Abstract in English:The population of Brazil is currently characterised by many individuals harbouring low-intensity Schistosoma mansoni infections. The Kato-Katz technique is the diagnostic method recommended by the World Health Organization (WHO) to assess these infections, but this method is not sensitive enough in the context of low egg excretion. In this regard, potential alternatives are being employed to overcome the limits of the Kato-Katz technique. In the present review, we evaluated the performance of parasitological and immunological approaches adopted in Brazilian areas. Currently, the diagnostic choices involve a combination of strategies, including the utilisation of antibody methods to screen individuals and then subsequent confirmation of positive cases by intensive parasitological investigations.
Abstract in English:BACKGROUND Amazon, the largest tropical forest of the world, has suffered from dengue outbreaks since 1998. Cerebrospinal fluid (CSF) of patients, from Amazonas state, suspected of central nervous system (CNS) viral infection was studied using molecular and immunological methods. OBJECTIVE To evaluate the importance of CSF investigation in patients with acute dengue virus (DENV) infection of CNS. METHODS CSF samples of 700 patients were analysed by reverse transcription polymerase chain reaction (RT-PCR) to detect the presence of dengue virus (DENV) RNA and by enzyme-linked immunosorbent assay (ELISA) to detect presence of DENV specific IgM. FINDINGS DENV infection was detected in 4.3% of the CSF samples; 85.7% (24/28) by DENV IgM and 14.3% (4/28) by viral RNA. DENV detected by viral RNA were to be found serotypes DENV-2 (three patients) and DENV-1 (one patient). The neurological diagnosis in patients CNS infection of DENV included encephalitis (10), meningoencephalitis (10), meningitis (6), acute myelitis (1), and encephalomyelitis (1). The majority (89.3%) had intrathecal inflammation: pleocytosis, hyperproteinorrachia and DENV IgM antibodies. Hypoglycorrhachia and/or high levels of lactate in CSF were found in 36% of the patients. Co-infection (CMV, HIV, EBV, and/or Mycobacterium tuberculosis) was observed in eight (28.6%) cases. CONCLUSIONS We found intense inflammatory CSF that is unusual in CNS disorders caused by dengue infection. It may be due co-infections or the immunogenetic background of the local Amerindian Brazilian population. CSF examination is an important diagnostic support tool for neurological dengue diagnosis.
Abstract in English:BACKGROUND Epigenetic modifications in host cells, like p16 ink4a methylation, have been considered as putative complementary mechanisms for cancer development. Because only a small proportion of infected women develop cervical cancer, other factors might be involved in carcinogenesis, either independently or in association with high-risk human papillomavirus (HR-HPV) infections, including epigenetic factors. OBJECTIVES We hypothesised that p16 ink4a methylation might have a role in cancer development driven by HPV16, mainly in the presence of intact E1/E2 genes. Thus, our objectives were to assess the status of p16 ink4a methylation and the HPV16 E1/E2 integrity in samples in different stages of cervical diseases. METHODS Presence of HPV16 was determined by E6 type-specific polymerase chain reaction (PCR). Methylation status of the p16 ink4a promoter was assessed by methylation-specific PCR in 87 cervical specimens comprising 29 low-grade (LSIL), 41 high-grade (HSIL) lesions, and 17 cervical cancers (CC). Characterisation of E1 and E2 disruption (as an indirect indicator of the presence of episomal viral DNA) was performed by PCR amplifications. FINDINGS We observed a significantly increased trend (nptrend = 0.0320) in the proportion of methylated p16 ink4a in cervical samples during cancer development. Concomitant E1 and E2 disruptions were the most frequent pattern found in all groups: CC (76%), HSIL (54%), and LSIL (73%). No statistically significant differences between p16 ink4a methylation and E1/E2 integrity, in histological groups, was observed. MAIN CONCLUSIONS There was an increase in methylation of the p16 ink4a promoter from pre-neoplastic lesions to cancer. Additionally, a high frequency of E1/E2 disruptions in LSIL/HSIL suggested that viral DNA integration was an early event in cervical disease. Moreover, the methylation status was apparently independent of HPV16 integrity.
Abstract in English:BACKGROUND Dengue virus type 4 (DENV-4) was first reported in Brazil in 1982 and since then no more cases were detected again in Brazil until 2010, when the virus was reintroduced. Over the following years, the virus spread to several Brazilian states and resulted in about 1,400,000 dengue cases, in 2013. The largest number of cases were documented in the Southeast macro-region. OBJECTIVES To determine the phylogeography of DENV-4 Genotype IIB strains isolated during the epidemics in 2012-2013 in São Paulo, Brazil, we aimed to contextualise the contribution of viruses sampled in different localities across the overall movement of DENV-4 in Brazil. METHODS Based on the envelope gene sequences retrieved from GenBank, we employed a Bayesian phylogeographic approach to assess the spatiotemporal dynamics of DENV-4 Genotype IIB in São Paulo, Brazil. FINDINGS The dispersal dynamics of DENV-4 Genotype IIB in Brazil indicated Rio de Janeiro and Mato Grosso states as the most likely routes toward São Paulo before the 2012-2013 outbreak. Likewise, Guarujá and São José do Rio Preto facilitated viral spread and transmission to other localities in the South and Southeast macro-regions in Brazil. CONCLUSIONS The spread pattern of DENV-4 Genotype IIB strains across the country supports two independent introductions of the virus in São Paulo in a short period of time. Furthermore, São Paulo appears to have played a pivotal role in the dissemination of DENV-4 to other locations in Brazil.
Abstract in English:BACKGROUND Shared traits between prokaryotes and eukaryotes are helpful in the understanding of the tree of life evolution. In bacteria and eukaryotes, it has been shown a particular organisation of tRNA genes as clusters, but this trait has not been explored in the archaea domain. OBJECTIVE Explore the occurrence of tRNA gene clusters in archaea. METHODS In-silico analyses of complete and draft archaeal genomes based on tRNA gene isotype and synteny, tRNA gene cluster content and mobilome elements. FINDINGS We demonstrated the prevalence of tRNA gene clusters in archaea. tRNA gene clusters, composed of archaeal-type tRNAs, were identified in two Archaea class, Halobacteria and Methanobacteria from Euryarchaeota supergroup. Genomic analyses also revealed evidence of the association between tRNA gene clusters to mobile genetic elements and intra-domain horizontal gene transfer. MAIN CONCLUSIONS tRNA gene cluster occurs in the three domains of life, suggesting a role of this type of tRNA gene organisation in the biology of the living organisms.
Abstract in English:BACKGROUND Schistosomiasis mansoni is a poverty-related parasitic infection that has a variety of clinical manifestations. We consider the disability and deaths caused by schistosomiasis unacceptable for a tool-ready disease. Its condition in Brazil warrants an analysis that will enable better understanding of the local health losses and contribute to the complex decision-making process. OBJECTIVE This study estimates the cost of schistosomiasis in Brazil in 2015. METHODS We conducted a cost of illness study of schistosomiasis mansoni in Brazil in 2015 based on a prevalence approach and from a societal perspective. The study included 26,499 schistosomiasis carriers, 397 hepatosplenic cases, 48 cases with the neurological form, 284 hospitalisations, and 11,368.26 years of life lost (YLL) of which 5,187 years are attributable to economically active age groups. RESULTS The total cost of schistosomiasis mansoni in Brazil was estimated to be US$ 41,7million in 2015 with 94.61% of this being indirect costs. CONCLUSIONS The economic burden of schistosomiasis mansoni in Brazil is high and results in the loss of productivity. Its persistence in Brazil is a challenge to public health and requires inter-sectorial interventions in areas such as indoor water supply, basic sanitation, and education.
