25 research outputs found

    Identification of <i>Trichomonas vaginalis</i> alpha-actinin as the most common immunogen recognized by sera of women exposed to the parasite

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    A study on presence of antibodies to Trichomonis vaginalis in serum was done on a group of 500 pregnant, asymptomatic Angolan women. A serologic screening, done by ELISA, revealed that 41% of the women had IgG and IgM against the parasite. Analysis of sera by immunoblotting revealed that 94.4% of sera with anti-T. vaginalis IgG class antibodies were reactive against a common immunogenic protein of 115 kDa. The common immunogen was identified as the protozoan α-actinin. All sera recognizing the 115-kDa antigen were reactive against both native and recombinant T. vaginalis α-actinin and nonreactive against human α-actinin. The findings presented in this work offer a new tool for epidemiologic studies and open new perspectives for vaccination

    Infecção natural por Trypanosoma cruzi em um cão na região central do Brasil: relato de caso

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    RESUMO Trypanosoma cruzi, infecta cerca de 10 milhões de pessoas, principalmente na América Latina e mais de 25 milhões apresentam-se em risco de adquirir a doença nas áreas endêmicas. Os cães são considerados importantes reservatórios representando fator de risco para a população humana. Este relato descreve caso de doença de Chagas em cão na cidade de Cuiabá. O diagnóstico foi feito a partir do exame direto, apresentando inúmeras formas tripomastigotas em esfregaço sanguíneo. Amastigotas foram visualizadas na microscopia de medula óssea, linfonodo, rins, fígado e cérebro. A infecção por T. cruzi (ZIII) foi confirmado através do sequenciamento de produtos amplificados pela PCR. O animal apresentou sinais multissistêmicos, evoluindo para óbito. Apesar da doença de Chagas aguda em humanos não ser descrita em Cuiabá, este é o primeiro relato de um caso canino nessa região, fato que, constitui alerta aos profissionais da saúde e autoridades sanitárias para a possibilidade da transmissão desta zoonose em Cuiabá.SUMMARY It is estimated that about 10 million people are infected with Trypanosoma cruzi worldwide, mostly in Latin America and more than 25 million are at risk of acquiring this infection in endemic areas. Dogs are an important reservoir for this pathogen and thus, considered a risk factor for human populations. This report describes one case of Chagas disease in a dog from Cuiabá, Mato Grosso State, Brazil. The diagnosis was obtained by direct examination of trypomastigote forms in blood smears. Amastigotes forms were visualized in microscopy of the bone marrow, lymph nodes, kidneys, liver and brain. The T. cruzi (ZIII) infection was confirmed by Polymerase Chain Reaction, and sequencing. The animal presented multisystemic failure and died. Although acute Chagas disease in humans is not reported in Cuiabá, this is the first report of a canine case in this region. This case represents a warning, to health professionals and authorities, to the possibility of transmission of this zoonosis in Cuiabá

    Participation of heparin binding proteins from the surface of Leishmania (Viannia) braziliensis promastigotes in the adhesion of parasites to Lutzomyia longipalpis cells (Lulo) in vitro

