17 research outputs found

    A field trial of a PCR-based Mansonella ozzardi diagnosis assay detects high-levels of submicroscopic M. ozzardi infections in both venous blood samples and FTA® card dried blood spots

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    BACKGROUND: Mansonella ozzardi is a poorly understood human filarial parasite with a broad distribution throughout Latin America. Most of what is known about its parasitism has come from epidemiological studies that have estimated parasite incidence using light microscopy. Light microscopy can, however, miss lighter, submicroscopic, infections. In this study we have compared M. ozzardi incidence estimates made using light microscopy, with estimates made using PCR. METHODS: 214 DNA extracts made from Large Volume Venous Blood Samples (LVVBS) were taken from volunteers from two study sites in the Rio Solimões region: Codajás [n = 109] and Tefé [n = 105] and were subsequently assayed for M. ozzardi parasitism using a diagnostic PCR (Mo-dPCR). Peripheral finger-prick blood samples were taken from the same individuals and used for microscopic examination. Finger-prick blood, taken from individuals from Tefé, was also used for the creation of FTAcard dried blood spots (DBS) that were subsequently subjected to Mo-dPCR. RESULTS: Overall M. ozzardi incidence estimates made with LVVBS PCRs were 1.8 times higher than those made using microscopy (44.9% [96/214] compared with 24.3% [52/214]) and 1.5 times higher than the PCR estimates made from FTAcard DBS (48/105 versus 31/105). PCR-based detection of FTAcard DBS proved 1.3 times more sensitive at diagnosing infections from peripheral blood samples than light microscopy did: detecting 24/105 compared with 31/105. PCR of LVVBS reported the fewest number of false negatives, detecting: 44 of 52 (84.6%) individuals diagnosed by microscopy; 27 of 31 (87.1%) of those diagnosed positive from DBSs and 17 out of 18 (94.4%) of those diagnosed as positive by both alternative methodologies. CONCLUSIONS: In this study, Mo-dPCR of LVVBS was by far the most sensitive method of detecting M. ozzardi infections and detected submicroscopic infections. Mo-dPCR FTAcard DBS also provided a more sensitive test for M. ozzardi diagnosis than light microscopy based diagnosis did and thus in settings where only finger-prick assays can be carried-out, it may be a more reliable method of detection. Most existing M. ozzardi incidence estimates, which are often based on light microscope diagnosis, are likely to dramatically underestimate true M. ozzardi parasitism incidence levels.Jansen Fernandes de Medeiros had financial support from edital PPSUS FAPEAM/SUSAM/MS/CNPq 007/2009. FAPEAM also provided finical support for the work of: Tatiana Amaral Pires de Almeida; Lucyane Bastos Tavares da Silva and J. Lee Crainey. The authors would like to thank Ricardo Mota and personal at Tefé for their technical assistance and two referees for their useful comments, which have helped to improve the manuscript. This paper is contribution number 23 of the Research Programme on Infectious Disease Ecology in the Amazon (RP-IDEA) of the Instituto Leônidas and Maria Deane—Fiocruz Amazônia.S

    SARS-CoV-2 in the Amazon region

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    A medida que la pandemia del Síndrome Respiratorio Agudo Severo Coronavirus 2 (SARS-CoV-2) continúa expandiéndose, los recursos de atención médica a nivel mundial se han reducido. Ahora, la enfermedad es extendiéndose rápidamente por América del Sur, con consecuencias mortales en áreas con ya sistemas de salud pública debilitados. La región amazónica es particularmente susceptible a la devastación generalizada de la enfermedad por coronavirus 2019 (COVID-19) debido a sus habitantes amerindios nativos inmunológicamente frágiles y vulnerabilidades epidemiológicas. Aquí, nosotros discutir la situación actual y el impacto potencial de COVID-19 en la región amazónica y cómo una mayor propagación de la ola epidémica podría resultar devastadora para muchas personas amerindias que viven en la selva amazónicaAs the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic continues to expand, healthcare resources globally have been spread thin. Now, the disease is rapidly spreading across South America, with deadly consequences in areas with already weakened public health systems. The Amazon region is particularly susceptible to the widespread devastation from Coronavirus disease 2019 (COVID-19) because of its immunologically fragile native Amerindian inhabitants and epidemiologic vulnerabilities. Herein, we discuss the current situation and potential impact of COVID-19 in the Amazon region and how further spread of the epidemic wave could prove devastating for many Amerindian people living in the Amazon rainfores