Abstract in English:BACKGROUND Serological evidence of West Nile virus (WNV) infection has been reported in different regions of Brazil from equine and human hosts but the virus had never been isolated in the country. OBJECTIVES We sought to identify the viral etiology of equine encephalitis in Espírito Santo state. METHODS We performed viral culture in C6/36 cells, molecular detection of WNV genome, histopathology and immunohistochemistry from horse cerebral tissue. We also carried out sequencing, phylogenetic analysis and molecular clock. FINDINGS Histopathologic analysis from horse cerebral tissue showed injury related to encephalitis and WNV infection was confirmed by immunohistochemistry. The virus was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) from brain tissue and subsequently isolated in C6/36 cells. WNV full-length genome was sequenced showing the isolated strain belongs to lineage 1a. The molecular clock indicated that Brazilian WNV strain share the same common ancestor that were circulating in US during 2002-2005. MAIN CONCLUSIONS Here we report the first isolation of WNV in Brazil from a horse with neurologic disease, which was clustered into lineage 1a with others US WNV strains isolated in beginning of 2000’s decade.
Abstract in English:BACKGROUND Cryptococcosis is one of the most devastating fungal infections in humans. Despite the disease’s clinical importance, current therapy is based on limited antifungals that are either toxic, inefficient, unavailable worldwide, or that quickly lead to resistance. OBJECTIVES The goal of this study was to provide insight into the future of cryptococcosis treatment by describing the patent scenario in this field. METHODS We identified and analysed patent documents revealing compounds with anti-cryptococcal activity supported by experimental evidence. FINDINGS Patenting in this field has been historically low, with an overall tendency of increase since 2012. Most applications are single filings, suggesting that they do not encompass strategic inventions requiring broad protection. Research and development essentially took place in China and the United States, which also represent the main countries of protection. Both academic and corporate institutions contributed to patenting in this field. Universities are the leading actors, with the highest patent family counts. CONCLUSION The low number of patents in this field indicates that efforts to mitigate the unmet needs for cryptococcosis treatment remain insufficient. Without investment to drive research and innovation, patients will likely continue to face inadequate assistance. Given the current scenario characterised by poor funding and low interest for technological development, drug repurposing may be the best alternative for cryptococcosis treatment.
Abstract in English:BACKGROUND Studies aimed at validating canine visceral leishmaniasis diagnostic tests present heterogeneous results regarding test accuracy, partly due to divergences in reference standards used and different infection evolution periods in animals. OBJECTIVE This study aimed to evaluate the accuracy of the rapid test-dual path platform (TR-DPP) (Biomanguinhos®), EIE-Leishmaniose-Visceral-Canina-Biomanguinhos (EIE-LVC) (Biomanguinhos®), enzyme-linked immunosorbent assay (ELISA) rK39 (in-house), and the direct agglutination test (DAT-Canis) against a reference standard comprising parasitological and molecular techniques. METHODS A phase II/III validation study was carried out in sample sera from 123 predominantly asymptomatic dogs living in an area endemic for visceral leishmaniasis. FINDINGS Sixty-nine (56.1%) animals were considered infected according to the reference standard. For each test, the sensitivity and specificity, respectively, were as follows: TR-DPP, 21.74% [confidence interval (CI)95% 13.64% to 32.82%] and 92.59% (CI95% 82.45% to 97.08%); EIE-LVC, 11.59% (CI95% 5.9% to 21.25%) and 90.74% (CI95% 80.09% to 95.98%); ELISA rK39, 37.68% (CI95% 27.18% to 49.48%) and 83.33% (CI95% 71.26% to 90.98%); and DAT-Canis, 18.84% (CI95% 11.35% to 29.61%) and 96.30% (CI95% 87.46% to 98.98%). CONCLUSION We concluded that improving the sensitivity of serum testing for diagnosing asymptomatic dogs must constitute a priority in the process of developing new diagnostic tests to be used in the visceral leishmaniasis control program in Brazil.
Abstract in English:BACKGROUND The prompt diagnosis of plasmodial species for effective treatment prevents worsening of individual health and avoids transmission maintenance or even malaria reintroduction in areas where Plasmodium does not exist. Polymerase chain reaction (PCR) allows for the detection of parasites below the threshold of microscopic examination. OBJECTIVE Our aim was to develop a real-time PCR test to reduce diagnostic errors and increase efficacy. METHODS The lower limit of quantification and the linearity/analytical sensitivity to measure sensitivity or limit of detection (LoD) were determined. Intra-assay variations (repeatability) and alterations between assays, operators, and instruments (reproducibility) were also assessed to set precision. FINDINGS The linearity in SYBR™ Green and TaqMan™ systems was 106 and 102 copies and analytical sensitivity 1.13 and 1.17 copies/μL, respectively. Real-time PCR was more sensitive than conventional PCR, showing a LoD of 0.01 parasite (p)/μL. Reproducibility and repeatability (precision) were 100% for up to 0.1 p/μL in SYBR™ Green and 1 p/μL in TaqMan™ and conventional PCR. CONCLUSION Real-time PCR may replace conventional PCR in reference laboratories for P. vivax detection due to its rapidity. The TaqMan™ system is the most indicated when quantification assays are required. Performing tests in triplicate when diagnosing Plasmodium-infected-asymptomatic individuals is recommended to minimise diagnostic errors.
Abstract in English:BACKGROUND AND OBJECTIVE Brazil is responsible for a large number of Plasmodium vivax cases in America. Given the emergence of P. vivax parasites resistant to chloroquine and the effectiveness of antifolates in vivax malaria treatment together with a correlation between mutations in P. vivax dhfr and dhps genes and SP treatment failure, the point mutations in these genes were investigated. METHODS Blood samples from 54 patients experiencing vivax malaria symptomatic episodes in the Amazonian Region were investigated. Genomic DNA was extracted using a DNA extraction kit (QIAGENTM). Nested polymerase chain reaction (PCR) amplification was carried out followed by Sanger sequencing to detect single nucleotide polymorphisms (SNPs). FINDINGS All tested isolates showed non-synonymous mutations in pvdhfr gene: 117N (54/54, 100%) and 58R (25/54, 46%). Double mutant allele 58R/117N (FRTNI, 28%) was the most frequent followed by triple mutant alleles (58R/117N/173L, FRTNL, 11%; 58R/61M/117N, FRMNI, 5% 117N/173L, FSTNL, 4%) and quadruple mutant allele (58R/61M/117N/173L, FRMNL, 2%). A single mutation was observed at codon C383G in pvdhps gene (SGKAV, 48%). CONCLUSION No evidence of molecular signatures associated with P. vivax resistance to SP was observed in the Brazilian samples.
Abstract in English:BACKGROUND Visceral Leishmaniasis (VL) is an infectious disease that is a significant cause of death among infants aged under 1 year and the elderly in Brazil. Serodiagnosis is a mainstay of VL elimination programs; however, it has significant limitations due to low accuracy. OBJECTIVE This study aimed to evaluate three recombinant Leishmania infantum proteins (rFc, rC9, and rA2) selected from previous proteomics and genomics analyses to develop enzyme-linked immunosorbent assay (ELISA) and immunochromatographic tests (ICT) for the serodiagnosis of human VL (HVL) and canine VL (CVL). METHODS A total of 186 human (70 L. infantum-infected symptomatic, 20 other disease-infected, and 96 healthy) and 185 canine (82 L. infantum-infected symptomatic, 27 L. infantum-infected asymptomatic, and 76 healthy) sera samples were used for antibody detection. FINDINGS Of the three proteins, rA2 (91.5% sensitivity and 87% specificity) and rC9 (95.7% sensitivity and 87.5% specificity) displayed the best performance in ELISA-HVL and ELISA-CVL, respectively. ICT-rA2 also displayed the best performance for HVL diagnosis (92.3% sensitivity and 88.0% specificity) and had high concordance with immunofluorescence antibody tests (IFAT), ELISA-rK39, IT-LEISH®, and ELISAEXT. ICT-rFc, ICT-rC9, and ICT-rA2 had sensitivities of 88.6%, 86.5%, and 87.0%, respectively, with specificity values of 84.0%, 92.0%, and 100%, respectively for CVL diagnosis. MAIN CONCLUSIONS The three antigens selected by us are promising candidates for VL diagnosis regardless of the test format, although the antigen combinations and test parameters may warrant further optimisation.
