural landscapes dominated by sugarcane fields.info:eu-repo/semantics/publishedVersio

    Novel orthohepeviruses in wild rodents from São Paulo State, Brazil

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    The Hepeviridae comprise single-stranded positive-sense RNA viruses classified into two genera, Orthohepevirus and Piscihepevirus. Orthohepeviruses have a wide host range that includes rodents, but previous studies had been restricted to rodents of the Muridae family. In this study, we applied a high-throughput sequencing approach to examine the presence of orthohepeviruses in rodents from São Paulo State, Brazil. We also used RT-PCR to determine the frequency of orthohepeviruses in our sampled population. We identified novel orthohepeviruses in blood samples derived from Necromys lasiurus (1.19%) and Calomys tener (3.66%). Therefore, our results expand the host range and viral diversity of the Hepeviridae family

    Spatiotemporal Dynamics of Hantavirus Cardiopulmonary Syndrome Transmission Risk in Brazil

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    Background: Hantavirus disease in humans is rare but frequently lethal in the Neotropics. Several abundant and widely distributed Sigmodontinae rodents are the primary hosts of Orthohantavirus and, in combination with other factors, these rodents can shape hantavirus disease. Here, we assessed the influence of host diversity, climate, social vulnerability and land use change on the risk of hantavirus disease in Brazil over 24 years. Methods: Landscape variables (native forest, forestry, sugarcane, maize and pasture), climate (temperature and precipitation), and host biodiversity (derived through niche models) were used in spatiotemporal models, using the 5570 Brazilian municipalities as units of analysis. Results: Amounts of native forest and sugarcane, combined with temperature, were the most important factors influencing the increase of disease risk. Population at risk (rural workers) and rodent host diversity also had a positive effect on disease risk. Conclusions: Land use change—especially the conversion of native areas to sugarcane fields—can have a significant impact on hantavirus disease risk, likely by promoting the interaction between the people and the infected rodents. Our results demonstrate the importance of understanding the interactions between landscape change, rodent diversity, and hantavirus disease incidence, and suggest that land use policy should consider disease risk. Meanwhile, our risk map can be used to help allocate preventive measures to avoid disease.publishedVersio

    Novel parvoviruses from wild and domestic animals in Brazil provide new insights into parvovirus distribution and diversity

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    Parvoviruses (family Parvoviridae) are small, single-stranded DNA viruses. Many parvoviral pathogens of medical, veterinary and ecological importance have been identified. In this study, we used high-throughput sequencing (HTS) to investigate the diversity of parvoviruses infecting wild and domestic animals in Brazil. We identified 21 parvovirus sequences (including twelve nearly complete genomes and nine partial genomes) in samples derived from rodents, bats, opossums, birds and cattle in Pernambuco, São Paulo, Paraná and Rio Grande do Sul states. These sequences were investigated using phylogenetic and distance-based approaches and were thereby classified into eight parvovirus species (six of which have not been described previously), representing six distinct genera in the subfamily Parvovirinae. Our findings extend the known biogeographic range of previously characterized parvovirus species and the known host range of three parvovirus genera (Dependovirus, Aveparvovirus and Tetraparvovirus). Moreover, our investigation provides a window into the ecological dynamics of parvovirus infections in vertebrates, revealing that many parvovirus genera contain well-defined sub-lineages that circulate widely throughout the world within particular taxonomic groups of hosts

    Incidência e morfometria do forame oval patente em cadáveres humanos

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    Objetivo: Investigar a incidência e morfometria do FOP em corações humanos cadavéricos, sabendo que o método e a acuidade do exame diagnóstico interferem na estimativa da incidência do FOP. Método: Noventa corações humanos foram selecionados da coleção de partes de cadáveres do Departamento de Anatomia da UFPE. Incluídos no estudo estavam corações humanos que apresentavam os átrios direito e esquerdo dissecados para visualização das estruturas internas, bem como o septo interatrial intacto (sem dissecção). Corações cujos átrios foram removidos para visualização do plano valvar ou os átrios, não foram dissecados, foram excluídos. O estudo foi dividido em três etapas, a saber: (1) triagem e seleção de corações humanos; (2) investigação da presença de PFO em corações humanos selecionados; e (3) morfometria do PFO. Após a triagem, 40 corações humanos cadavéricos foram selecionados para estudar a incidência e a morfometria do FOP. Em cada coração humano cadavérico, o septo interatrial, a fossa oval e seu limbo foram analisados, e a presença ou ausência do FOP pelo átrio direito e pelo átrio esquerdo. Para realizar a morfometria, foi utilizado um paquímetro digital e medidos os diâmetros vertical e horizontal do FOP. Resultados: Dos 40 corações humanos selecionados, apenas seis apresentavam o FOP, indicando uma incidência de 15%. O FOP variou de 1 a 5 mm no diâmetro potencial máximo (média = 3,5 mm). Além disso, em um dos corações foi observada a existência de dois forames ovais. Conclusão: Com base nos resultados, foi observada uma incidência de 15% do FOP, com uma média de 3,5 mm de diâmetro potencial máximo