    Multidrug resistant Pseudomonas aeruginosa survey in a stream receiving effluents from ineffective wastewater hospital plants

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    Background: Multi-drug resistant forms of Pseudomonas aeruginosa (MDRPA) are a major source of nosocomial infections and when discharged into streams and rivers from hospital wastewater treatment plants (HWWTP) they are known to be able to persist for extended periods. In the city of Manaus (Western Brazilian Amazon), the effluent of three HWWTPs feed into the urban Mindu stream which crosses the city from its rainforest source before draining into the Rio Negro. The stream is routinely used by Manaus residents for bathing and cleaning (of clothes as well as domestic utensils) and, during periods of flooding, can contaminate wells used for drinking water. Results: 16S rRNA metagenomic sequence analysis of 293 cloned PCR fragments, detected an abundance of Pseudomonas aeruginosa (P. aeruginosa) at the stream's Rio Negro drainage site, but failed to detect it at the stream's source. An array of antimicrobial resistance profiles and resistance to all 14 tested antimicrobials was detected among P. aeruginosa cultures prepared from wastewater samples taken from water entering and being discharged from a Manaus HWWTP. Just one P. aeruginosa antimicrobial resistance profile, however, was detected from cultures made from Mindu stream isolates. Comparisons made between P. aeruginosa isolates' genomic DNA restriction enzyme digest fingerprints, failed to determine if any of the P. aeruginosa found in the Mindu stream were of HWWTP origin, but suggested that Mindu stream P. aeruginosa are from diverse origins. Culturing experiments also showed that P. aeruginosa biofilm formation and the extent of biofilm formation produced were both significantly higher in multi drug resistant forms of P. aeruginosa. Conclusions: Our results show that a diverse range of MDRPA are being discharged in an urban stream from a HWWTP in Manaus and that P. aeruginosa strains with ampicillin and amikacin can persist well within it. © 2016 The Author(s)

    Inheritance, diversity and evolutionary significance of mosquito APE retroposons

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    Outstanding insecurities concerning the use of an Ov16-based ELISA in the Amazonia onchocerciasis focus

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    In a recent issue of Memórias do Instituto Oswaldo Cruz, published in Rio de Janeiro in February 2014 (109: 87-92), Adami et al. have published a survey reporting Mansonella parasite prevalence in the Amazon Region. This report makes a useful contribution to the existing knowledge of filarial parasite distribution within the Amazon area, parasite prevalence rates in relation to age and occupation and provides observations on the possible clinical impact of Mansonella ozzardi. Their publication also provides an account of what appears to be a novel ELISA that has recently been used in the Simuliidae and Onchocerciasis Laboratory of the Oswaldo Cruz Institute, Rio de Janeiro, Brazil. We are concerned that the publication of this ELISA may have created an excessively positive impression of the effectiveness of the onchocerciasis recrudescence serological surveillance tools that are presently available for use in the Amazonia onchocerciasis focus. In this letter we have, thus, sought to highlight some of the limitations of this ELISA and suggest how continuing insecurities concerning the detection of antibodies to Onchocerca volvulus within the Amazonia onchocerciasis focus might be minimised.Financial support: FIOCRUZ, FAPEAM, CNPq *All papers undertaken by the LSO resulting from either research, collections and reference services are done with total independence and without conflict of interest with relation to their partners or supporters (Brazilian Health Ministry, OEPA) among others.S

    New tools and insights to assist with the molecular identification of Simulium guianense s.l., main Onchocerca volvulus vector within the highland areas of the Amazonia onchocerciasis focus