Abstract in English:BACKGROUND The Zika virus (ZIKV) epidemics that affected South America in 2016 raised several research questions and prompted an increase in studies in the field. The transient and low viraemia observed in the course of ZIKV infection is a challenge for viral isolation from patient serum, which leads to many laboratories around the world sharing viral strains for their studies. C6/36 cells derived from Aedes albopictus larvae are commonly used for arbovirus isolation from clinical samples and for the preparation of viral stocks. OBJECTIVES Here, we report the contamination of two widely used ZIKV strains by Brevidensovirus, here designated as mosquito densovirus (MDV). METHODS Molecular and immunological techniques were used to analyse the MDV contamination of ZIKV stocks. Also, virus passages in mammalian cell line and infecting susceptible mice were used to MDV clearance from ZIKV stocks. FINDINGS MDV contamination was confirmed by molecular and immunological techniques and likely originated from C6/36 cultures commonly used to grow viral stocks. We applied two protocols that successfully eliminated MDV contamination from ZIKV stocks, and these protocols can be widely applied in the field. As MDV does not infect vertebrate cells, we performed serial passages of contaminated stocks using a mammalian cell line and infecting susceptible mice prior to re-isolating ZIKV from the animals’ blood serum. MDV elimination was confirmed with immunostaining, polymerase chain reaction (PCR), and analysis of the mosquitoes that were allowed to feed on the infected mice. MAIN CONCLUSIONS Since the putative impact of viral contaminants in ZIKV strains generally used for research purposes is unknown, researchers working in the field must be aware of potential contaminants and test viral stocks to certify sample purity.
Abstract in English:BACKGROUND Rifamycins are a group of antibiotics mainly used in the treatment of tuberculosis (TB), however they interact with antiretroviral therapy (ART). Rifabutin allows more regimens options for concomitant imunodeficiency virus (HIV) treatment compared to rifampicin. OBJECTIVE Compare the outcomes of TB-HIV co-infected patients who used rifampicin or rifabutin. METHODS We analysed data from a prospective cohort study at National Institute of Infectious Diseases Evandro Chagas, Rio de Janeiro (RJ), Brazil. Patients who were treated for TB and HIV with rifampicin or rifabutin, from February 2011 to September 2016 were included. FINDINGS There were 130 TB-HIV patients, of whom 102 were treated with rifampicin and 28 with rifabutin. All patients in the rifabutin-treated group and 55% of the rifampicin-treated group patients were ART-experienced. Patients treated with rifampicin had similar abandon and cure rates, interruptions in treatment due to adverse reactions, immune reconstitution inflammatory syndrome and a similar mortality rate as those treated with rifabutin. However, rifampicin-treated patients had higher CD4 counts and more frequently undetectable HIV viral load by the end of treatment (67% versus 18%, p < 0.001) compared to rifabutin-treated patients, even when only ART-experienced patients were evaluated (66,6% versus 36,3%, p = 0.039). CONCLUSIONS Patients who used rifabutin had worst immune and virological control. This group had more ART-experienced patients. New and simpler regimens are needed for patients who do not respond to previous antiretroviral therapies.
Abstract in English:BACKGROUND Owing to increased spending on pharmaceuticals since 2010, discussions about rising costs for the development of new medical technologies have been focused on the pharmaceutical industry. Computational techniques have been developed to reduce costs associated with new drug development. Among these techniques, virtual high-throughput screening (vHTS) can contribute to the drug discovery process by providing tools to search for new drugs with the ability to bind a specific molecular target. OBJECTIVES In this context, Brazilian malaria molecular targets (BraMMT) was generated to execute vHTS experiments on selected molecular targets of Plasmodium falciparum. METHODS In this study, 35 molecular targets of P. falciparum were built and evaluated against known antimalarial compounds. FINDINGS As a result, it could predict the correct molecular target of market drugs, such as artemisinin. In addition, our findings suggested a new pharmacological mechanism for quinine, which includes inhibition of falcipain-II and a potential new antimalarial candidate, clioquinol. MAIN CONCLUSIONS The BraMMT is available to perform vHTS experiments using OCTOPUS or Raccoon software to improve the search for new antimalarial compounds. It can be retrieved from www.drugdiscovery.com.br or download of Supplementary data.
Abstract in English:BACKGROUND Field testing required to license the combined measles, mumps, and rubella (MMR) vaccine must take into account the current recommendation of the vaccine in Brazil: first dose at 12 months and second dose at 15 months of age in combination with a varicella vaccine. OBJECTIVES This study aimed to evaluate the clinical consistency, immunogenicity, and reactogenicity of three batches of MMR vaccine prepared with active pharmaceutical ingredients (API) from Bio-Manguinhos, Fiocruz (MMR-Bio), and compare it to a vaccine (MMR produced by GlaxoSmithKline) with different API. METHODS This was a phase III, randomised, double-blind, non-inferiority study of the MMR-Bio administered in infants immunised at health care units in Pará, Brazil, from February 2015 to January 2016. Antibody levels were titrated by immunoenzymatic assays. Adverse events were recorded in diaries. FINDINGS Seropositivity levels after MMR-Bio were 97.6% for measles, 84.7% for mumps, and 98.0% for rubella. After the MMRV vaccine, seroconversion rates and GMT increased substantially for mumps. In contrast, approximately 35% of the children had no detectable antibodies to varicella. Systemic adverse events were more frequent than local events. CONCLUSION The demonstration of batch consistency and non-inferiority of the Bio-MMR vaccine completed the technology transfer. This is a significant technological achievement with implications for immunisation programs.
Abstract in English:BACKGROUND Opportunistic pathogenic yeast species are frequently associated with water habitats that have pollution sources of human or animal origin. Candida albicans has already been suggested as a faecal indicator microorganism for aquatic environments. OBJECTIVES The goal of this study was to investigate the occurrence of C. albicans and other opportunistic yeasts in sand and seawater samples from beaches in Brazil to assess their correlation with Escherichia coli, and to characterise the pathogenic potential of the yeast isolates. METHODS Opportunistic species (yeasts that grow at 37ºC) were isolated from sand and seawater samples from eight beaches in Brazil during the summer and the winter. Opportunistic yeast species were evaluated for their susceptibility to antifungal drugs, virulence factors, and the in vitro and in vivo biofilm formation. Strains were selected to carry out virulence tests using BALB/c mice. FINDINGS Several water samples could be classified as inappropriate for primary contact recreation in relation to E. coli densities. C. albicans was isolated in low densities. Of the 144 opportunistic yeasts evaluated, 61% displayed resistance or dose-dependent sensitivity to at least one tested drug, and 40% produced proteinase. Strains of C. albicans and Kodamaea ohmeri exhibited the highest rates of adhesion to buccal epithelial cells. All the C. albicans strains that were tested were able to undergo morphogenesis and form a biofilm on catheter fragments in both in vitro and in vivo experiments. It was possible to confirm the pathogenic potential of three of these strains during the disseminated infection test. MAIN CONCLUSIONS The identification of opportunistic yeast species in seawater and sand samples from Brazilian beaches suggest a potential risk to the health of people who use these environments for recreational purposes.
Abstract in English:BACKGROUND Nicotinamide adenine dinucleotide (NAD) plays a central role in energy metabolism and integrates cellular metabolism with signalling and gene expression. NAD biosynthesis depends on the enzyme nicotinamide/nicotinate mononucleotide adenylyltransferase (NMNAT; EC: 220.127.116.11/18), in which converge the de novo and salvage pathways. OBJECTIVE The purpose of this study was to analyse the protein-protein interactions (PPI) of NMNAT of Leishmania braziliensis (LbNMNAT) in promastigotes. METHODS Transgenic lines of L. braziliensis promastigotes were established by transfection with the pSP72αneoαLbNMNAT-GFP vector. Soluble protein extracts were prepared, co-immunoprecipitation assays were performed, and the co-immunoprecipitates were analysed by mass spectrometry. Furthermore, bioinformatics tools such as network analysis were applied to generate a PPI network. FINDINGS Proteins involved in protein folding, redox homeostasis, and translation were found to interact with the LbNMNAT protein. The PPI network indicated enzymes of the nicotinate and nicotinamide metabolic routes, as well as RNA-binding proteins, the latter being the point of convergence between our experimental and computational results. MAIN CONCLUSION We constructed a model of PPI of LbNMNAT and showed its association with proteins involved in various functions such as protein folding, redox homeostasis, translation, and NAD synthesis.