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    Background: Leishmania (V.) braziliensis is a causative agent of cutaneous leishmaniasis in Brazil. During the parasite life cycle, the promastigotes adhere to the gut of sandflies, to avoid being eliminated with the dejection. the Lulo cell line, derived from Lutzomyia longipalpis (Diptera: Psychodidae), is a suitable in vitro study model to understand the features of parasite adhesion. Here, we analyze the role of glycosaminoglycans (GAGs) from Lulo cells and proteins from the parasites in this event.Methods: Flagellar (F-f) and membrane (M-f) fractions from promastigotes were obtained by differential centrifugation and the purity of fractions confirmed by western blot assays, using specific antibodies for cellular compartments. Heparin-binding proteins (HBP) were isolated from both fractions using a HiTrap-Heparin column. in addition, binding of promastigotes to Lulo cells or to a heparin-coated surface was assessed by inhibition assays or surface plasmon resonance (SPR) analysis.Results: the success of promastigotes subcellular fractionation led to the obtainment of F-f and M-f proteins, both of which presented two main protein bands (65.0 and 55.0kDa) with affinity to heparin. the contribution of HBPs in the adherence of promastigotes to Lulo cells was assessed through competition assays, using HS or the purified HBPs fractions. All tested samples presented a measurable inhibition rate when compared to control adhesion rate (17 +/- 2.0% of culture cells with adhered parasites): 30% (for HS 20 mu g/ml) and 16% (for HS 10 mu g/ml); HBP M-f (35.2% for 10 mu g/ml and 25.4% for 20 mu g/ml) and HBP F-f (10.0% for 10 mu g/ml and 31.4% for 20 mu g/ml). Additionally, to verify the presence of sulfated GAGs in Lulo cells surface and intracellular compartment, metabolic labeling with radioactive sulfate was performed, indicating the presence of an HS and chondroitin sulfate in both cell sections. the SPR analysis performed further confirmed the presence of GAGs ligands on L. (V.) braziliensis promastigote surfaces.Conclusions: the data presented here point to evidences that HBPs present on the surface of L. (V.) braziliensis promastigotes participate in adhesion of these parasites to Lulo cells through HS participation.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Lab Biol Mol & Doencas Endem, BR-21040360 Rio de Janeiro, BrazilLab Ultraestrutura Celular, BR-21040360 Rio de Janeiro, BrazilFiocruz MS, IOC, Lab Bioquim & Fisiol Insetos, BR-21040360 Rio de Janeiro, BrazilFiocruz MS, IPEC, Lab Vigilancia Leishmanioses, BR-21040360 Rio de Janeiro, BrazilUniversidade Federal de São Paulo, UNIFESP, Dept Bioquim, São Paulo, BrazilUniv Rosario, Escuela Med, Bogota, DC, ColombiaUniversidade Federal de São Paulo, UNIFESP, Dept Bioquim, São Paulo, BrazilCNPq: 300731/2010-8CNPq: 509737/2010-2CAPES: EDITAL - 11/2009FAPERJ: E-26/103.060/2008FAPERJ: E-26/110.257/2010Web of Scienc

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Voluntary subsidy: contemporary Diplomatics and the contextualization of 18th century documents from Minas Gerais

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    O códice registrado no Arquivo do Instituto de Estudos Brasileiros da Universidade de São Paulo como AL014, formado por documentos diplomáticos setecentistas, corpus desta pesquisa, é analisado com base no caminho percorrido desde a sua produção, em sedes administrativas, até o seu uso como objeto de estudo científico, social e cultural, nos arquivos permanentes. O objetivo, na primeira parte, consiste na apresentação do códice e dos manuscritos, da sua história e materialidade e da análise formal desses documentos diplomáticos de arquivo, considerados individualmente, pela metodologia da Diplomática, a partir da identificação dos elementos externos, intermediários e internos que os constituem, de maneira a obter-se, como resultado, a demonstração da compatibilidade entre sua estrutura formal e sua natureza jurídica. Na segunda parte desta dissertação, aborda-se o segundo testemunho dos documentos, abrigado no Arquivo Histórico Ultramarino, sob a perspectiva do conceito conhecido como archival bond, definido como a rede de relações que cada registro possui com os registros do mesmo fundo documental. Neste trabalho, utiliza-se da metodologia da análise tipológica, ou Diplomática contemporânea, para verificar sua autenticidade em relação ao contexto orgânico em que os documentos estão inseridos, para demonstrar, como resultado, a narração inédita dos trâmites realizados desde a metrópole, para o estabelecimento do subsídio voluntário nas Capitanias do Brasil, mais especificamente na Capitania de Minas Gerais e na Vila Real de Sabará, de onde parte a Representação de 1777, que reivindica o fim da cobrança desse imposto.The codex recorded in the archive of the Institute of Brazilian Studies of the University of São Paulo as AL 014, formed by eighteenth century diplomatic documents, corpus of this research, was analyzed based on the path taken from its production, in administrative headquarters, to its use as an object of scientific, social and cultural study, in the permanent archives. The objective, in the first part, is the presentation of the codex and manuscripts, their history and materiality, and the formal analysis of these diplomatic archive documents, considered individually, by the methodology of Diplomatics, from the identification of their external, intermediate and internal elements, in order to obtain, as a result, the demonstration of the compatibility between their formal structure and their legal nature. In the second part of this dissertation, we approach the second testimony of the documents, housed in the Arquivo Histórico Ultramarino, from the perspective of the concept known as archival bond, defined as the network of relationships that each record has with the records of the same documentary fund. In this work, we use the methodology of typological analysis, or contemporary Diplomatics, to verify its authenticity in relation to the organic context in which the documents are inserted, in order to demonstrate, as a result, the unpublished narration of the procedures carried out since the metropolis, for the establishment of the voluntary subsidy in the captaincies of Brazil, more specifically in the captaincy of Minas Gerais and at Vila Real de Sabará, from where the Representation of 1777 departs, claiming an end to the collection of this tax