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    Following the success of the Onchocerciasis Elimination Programme for the Americas (OEPA), there is now just one Latin American onchocerciasis focus where onchocerciasis transmission is described as 'on-going:' the Amazonia Onchocerciasis focus. In the hyperendemic highland areas of the Amazonia focus, Simulium guianense s.l. Wise are the most important vectors of the disease. Populations of S. guianense s.l. are, however, known to vary in their cytogenetics and in a range of behaviours, including in their biting habits. In the hypoendemic lowland areas of the Amazonia focus, for example, S. guianense s.l. are generally regarded as zoophilic and consequently unimportant to disease transmission. Robust tools, to discriminate among various populations of S. guianense s.l. have, however, not yet been developed. In the work reported here, we have assessed the utility of a ribosomal DNA sequence fragment spanning the nuclear ribosomal ITS-1, ITS-2 and 5.8S sequence regions and a ~850 nucleotide portion of the mitochondrial cytochrome oxidase gene (CO1) for species-level identification and for resolving the within species substructuring. We report here how we have generated 78 CO1 sequences from a rich set of both zoophilic and anthropophilic populations of S. guianense s.l. that were collected from eight sites that are broadly distributed across Brazil. Consistent with previous findings, our analysis supports the genetic isolation of Simulium litobranchium from S. guianense s.l. In contrast with previous findings, however, our results did not provide support for the divergence of the two species prior to the radiation of S. guianense s.l. In our analysis of the S. guianense s.l. ribosomal DNA sequence trace files we generated, we provide clear evidence of multiple within-specimen single nucleotide polymorphisms and indels suggesting that S. guianense s.l. ribosomal DNA is not a good target for conventional DNA barcoding. This is the first report of S. guianense s.l. within individual ribosomal DNA variation and thus the first evidence that the species is not subject to the normal effects of concerted evolution. Collectively, these data illustrate the need for diverse sampling in the development of robust molecular tools for vector identification and suggest that ribosomal DNA might be able to assist with resolving S. guianense s.l. species substructuring that C01 barcoding has hitherto failed to. © 2013 Elsevier B.V

    Mansonella ozzardi mitogenome and pseudogene characterisation provides new perspectives on filarial parasite systematics and CO-1 barcoding

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    Submitted by Sandra Infurna ([email protected]) on 2019-02-10T19:44:55Z No. of bitstreams: 1 anaC_paulovicente_etal_IOC_2018.pdf: 3212561 bytes, checksum: fca129c97dce54b8af3939fae4a1876c (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-02-10T19:57:37Z (GMT) No. of bitstreams: 1 anaC_paulovicente_etal_IOC_2018.pdf: 3212561 bytes, checksum: fca129c97dce54b8af3939fae4a1876c (MD5)Made available in DSpace on 2019-02-10T19:57:37Z (GMT). No. of bitstreams: 1 anaC_paulovicente_etal_IOC_2018.pdf: 3212561 bytes, checksum: fca129c97dce54b8af3939fae4a1876c (MD5) Previous issue date: 2018Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Genética Molecular de Microrganismos. Rio de Janeiro, RJ, Brasil / University of La Frontera. Scientific and Technological Bioresource Nucleus. Temuco, Chile.Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Laboratório de Entomologia. Porto Velho, RO, Brasil.Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil / Programa de Pós-Graduação em Biologia da Interação Patógeno Hospedeiro. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Genética Molecular de Microrganismos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil.Despite the broad distribution of M. ozzardi in Latin America and the Caribbean, there is still very little DNA sequence data available to study this neglected parasite's epidemiology. Mitochondrial DNA (mtDNA) sequences, especially the cytochrome oxidase (CO1) gene's barcoding region, have been targeted successfully for filarial diagnostics and for epidemiological, ecological and evolutionary studies. MtDNA-based studies can, however, be compromised by unrecognised mitochondrial pseudogenes, such as Numts. Here, we have used shot-gun Illumina-HiSeq sequencing to recover the first complete Mansonella genus mitogenome and to identify several mitochondrial-origin pseudogenes. Mitogenome phylogenetic analysis placed M. ozzardi in the Onchocercidae "ONC5" clade and suggested that Mansonella parasites are more closely related to Wuchereria and Brugia genera parasites than they are to Loa genus parasites. DNA sequence alignments, BLAST searches and conceptual translations have been used to compliment phylogenetic analysis showing that M. ozzardi from the Amazon and Caribbean regions are near-identical and that previously reported Peruvian M. ozzardi CO1 reference sequences are probably of pseudogene origin. In addition to adding a much-needed resource to the Mansonella genus's molecular tool-kit and providing evidence that some M. ozzardi CO1 sequence deposits are pseudogenes, our results suggest that all Neotropical M. ozzardi parasites are closely related

    Molecular Verification of New World Mansonella perstans Parasitemias

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    We obtained ribosomal and mitochondrial DNA sequences from residents of Amazonas state, Brazil, with Mansonella parasitemias. Phylogenetic analysis of these sequences confirm that M. ozzardi and M. perstans parasites occur in sympatry and reveal the close relationship between M. perstans in Africa and Brazil, providing insights into the parasite’s New World origins
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