Abstract in English:BACKGROUND The longstanding application of insecticides for vector control without periodic monitoring of the population response to these chemicals can directly drive the selection of resistant populations of vector mosquitoes. Tocantins is the newest state of the Brazilian Federation. Despite a historically high number of dengue cases, studies and monitoring data concerning insecticide resistance in the state are lacking. OBJECTIVES To verify the resistance status of Aedes aegypti from 10 populations distributed throughout the state connected by rivers and roads. METHODS Between 50 and 150 ovitraps were installed in house gardens within each municipality. Collection points were established based on the importance of the towns and on geographic aspects. Dose response bioassays were performed in accordance with World Health Organization guidelines. Molecular assays were conducted to detect kdr mutations, which are related to pyrethroid resistance. FINDINGS Of the 3,200 ovitrap paddles analysed, 25.8% contained eggs, with a total of 55,687 eggs collected. With the exception of Caseara, all evaluated populations were considered to be resistant to temephos. The data showed different levels of resistance to deltamethrin among the samples. Caseara and Guaraí showed the lowest RR95 values. On average, the NaVR1 kdr allele was most frequent (40.3%), followed by NaVS (38.1%), and NaVR2 (21.6%). Palmas, the capital of the state, had the highest frequency of kdr alleles (87.5%). MAIN CONCLUSIONS With the exception of Palmas, the towns with the highest indexes (ovitrap positivity, number and density of eggs), as well with high levels of resistance and kdr alleles were located along the BR-153 road, indicating that the flow of people and cargo can contribute to the dispersion of the vector and potentially resistance. This study contributes substantially to knowledge regarding the insecticide resistance profile of Tocantins mosquito populations; the data generated via the study could facilitate the judicious use of insecticides by vector control programs.
Abstract in English:BACKGROUND This work describes a chemical study of the essential oil from leaves of Xylopia ochrantha, an endemic Annonaceae species from Brazil, and its activity against Biomphalaria species. Considering its poor solubility in aqueous medium, the essential oil was nanoemulsified to evaluate its action on controlling some mollusc species of genus Biomphalaria, snail hosts of Schistosoma mansoni that causes schistosomiasis, which mainly affects tropical and subtropical countries. OBJECTIVES The main aims of this work were to analyse the chemical composition of essential oil from X. ochrantha, and to evaluate the effect of its nanoemulsion on molluscs of genus Biomphalaria and their oviposition. METHODS Chemical analysis was performed by gas chromatography coupled to mass spectrometry. Nanoemulsions were prepared by a low energy method and characterised by particle size and polydispersity index. Biological assays evaluating the mortality of adult species of B. glabrata, B. straminea and B. tenagophila and their ovipositions upon contact with the most stable nanoemulsion during 24 and 48 h were performed. FINDINGS Chemical analysis by mass spectrometry revealed the majority presence of bicyclogermacrene and germacrene D in the essential oil. The formulation with a hydrophilic-lipophilic balance (HLB) of 9.26 was the most suitable for the oil delivery system. This nanoemulsion caused the mortality in B. tenagophila, B. straminea and B. glabarata of different sizes at levels ranging from 50 to 100% in 48 h. Additionally, the formulation could inhibit the development of deposited eggs. CONCLUSION Thus, these results suggest the use of nanoemulsified essential oil from X. ochrantha as a possible alternative in controlling some Biomphalaria species involved in the schistosomiasis cycle.
Abstract in English:BACKGROUND CD64 (FcγR1) is a high-affinity receptor for monomeric IgG1 and IgG3. Circulating neutrophils express very low amounts of CD64 on their surface. OBJECTIVES Our primary aim was to investigate the utility of neutrophil CD64 surface expression as a biomarker of active pulmonary tuberculosis (TB). We hypothesised that elevated neutrophil CD64 expression in TB infection would be associated with interferon gamma (IFN-γ) as an inducer of CD64 expression. METHODS The expression level of CD64 per neutrophil (PMN CD64 index) was quantitatively measured with flow cytometry using a Leuko64 kit in samples from patients with TB and latent TB infection (LTBI) as well as healthy controls, as part of a prospective cohort study in Brazil. FINDINGS The PMN CD64 index in patients with TB was higher than that in healthy controls and LTBI. Receiver operating characteristic curve analyses determined that the PMN CD64 index could discriminate patients with TB from those with LTBI and healthy individuals. PMN CD64 index levels returned to baseline levels after treatment. CONCLUSIONS The positive regulation of CD64 expression in circulating neutrophils of patients with active TB could represent an additional biomarker for diagnosis of active TB and could be used for monitoring individuals with LTBI before progression of TB disease.
Abstract in English:BACKGROUND The elimination of malaria depends on the blocking of transmission and of an effective treatment. In Brazil, artemisinin therapy was introduced in 1991, and here we present a performance overview during implementation outset years. METHODS It is a retrospective cohort (1991 to 2002) of patients treated in a tertiary centre of Manaus, with positive microscopic diagnosis of Plasmodium falciparum malaria, under treatment with using injectable or rectal artemisinin derivatives, and followed over 35-days to evaluate parasite clearance, death and recurrence. FINDINGS This cohort outcome resulted 97.6% (1554/1593) of patients who completed the 35-day follow-up, 0.6% (10/1593) of death and 1.8% (29/1593) of follow-up loss. All patients that died and those that presented parasitaemia recurrence had pure P. falciparum infections and received monotherapy. Considering patients who completed 35-day treatment, 98.2% (1527/1554) presented asexual parasitaemia clearance until D4 and 1.8% (27/1554) between D5-D10. It is important to highlight that had no correlation between the five treatment schemes and the sexual parasite clearance. Finally, it is noteworthy that we were able to observe also gametocytes carriage during all follow-up (D0-D35). MAIN CONCLUSIONS Artemisinin derivatives remained effective in the treatment of falciparum malaria during first 12-years of use in north area of Brazil.
Abstract in English:BACKGROUND In Brazil, the Yellow Fever virus (YFV) is endemic in the Amazon, from where it eventually expands into epidemic waves. Coastal south-eastern (SE) Brazil, which has been a YFV-free region for eight decades, has reported a severe sylvatic outbreak since 2016. The virus spread from the north toward the south of the Rio de Janeiro (RJ) state, causing 307 human cases with 105 deaths during the 2016-2017 and 2017-2018 transmission seasons. It is unclear, however, whether the YFV would persist in the coastal Atlantic Forest of RJ during subsequent transmission seasons. OBJECTIVES To conduct a real-time surveillance and assess the potential persistence of YFV in the coastal Atlantic Forest of RJ during the 2018-2019 transmission season. METHODS We combined epizootic surveillance with fast diagnostic and molecular, phylogenetic, and evolutionary analyses. FINDINGS Using this integrative strategy, we detected the first evidence of YFV re-emergence in the third transmission season (2018-2019) in a dying howler monkey from the central region of the RJ state. The YFV detected in 2019 has the molecular signature associated with the current SE YFV outbreak and exhibited a close phylogenetic relationship with the YFV lineage that circulated in the same Atlantic Forest fragment during the past seasons. This lineage circulated along the coastal side of the Serra do Mar mountain chain, and its evolution seems to be mainly driven by genetic drift. The potential bridge vector Aedes albopictus was found probing on the recently dead howler monkey in the forest edge, very close to urban areas. MAIN CONCLUSIONS Collectively, our data revealed that YFV transmission persisted at the same Atlantic Forest area for at least three consecutive transmission seasons without the need of new introductions. Our real-time surveillance strategy permitted health authorities to take preventive actions within 48 h after the detection of the sick non-human primate. The local virus persistence and the proximity of the epizootic forest to urban areas reinforces the concern with regards to the risk of re-urbanisation and seasonal re-emergence of YFV, stressing the need for continuous effective surveillance and high vaccination coverage in the SE region, particularly in RJ, an important tourist location.