    Genotypic profiles of Leishmania (Viannia) braziliensis strains from cutaneous leishmaniasis patients and their relationship with the response to meglumine antimoniate treatment: a pilot study

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    Background: Forty-four strains isolated from a cohort of cutaneous leishmaniasis (CL) patients who did or did not respond to one course of treatment with meglumine antimoniate were investigated to explore genetic polymorphisms in parasite kinetoplast DNA minicircles. Leishmania (Viannia) braziliensis strains isolated from responder (R) and non-responder (NR) patients who acquired infection in Rio de Janeiro or in other Brazilian states were studied using low-stringency single-specific primer polymerase chain reaction (LSSP-PCR) to identify genetic polymorphisms. Results: Polymorphisms were observed in parasites recovered from patient lesions. No association was found between a specific genotype and R or NR patients. Phenetic analysis grouped the genotypes into three main clusters, with similarity indices varying from 0.72 to 1.00. Although no specific genotype association was detected, at least one group of L. (V.) braziliensis genotypes that circulates in Rio de Janeiro was discriminated in clusters I and III, showing phenotypes of good and poor responses to treatment, respectively. Cluster I comprised parasite profiles recovered from R patients from Rio de Janeiro and in cluster III, NR samples were prevalent. Cluster II comprised 24 isolates, with 21 from Rio de Janeiro and three from other states, equally distributed between R and NR patients. Additionally, we found that parasites sharing all common genetic characteristics acted differently in response to treatment. Conclusions: These results are of clinical-epidemiological importance since they demonstrate that populations of L. (V.) braziliensis that exhibit high levels of genetic similarity also display different phenotypes associated with meglumine antimoniate responses in cutaneous leishmaniasis patients

    Evaluation of Leishmania (Leishmania) chagasi strains isolated from dogs originating from two visceral leishmaniasis-endemic areas in Brazil using multilocus enzyme electrophoresis

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    INTRODUCTION: Domestic dogs are the most important reservoir in the peridomestic transmission cycle of Leishmania (Leishmania) chagasi. The genetic variability of subpopulations of this parasite circulating in dogs has not been thoroughly analyzed in Brazil, even though this knowledge has important implications in the clinical-epidemiological context. METHODS: The objective of this study was to evaluate and compare the phenotypic variability of 153 L. chagasi strains isolated from dogs originating from the municipalities of Rio de Janeiro (n = 57) and Belo Horizonte (n = 96), where the disease is endemic. Strains isolated only from intact skin were selected and analyzed by multilocus enzyme electrophoresis using nine enzyme systems (6PG, GPI, NH1 and NH2, G6P, PGM, MDH, ME, and IDHNADP). RESULTS: The electrophoretic profile was identical for all isolates analyzed and was the same as that of the L. chagasi reference strain (MHOM/BR/74/PP75). Phenetic analysis showed a similarity index of one for all strains, with the isolates sharing 100% of the characteristics analyzed. CONCLUSIONS: The results demonstrate that the L. chagasi populations circulating in dogs from Rio de Janeiro and Belo Horizonte belong to a single zymodeme