    Análise da ação da Terapia Fotodinâmica como coadjuvante no processo de desinfecção do sistema de canais radiculares: uma revisão narrativa

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    Objetivo: Apresentar a terapia fotodinâmica antimicrobiana como auxiliar no processo de desinfecção do sistema de canais radiculares. Revisão Bibliográfica: Os microrganismos nas patologias dentárias apresentam papel principal na etiologia das infecções endodônticas, caracterizadas como multibacterianas, mistas, primárias ou  secundárias. Bactérias resistentes e falhas durante a limpeza e desinfecção dos canais radiculares são os principais motivos do insucesso endodôntico. Estudos apontam a terapia fotodinâmica antimicrobiana como alternativa coadjuvante ao tratamento convencional para os cirurgiões-dentistas, a fim de eliminar as principais causas dos microrganismos que sobreviveram após o preparo químico-mecânico dos canais radiculares, diminuindo assim a taxa de insucesso do tratamento endodôntico. Considerações finais: O efeito antimicrobiano da interação  de uma fonte de luz com o agente fotossensibilizador surge como uma terapia auxiliar promissora ao tratamento endodôntico convencional, portanto, faz-se necessário a realização de estudos aprofundados para    que se obtenha um protocolo eficaz preestabelecido, visando o tratamento com maior índice de sucesso

    Inquérito sorológico retrospectivo das infecções por hantavirus no município de Cássia dos Coqueiros, Estado de São Paulo, Brasil

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    INTRODUCTION: In recent years, hantavirus infections producing severe diseases have obtained an increased attention from public health authorities from the countries of Eurasia to the Americas. Brazil has reported 1,300 cases of hantavirus cardiopulmonary syndrome (HCPS) from 1993 to 2010, with about 80 of them occurring in the northeast of the State of São Paulo, with 48% fatality rate. Araraquara virus was the causative agent of HCPS in the region. Considering that hantaviruses causing human disease in the Americas were unknown until 1993, we have looked for hantavirus infections in the population of Cássia dos Coqueiros county, northeast of the State of São Paulo, Brazil, before this time. This county has about 2,800 inhabitants and an economy based on agriculture, including cultivation of Brachiaria decumbens grass. The grass seeds are an important rodent attraction, facilitating transmission of hantavirus to man. Four HCPS cases were reported so far in the county. METHODS: In this study, 1,876 sera collected from 1987 to 1990 were tested for IgG to hantavirus by IgG-ELISA, using the N recombinant protein of Araraquara virus as antigen. RESULTS: Positive results were observed in 89 (4.7%) samples, which were all collected in 1987. The positivity among urban inhabitants was 5.3%, compared with 4.3% among those living in rural areas. CONCLUSIONS: Our results showed that hantavirus infections occurred in Cássia dos Coqueiros, completely unrecognized, even before hantaviruses were described in the Americas

    Discovery of novel anelloviruses in small mammals expands the host range and diversity of the Anelloviridae

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    The Anelloviridae comprises single-stranded DNA viruses currently grouped in sixty-eight species classified in twelve genera. They have been found in many vertebrate hosts including primates. In this study, we describe the application of the high-throughput sequencing to examine the frequency and diversity of anelloviruses in rodents, bats and opossums captured in São Paulo State, Brazil. We report a total of twenty-six anelloviruses with sixteen nearly complete genomes and ten partial genomes, which include eleven potential novel species identified in rodents (Cricetidae), bats (Molossidae and Phyllostomidae), and opossums (Didelphidae). We also propose the inclusion of two potential new genera within the Anelloviridae family, provisionally named Omegatorquevirus and Sigmatorquevirus, including six and three novel species of anelloviruses, respectively. In summary, this study expands the diversity and the host range of the known anelloviruses
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