Abstract in English:BACKGROUND Aedes aegypti populations in Brazil have been subjected to insecticide selection pressures with variable levels and sources since 1967. Therefore, the Brazilian Ministry of Health (MoH) coordinated the activities of an Ae. aegypti insecticide resistance monitoring network (MoReNAa) from 1999 to 2012. OBJECTIVES The objective of this study was to consolidate all information available from between 1985 and 2017 regarding the resistance status and mechanisms of Brazilian Ae. aegypti populations against the main insecticide compounds used at the national level, including the larvicide temephos (an organophosphate) and the adulticide deltamethrin (a pyrethroid). METHODS Data were gathered from two sources: a bibliographic review of studies published from 1985 to 2017, and unpublished data produced by our team within the MoReNAa between 1998 and 2012. A total of 146 municipalities were included, many of which were evaluated several times, totalling 457 evaluations for temephos and 274 for deltamethrin. Insecticide resistance data from the five Brazilian regions were examined separately using annual records of both the MoH supply of insecticides to each state and the dengue incidence in each evaluated municipality. FINDINGS Ae. aegypti resistance to temephos and deltamethrin, the main larvicide and adulticide, respectively, employed against mosquitoes in Brazil for a long time, was found to be widespread in the country, although with some regional variations. Comparisons between metabolic and target-site resistance mechanisms showed that one or another of these was the main component of pesticide resistance in each studied population. MAIN CONCLUSIONS (i) A robust dataset on the assessments of the insecticide resistance of Brazilian Ae. aegypti populations performed since 1985 was made available through our study. (ii) Our findings call into question the efficacy of chemical control as the sole methodology of vector control. (iii) It is necessary to ensure that sustainable insecticide resistance monitoring is maintained as a key component of integrated vector management. (iv) Consideration of additional parameters, beyond the supply of insecticides distributed by the MoH or the diverse local dynamics of dengue incidence, is necessary to find consistent correlations with heterogeneous vector resistance profiles.
Abstract in English:BACKGROUND The outbreak of sylvatic Yellow Fever (SYF) in humans during 2016-2017 in Brazil is one of the greatest in the history of the disease. The occurrence of the disease in areas with low vaccination coverage favoured the dissemination of the disease; therefore, it is necessary to identify the areas vulnerability to the YF virus (YFV) to assist in the adoption of preventive measures. OBJECTIVE To correlate the physical-environmental elements associated with the occurrence of SYF in humans via a multicriteria analysis. METHODS For the multicriteria analysis, preponderant elements related to SYF occurrences, including soil usage and coverage, temperature, precipitation, altitude, mosquito transmitters, and non-human primate occurrence areas, were considered. The results were validated by assessing the correlation between the incidence of SYF and the vulnerable areas identified in the multicriteria analysis. RESULTS Two regions with different vulnerability to the occurrence of the disease were identified in the multicriteria analysis, with emphasis on the southern areas of the state of São Paulo northeast areas of Minas Gerais, and the entire states of Rio de Janeiro and Espírito Santo. The map of SYF vulnerability obtained in the multicriteria analysis coincides with the areas in which cases of the disease have been recorded. The regions that presented the greatest suitability were in fact the municipalities with the highest incidence. MAIN CONCLUSIONS The multicriteria analysis revealed that the elements that were used are suited for and consistent in the prediction of the areas that are vulnerable to SYF. The results obtained indicate the proximity of the areas that are most vulnerable to the disease to densely populated areas where an Aedes aegypti infestation was observed, which confers a high risk of re-urbanisation of YF.
Abstract in English:BACKGROUND Topical treatment of New World cutaneous leishmaniasis can be affected by bacterial coinfection, hyperkeratosis, and transdermal drug delivery. OBJECTIVE The aim of this work was to evaluate the therapeutic response and safety of the topical, sequential use of antiseptic, keratolytic, and pentamidine isethionate (PMD) creams (3-PACK kit) on CL-infected BALB/c mice. METHODS A 0.5% chlorhexidine solution (CGH), 10% salicylic acid (SA), and 3% or 6% PMD were used as antiseptic, keratolytic, and antileishmanial drugs, respectively. During the first seven days, antiseptic, followed by 10% SA gel and PMD cream, were applied topically. Subsequently, treatment was performed only with the antiseptic and PMD creams. Skin irritation, reduction of lesion size (mm2), and parasitic load were observed until 30 days of treatment were completed. FINDINGS The 3-PACK treatment using 6% PMD induced a complete lesion reduction in 3/6 mice and a partial reduction in 1/6 mice, with no parasites observed. In contrast, CGH and SA alone, along with the vehicle, were not effective (p < 0.05). Moderate to severe erythema was observed at the application site. MAIN CONCLUSION The topical 3-PACK using 6% PMD was 67% effective in the treatment of CL by Leishmania (Viannia) braziliensis. Currently, work is ongoing to improve PMD isethionate formulation and to determine a dose-response.
Abstract in English:BACKGROUND TcP21 is a ubiquitous secreted protein of Trypanosoma cruzi and its recombinant form (rP21) promotes parasite cell invasion and acts as a phagocytosis inducer by activating actin polymerisation in the host cell. OBJECTIVE Our goal was to evaluate if the additional supplementation of rP21 during a prime/boost/challenge scheme with T. cruzi TCC attenuated parasites could modify the well-known protective behavior conferred by these parasites. METHODS The humoral immune response was evaluated through the assessment of total anti-T. cruzi antibodies as well as IgG subtypes. IFN-γ, TNF-α and IL-10 were measured in supernatants of splenic cells stimulated with total parasite homogenate or rP21. FINDINGS Our results demonstrated that, when comparing TCC+rP21 vs. TCC vaccinated animals, the levels of IFN-γ were significantly higher in the former group, while the levels of IL-10 and TNF-α were significantly lower. Further, the measurement of parasite load after lethal challenge showed an exacerbated infection and parasite load in heart and skeletal muscle after pre-treatment with rP21, suggesting the important role of this protein during parasite natural invasion process. MAIN CONCLUSION Our results demonstrated that rP21 may have adjuvant capacity able to modify the cytokine immune profile elicited by attenuated parasites.
Abstract in English:BACKGROUND Dengue is an arthropod-borne viral disease with a majority of asymptomatic individuals and clinical manifestations varying from mild fever to severe and potentially lethal forms. An increasing number of genetic studies have outlined the association between host genetic variations and dengue severity. Genes associated to viral recognition and entry, as well as those encoding mediators of the immune response against infection are strong candidates for association studies. OBJECTIVES The aim of this study was to investigate the association between MBL2, CLEC5A, ITGB3 and CCR5 genes and dengue severity in children. METHODS A matched case-control study was conducted and 19 single nucleotide polymorphisms (SNPs) were investigated. FINDINGS No associations were observed in single SNP analysis. However, when MBL2 SNPs were combined in haplotypes, the allele rs7095891G/rs1800450C/ rs1800451C/rs4935047A/rs930509G/rs2120131G/rs2099902C was significantly associated to risk of severe dengue under α = 0.05 (aOR = 4.02; p = 0.02). A second haplotype carrying rs4935047G and rs7095891G alleles was also associated to risk (aOR = 1.91; p = 0.04). MAIN CONCLUSIONS This is the first study to demonstrate the association between MBL2 haplotypes and dengue severity in Brazilians including adjustment for genetic ancestry. These results reinforce the role of mannose binding lectin in immune response to DENV.