    Genotypic profiles of

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    Background: Forty-four strains isolated from a cohort of cutaneous leishmaniasis (CL) patients who did or did not respond to one course of treatment with meglumine antimoniate were investigated to explore genetic polymorphisms in parasite kinetoplast DNA minicircles. Leishmania (Viannia) braziliensis strains isolated from responder (R) and non-responder (NR) patients who acquired infection in Rio de Janeiro or in other Brazilian states were studied using low-stringency single-specific primer polymerase chain reaction (LSSP-PCR) to identify genetic polymorphisms. Results: Polymorphisms were observed in parasites recovered from patient lesions. No association was found between a specific genotype and R or NR patients. Phenetic analysis grouped the genotypes into three main clusters, with similarity indices varying from 0.72 to 1.00. Although no specific genotype association was detected, at least one group of L. (V.) braziliensis genotypes that circulates in Rio de Janeiro was discriminated in clusters I and III, showing phenotypes of good and poor responses to treatment, respectively. Cluster I comprised parasite profiles recovered from R patients from Rio de Janeiro and in cluster III, NR samples were prevalent. Cluster II comprised 24 isolates, with 21 from Rio de Janeiro and three from other states, equally distributed between R and NR patients. Additionally, we found that parasites sharing all common genetic characteristics acted differently in response to treatment. Conclusions: These results are of clinical-epidemiological importance since they demonstrate that populations of L. (V.) braziliensis that exhibit high levels of genetic similarity also display different phenotypes associated with meglumine antimoniate responses in cutaneous leishmaniasis patients

    Evaluation of Leishmania (Leishmania) chagasi strains isolated from dogs originating from two visceral leishmaniasis-endemic areas in Brazil using multilocus enzyme electrophoresis Avaliação de amostras de Leishmania (Leishmania) chagasi isoladas de cães oriundos de duas áreas endêmicas de leishmaniose visceral no Brasil através da eletroforese de isoenzimas

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    INTRODUCTION: Domestic dogs are the most important reservoir in the peridomestic transmission cycle of Leishmania (Leishmania) chagasi. The genetic variability of subpopulations of this parasite circulating in dogs has not been thoroughly analyzed in Brazil, even though this knowledge has important implications in the clinical-epidemiological context. METHODS: The objective of this study was to evaluate and compare the phenotypic variability of 153 L. chagasi strains isolated from dogs originating from the municipalities of Rio de Janeiro (n = 57) and Belo Horizonte (n = 96), where the disease is endemic. Strains isolated only from intact skin were selected and analyzed by multilocus enzyme electrophoresis using nine enzyme systems (6PG, GPI, NH1 and NH2, G6P, PGM, MDH, ME, and IDHNADP). RESULTS: The electrophoretic profile was identical for all isolates analyzed and was the same as that of the L. chagasi reference strain (MHOM/BR/74/PP75). Phenetic analysis showed a similarity index of one for all strains, with the isolates sharing 100% of the characteristics analyzed. CONCLUSIONS: The results demonstrate that the L. chagasi populations circulating in dogs from Rio de Janeiro and Belo Horizonte belong to a single zymodeme.<br>INTRODUÇÃO: Cães domésticos são considerados os reservatórios mais importantes no ciclo peridoméstico de transmissão de Leishmania (Leishmania) chagasi. No entanto, a variabilidade genética de sub-populações que circulam neste hospedeiro é ainda pouco explorada no Brasil, sendo tal conhecimento de grande importância no contexto clínico-epidemiológico. MÉTODOS: O objetivo deste estudo foi avaliar e comparar a variabilidade fenotípica de 153 amostras de L. chagasi isoladas de cães oriundos dos municípios do Rio de Janeiro (n = 57) e Belo Horizonte (n = 96), onde a doença é endêmica. Foram selecionadas somente amostras isoladas de pele íntegra e analisadas por eletroforese de isoenzimas (MLEE) empregando nove sistemas enzimáticos (6PG, GPI, NH1 e NH2, G6P, PGM, MDH, ME, IDHNADP). RESULTADOS: Todas as amostras analisadas apresentaram perfil eletroforético idêntico entre si e com a amostra de L. chagasi utilizada como referência neste estudo (MHOM/BR/74/PP75). A análise fenética demonstrou índice de similaridade igual a um para todas as amostras, revelando um compartilhamento de 100% dos caracteres avaliados. CONCLUSÕES: A partir desses resultados, podemos inferir que as populações de L. chagasi que estão circulando nos cães do Rio de Janeiro e Belo Horizonte podem ser agrupadas em um único zimodema
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