Abstract in English:BACKGROUND Despite a highly efficacious vaccine, yellow fever (YF) is still a major threat in developing countries and a cause of outbreaks. In 2018, the Brazilian state of São Paulo witnessed a new YF outbreak in areas where the virus has not been detected before. OBJECTIVE The aim is to describe the clinical and laboratorial characteristics of severe cases of YF, evaluate viral to determine markers associated with fatal outcome. METHODS Acute severe YF cases (n = 62) were admitted to the Intensive Care Unit of a reference hospital and submitted to routine laboratorial evaluation on admission. YFV-RNA was detected in serum and urine by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and then sequenced. Patients were classified in two groups: survival or death. FINDINGS In the univariate analysis the following variables were associated with outcome: alanin aminotransferase (ALT), aspartat aminotransferase (AST), AST/ALT ratio, total bilirubin (TB), chronic kidney disease epidemiology collaboration (CKD-EPI), ammonia, lipase, factor V, international normalised ratio (INR), lactate and bicarbonate. Logistic regression model showed two independent variables associated with death: lipase [odds ratio (OR) 1.018, 95% confidence interval (CI) 1.007 to 1.030, p = 0.002], and factor V (OR -0.955, 95% CI 0.929 to 0.982, p = 0.001). The estimated lipase and factor V cut-off values that maximised sensitivity and specificity for death prediction were 147.5 U/L [area under the curve (AUC) = 0.879], and 56.5% (AUC = 0.913). MAIN CONCLUSIONS YF acute severe cases show a generalised involvement of different organs (liver, spleen, heart, kidneys, intestines and pancreas), and different parameters were related to outcome. Factor V and lipase are independent variables associated with death, reinforcing the importance of hemorrhagic events due to fulminant liver failure and pointing to pancreatitis as a relevant event in the outcome of the disease.
Abstract in English:BACKGROUND Polymyxins are currently used as a “last-line” treatment for multidrug-resistant Gram-negative infections. OBJECTIVES To identify the major mechanisms of resistance to polymyxin and compare the genetic similarity between multi-drug resistant Klebsiella pneumoniae strains recovered from inpatients of public hospitals in the Mid-West of Brazil. METHODS 97 carbapenems non-susceptible K. pneumoniae were studied. β-lactamases (bla OXA-48, bla KPC, bla NDM, bla CTX-M, bla SHV, bla TEM, bla IMP, bla VIM) and mcr-1 to mcr-5 genes were investigated by polymerase chain reaction (PCR). Mutations in chromosomal genes (pmrA, pmrB, phoP, phoQ, and mgrB) were screened by PCR and DNA sequencing. Clonal relatedness was established by using pulsed-field gel electrophoresis and multilocus sequence typing. FINDINGS K. pneumoniae isolates harbored bla KPC (93.3%), bla SHV (86.6%), bla TEM (80.0%), bla CTX-M (60%) genes. Of 15 K. pneumoniae resistant to polymyxin B the authors identified deleterious mutations in pmrB gene, mainly in T157P. None K. pneumoniae presented mcr gene variants. Genetic polymorphism analyses revealed 12 different pulsotypes. MAIN CONCLUSIONS Deleterious mutations in pmrB gene is the main chromosomal target for induction of polymyxin resistance in carbapenem-resistant K. pneumoniae in public hospitals in the Mid-West of Brazil.
Abstract in English:BACKGROUND Currently, there is an increasing global interest for the study of how infectious diseases could be linked to climate and weather variability. The Chagas disease was described in 1909 by Carlos Chagas, and is caused by the flagellate protozoan Trypanosoma cruzi. The Chagas disease is considered one of the biggest concerns in public health in Latin America. In Chile, the main vectors involved in the transmission of T. cruzi are arthropods of the Triatominae subfamily. Moreover, another main transmission way is through of vectors by fecal-urine way, however, oral way also has been described among others transmission form. OBJECTIVES In order to get understand outbreaks of Chagas-disease, we search for possible relationships between the frequency of cases in the Chilean population and atmospheric oscillations. METHODS We explored the two most important atmospheric oscillations in the Southern Hemisphere: southern oscillation index (SOI) and Antarctic oscillation (AAO), during the available years with official data. Because the number of migrant people born outside from Chile increasing significantively between 2014 and 2018, we used for the analysis two different periods from data available official data: (i) 2001 to 2014, (ii) 2001 to 2017. FINDINGS For both periods we observed a significant and positive relation between AAO one year before. However, for the 2001 to 2014 period positive SOI one year before, which is related with La Niña phases, was the more important variable. MAIN CONCLUSIONS The Chagas disease frequency per year in Chile was found to depend mainly on SOI in previous year, whose values can be determined one year in advance. Therefore, it is possible to partially forecast annual frequency patterns. This could have important applications in public health strategies and for allocating resources for the management of the disease.
Abstract in English:BACKGROUND The multidrug resistance (MDR) phenotype is frequently observed in Acinetobacter baumannii, the most clinically relevant pathogenic species of its genus; recently, other species belonging to the A. calcoaceticus-A. baumannii complex have emerged as important MDR nosocomial pathogens. OBJECTIVES The present study aimed to verify the occurrence of metallo-β-lactamase genes among distinct Acinetobacter species in a hospital located in the Brazilian Amazon Region. METHODS Antimicrobial susceptibility profiles were determined by broth microdilution. The genetic relationships among these isolates were assessed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Pyrosequencing reads of plasmids carrying the bla NDM-1 gene were generated using the Ion Torrent™ platform sequencing. FINDINGS A total of six isolates carried bla NDM-1: A. baumannii (n = 2), A. nosocomialis (n = 3), and A. pittii (n = 1); three carried bla IMP-1: A. baumannii, A. nosocomialis, and A. bereziniae. Resistance to colistin was observed for an NDM-1-producing A. nosocomialis isolate. Diverse PFGE patterns and sequence types were found among A. nosocomialis and A. baumannii isolates. The bla NDM-1 sequence was inserted in a Tn125 transposon, while the bla IMP-1 was found as a gene cassette of the class 1 integron In86. MAIN CONCLUSIONS To the best of our knowledge, this is the first report describing the dissemination of bla NDM-1 among distinct Acinetobacter species recovered from the same hospital in South America.
Abstract in English:BACKGROUND DNA- and proteomics-based techniques are currently used to identify a triatomine human blood meal. These methods are time consuming, require access to laboratories with sophisticated equipment, and trained personnel. OBJECTIVES We tested a rapid and specific immunochromatographic assay (that detects human blood in forensic samples) to determine if human blood was present in triatomines and their fecal excreta. METHODS We fed Triatoma rubida human blood (positive control) or mouse blood (negative control) and performed the assay on the abdominal contents and fecal excreta. Triatomine field specimens collected in and around human habitations and excreta were also tested. FINDINGS The assay was positive in triatomines fed human blood (N = 5/5) and fecal excreta from bugs known to have ingested human blood (N = 5/5). Bugs feeding on mice (N = 15/15) and their fecal excreta (N = 8/8) were negative for human blood. Human blood was detected in 47% (N = 23/49) triatomines, representing six different species, collected in the field. MAIN CONCLUSIONS The pilot study shows that this rapid and specific test may have applications in triatomine research. Further study is needed to determine the sensitivity of this assay compared to other well-established techniques, such as DNA- and proteomics-based methodologies and the assay’s application in the field.
Abstract in English:BACKGROUND Biomphalaria glabrata is the major species used for the study of schistosomiasis-related parasite-host relationships, and understanding its gene regulation may aid in this endeavor. The ubiquitin-proteasome system (UPS) performs post-translational regulation in order to maintain cellular protein homeostasis and is related to several mechanisms, including immune responses. OBJECTIVE The aims of this work were to identify and characterise the putative genes and proteins involved in UPS using bioinformatic tools and also their expression on different tissues of B. glabrata. METHODS The putative genes and proteins of UPS in B. glabrata were predicted using BLASTp and as queries reference proteins from model organism. We characterised these putative proteins using PFAM and CDD software describing the conserved domains and active sites. The phylogenetic analysis was performed using ClustalX2 and MEGA5.2. Expression evaluation was performed from 12 snail tissues using RPKM. FINDINGS 119 sequences involved in the UPS in B. glabrata were identified, which 86 have been related to the ubiquitination pathway and 33 to proteasome. In addition, the conserved domains found were associated with the ubiquitin family, UQ_con, HECT, U-box and proteasome. The main active sites were lysine and cysteine residues. Lysines are responsible and the starting point for the formation of polyubiquitin chains, while the cysteine residues of the enzymes are responsible for binding to ubiquitin. The phylogenetic analysis showed an organised distribution between the organisms and the clades of the sequences, corresponding to the tree of life of the animals, for all groups of sequences analysed. The ubiquitin sequence was the only one with a high expression profile found in all libraries, inferring its wide range of performance. MAIN CONCLUSIONS Our results show the presence, conservation and expression profile of the UPS in this mollusk, providing a basis and new knowledge for other studies involving this system. Due to the importance of the UPS and B. glabrata, this work may influence the search for new methodologies for the control of schistosomiasis.
Abstract in English:BACKGROUND Despite treatment with effective antimalarial drugs, the mortality rate is still high in severe cases of the disease, highlighting the need to find adjunct therapies that can inhibit the adhesion of Plasmodium falciparum-infected erythrocytes (Pf-iEs). OBJECTIVES In this context, we evaluated a new heparan sulfate (HS) from Nodipecten nodosus for antimalarial activity and inhibition of P. falciparum cytoadhesion and rosetting. METHODS Parasite inhibition was measured by SYBR green using a cytometer. HS was assessed in rosetting and cytoadhesion assays under static and flow conditions using Chinese hamster ovary (CHO) and human lymphatic endothelial cell (HLEC) cells expressing intercellular adhesion molecule-1 (ICAM1) and chondroitin sulfate A (CSA), respectively. FINDINGS This HS inhibited merozoite invasion similar to heparin. Moreover, mollusk HS decreased cytoadherence of P. falciparum to CSA and ICAM-1 on the surface of endothelial cells under static and flow conditions. In addition, this glycan efficiently disrupted rosettes. CONCLUSIONS These findings support a potential use for mollusk HS as adjunct therapy for severe malaria.
Abstract in English:BACKGROUND Angiostrongyliasis is caused by the nematode Angiostrongylus cantonensis and can lead to eosinophilic meningitis and meningoencephalitis in humans. The young adult worms play central pathogenic roles in the central nervous system (CNS); however, the underlying mechanism is unclear. Excretory-secretory products (ESPs) are good investigation targets for studying the relationship between a host and its parasite. OBJECTIVES We aimed to profile, identify, and characterise the proteins in the ESPs of A. cantonensis young adults. METHODS The ESPs of young adult worms were collected from culture medium after incubation ranging from 24 to 96 h. Proteomic and bioinformatics analyses were performed to characterise the ESPs. FINDINGS A total of 51 spots were identified, and the highly expressed proteins included two protein disulphide isomerases, one calreticulin, and three uncharacterised proteins. Subsequently, approximately 254 proteins were identified in the ESPs of A. cantonensis young adults via liquid chromatography-mass spectrometry (LC-MS/MS) analysis, and these were further classified according to their characteristics and biological functions. Finally, we identified the immunoreactive proteins from a reference map of ESPs from A. cantonensis young adults. Approximately eight proteins were identified, including a protein disulphide isomerase, a putative aspartic protease, annexin, and five uncharacterised proteins. The study established and identified protein reference maps for the ESPs of A. cantonensis young adults. MAIN CONCLUSIONS The identified proteins may be potential targets for the development of diagnostic or therapeutic agents for human angiostrongyliasis.
Abstract in English:BACKGROUND Only benznidazole (Bnz) (1) and nifurtimox (Nfx) (2) are licensed for the treatment of Chagas disease although their safety and efficacy profile are far from ideal. Farmanguinhos from Fiocruz has developed seven nitroimidazole compounds (4-10) analogs of megazol (3). OBJECTIVES To evaluate whether the genotoxic effect of 3 was abolished in the seven nitroimidazoles (4-10) analogs using the in vitro alkaline comet assay (CA) and the in vitro cytokinesis-block micronucleus assay (CBMN) in whole human blood cells (WHBC) and correlate this effect with their trypanocidal activity using bloodstream trypomastigote forms of Trypanosoma cruzi. METHODS The toxicity of 3-10 to WHBC in the in vitro CA was determined using the fluorescein diacetate/ethidium bromide assay. DNA damage in the in vitro CA was evaluated according to tail size in four classes (0-3) and methyl methane-sulfonate (MMS) was used as a positive control. The cytotoxicity of 3-10 to WHBC in the CBMN was measured using the cytokinesis-block proliferation index and the replication index. The number of the micronucleate cells in 2,000 binucleate cells by experimental group was determined. Mitomycin C and N-deacetyl-N-methylcolchicine were used as positive controls. FINDINGS Compound 3 showed a significant DNA strand break effect through the in vitro CA and highly significant clastogenic and/or aneugenic effect in the CBMN. Compounds 5, 6, 8, 9 and 10 showed negative results in the CBMN and positive results in the in vitro CA, while the inverse effect was observed for 4 and 7. MAIN CONCLUSIONS Compound 10 was the most promising to proceed with the development as a drug candidate in the treatment of Chagas disease showing absence of chromosomal cytogenetic damage and high activity against T. cruzi, about two times higher than 3 and the clinical drug 1.
Abstract in English:BACKGROUND The state of Rondônia (RO) is a hot spot for human cases of cutaneous leishmaniasis. Many sandfly species in RO are putative vectors of leishmaniasis. OBJECTIVES This study examines the diversity patterns and the presence of Leishmania DNA and blood meal sources of sandflies in RO. METHODS A sandfly survey was performed between 2016 and 2018 in 10 municipalities categorised into three different environment types: (i) Conservation Unit (CUN) - comprised of preserved ombrophilous forests; (ii) Forest Edge (FE) - small forest fragments; and (iii) Peridomicile (PE) - areas around dwellings. FINDINGS A total of 73 species were identified from 9,535 sandflies. The most abundant species were Psychodopygus davisi (1,741 individuals), Nyssomyia antunesi (1,397), Trichophoromyia auraensis (1,295) and Trichophoromyia ubiquitalis (1,043). Diversity was the highest in CUN, followed by the FE and PE environments. One pool of Ps. davisi tested positive for Leishmania braziliensis, reinforcing the possibility that Ps. davisi acts as a vector. The cytochrome b (cytb) sequences were used to identify three blood meal sources: Bos taurus, Homo sapiens and Tamandua tetradactyla. MAIN CONCLUSIONS Our results demonstrated that sandflies can switch between blood meal sources in differing environments. This study enhances the knowledge of the vector life cycle in RO and provides information relevant to leishmaniasis surveillance.
Abstract in English:BACKGROUND Healthcare-associated infections caused by bacteria such as Pseudomonas aeruginosa are a major public health problem worldwide. Gene regulatory networks (GRN) computationally represent interactions among regulatory genes and their targets. They are an important approach to help understand bacterial behaviour and to provide novel ways of overcoming scientific challenges, including the identification of potential therapeutic targets and the development of new drugs. OBJECTIVES The goal of this study was to reconstruct the multidrug-resistant (MDR) P. aeruginosa GRN and to analyse its topological properties. METHODS The methodology used in this study was based on gene orthology inference using the reciprocal best hit method. We used the genome of P. aeruginosa CCBH4851 as the basis of the reconstruction process. This MDR strain is representative of the sequence type 277, which was involved in an endemic outbreak in Brazil. FINDINGS We obtained a network with a larger number of regulatory genes, target genes and interactions as compared to the previously reported network. Topological analysis results are in accordance with the complex network representation of biological processes. MAIN CONCLUSIONS The properties of the network were consistent with the biological features of P. aeruginosa. To the best of our knowledge, the P. aeruginosa GRN presented here is the most complete version available to date.
Abstract in English:BACKGROUND Formation of schistosomal granulomata surrounding the ova can result in schistosomiasis-associated liver fibrosis (SSLF). The current standard of treatment is praziquantel (PZQ), which cannot effectively reverse SSLF. The role of the cannabinoid (CB) receptor family in liver fibrosis has recently been highlighted. OBJECTIVES This study aimed to assess the therapeutic effect of CB1 receptor antagonism in reversing SSLF in a murine model of Schistosoma mansoni infection. METHODS One hundred male Swiss albino mice were divided equally into five groups: healthy uninfected control (group I), infected control (group II), PZQ treated (group III), rimonabant (RIM) (SR141716, a CB1 receptor antagonist)-treated (group IV) and group V was treated with combined PZQ and RIM. Liver sections were obtained for histopathological examination, alpha-1 smooth muscle actin (α-SMA) immunostaining and assessment of CB1 receptor expression using real-time polymerase chain reaction (RT-PCR). FINDINGS The most effective reduction in fibrotic marker levels and granuloma load was achieved by combined treatment with PZQ+RIM (group V): CB1 receptor expression (H = 26.612, p < 0.001), number of α-SMA-positive cells (F = 57.086, p < 0.001), % hepatic portal fibrosis (F = 42.849, p < 0.001) and number of granulomata (F = 69.088, p < 0.001). MAIN CONCLUSIONS Combining PZQ with CB1 receptor antagonists yielded the best results in reversing SSLF. To our knowledge, this is the first study to test this regimen in S. mansoni infection.
Abstract in English:BACKGROUND Fibrosis in the peripheral nerve is the end stage of leprous neuropathy and the cause of the resulting permanent neural function impairments. Preventive measures to avoid this irreversible pathological state are a relief strategy for leprosy sufferers. OBJECTIVES The present study describes the frequency of fibrosis along with its characterisation and pathogenic development. METHODS Six-hundred-and-thirteen nerve samples were sorted from 278 neural leprosy (NL) and 335 non-leprosy neuropathy patients (ON). The total number of samples was histologically examined by routine staining methods (haematoxylin-eosin, Wade staining and Gomori’s trichrome) and fibrosis was evaluated via semi-quantitative estimation. FINDINGS Fibrosis was most frequent in the NL group (33% against 0.4% in ON) while fibrosis in association with endoneurial microfasciculation was found in 38 (41.3%) of the NL samples in the examination of semithin sections. Pericytic activation in the perivascular environment was confirmed to be the source of the fibroblasts and perineurial cells delimiting microfascicles. End-stage fibrosis in leprosy displays an arrangement of microfascicles devoid of neural components (i.e., Schwann cells and axons) lined by an intermediate phenotype of fibroblastic-perineurial cells filled with bundles of collagen fibres. MAIN CONCLUSIONS The present study underscores that fibrosis is frequently the severe end stage of neural leprosy NL pathogeny after analysing the notably distinct development of fibrosis within the neural environment.
Abstract in English:BACKGROUND The central repetitive region (CRR) of the Plasmodium vivax circumsporozoite surface protein (CSP) is composed of a repetitive sequence that is characterised by three variants: VK210, VK247 and P. vivax-like. The most important challenge in the treatment of P. vivax infection is the possibility of differential response based on the parasite genotype. OBJECTIVES To characterise the CSP variants in P. vivax isolates from individuals residing in a malaria-endemic region in Brazil and to profile these variants based on sensitivity to chloroquine and mefloquine. METHODS The CSP variants were determined by sequencing and the sensitivity of the P. vivax isolates to chloroquine and mefloquine was determined by Deli-test. FINDINGS Although five different allele sizes were amplified, the sequencing results showed that all of the isolates belonged to the VK210 variant. However, we observed substantial genetic diversity in the CRR, resulting in the identification of 10 different VK210 subtypes. The frequency of isolates that were resistant to chloroquine and mefloquine was 11.8 and 23.8%, respectively. However, we did not observe any difference in the frequency of the resistant isolates belonging to the VK210 subtypes. MAIN CONCLUSION The VK210 variant is the most frequently observed in the studied region and there is significant genetic variability in the CRR of the P. vivax CSP. Moreover, the antimalarial drug sensitivity profiles of the isolates does not seem to be related to the VK210 subtypes.
Abstract in English:BACKGROUND Dengue virus (DENV) has circulated in Brazil for over 30 years. During this time, one serotype has cyclically replaced the other, until recently, when all four distinct serotypes began to circulate together. Persistent circulation of DENV for long time periods makes sequential infections throughout a person’s life possible. After primary DENV infection, life-long immunity is developed for the infecting serotype. Since DENV and Zika virus (ZIKV) are antigenically similar, the possibility of cross-reactions has attracted attention and has been demonstrated in vitro. OBJECTIVE The aim of this study was to investigate whether immune-sera from DENV and ZIKV infected patients would cross-react in vitro with other Flaviviridae family members. METHODS Cross-reaction of the studied samples with yellow fever virus (YFV), West Nile virus (WNV), Rocio virus (ROCV), Saint Louis virus (SLEV) and Ilheus virus (ILHV) has been investigated by plaque reduction neutralisation test (PRNT) and the antibody-dependent enhancement (ADE) by flow-cytometry. FINDINGS Antibodies against ZIKV and DENV virus cross-reacted with other flaviviruses either neutralising or enhancing the infection. Thus, viral entrance into FcRFcɣRII-expressing cells were influenced by the cross-reactive antibodies. ZIKV or DENV immune sera enhanced cellular infection by WNV, ILHV, ROCV and SLEV. Finally, DENV immune sera presented higher neutralising activity for YFV and SLEV. While ZIKV immune sera neutralised WNV, ILHV and ROCV with high frequencies of positivity. MAIN CONCLUSIONS The co-circulation of those viruses in the same area represents a risk for the development of severe infections if they spread throughout the country. Successive flavivirus infections may have an impact on disease pathogenesis, as well as on the development of safe vaccine strategies.
Abstract in English:BACKGROUND Once in the pulmonary alveoli, Mycobacterium tuberculosis (Mtb) enters into contact with alveolar macrophages and dendritic cells (DCs). DCs represent the link between the innate and adaptive immune system owing to their capacity to be both a sentinel and an orchestrator of the antigen-specific immune responses against Mtb. The effect that the virulence of Mtb has on the interaction between the bacilli and human DCs has not been fully explored. OBJECTIVE To evaluate the effect of Mtb virulence on human monocyte-derived DCs. METHODS We exposed human monocyte-derived DCs to Mtb clinical strains (isolated from an epidemiological Mtb diversity study in Mexico) bearing different degrees of virulence and evaluated the capacity of DCs to internalise the bacilli, control intracellular growth, engage cell death pathways, express markers for activation and antigen presentation, and expand to stimulate autologous CD4+ T cells proliferation. FINDINGS In the case of the hypervirulent Mtb strain (Phenotype 1, strain 9005186, lineage 3), we report that DCs internalise and neutralise intracellular growth of the bacilli, undergo low rates of apoptosis, and contribute poorly to T-cell expansion, as compared to the H37Rv reference strain. In the case of the hypovirulent Mtb strain (Phenotype 4, strain 9985449, lineage 4), although DCs internalise and preclude proliferation of the bacilli, the DCs also display a high level of apoptosis, massive levels of apoptosis that prevent them from maintaining autologous CD4+ T cells in a co-culture system, as compared to H37Rv. MAIN CONCLUSIONS Our findings suggest that variability in virulence among Mtb clinical strains affects the capacity of DCs to respond to pathogenic challenge and mount an immune response against it, highlighting important parallels to studies previously done in mouse models.
Abstract in English:BACKGROUND Cardiac physiology depends on coupling and electrical and mechanical coordination through the intercalated disc. Focal adhesions offer mechanical support and signal transduction events during heart contraction-relaxation processes. Talin links integrins to the actin cytoskeleton and serves as a scaffold for the recruitment of other proteins, such as paxillin in focal adhesion formation and regulation. Chagasic cardiomyopathy is caused by infection by Trypanosoma cruzi and is a debilitating condition comprising extensive fibrosis, inflammation, cardiac hypertrophy and electrical alterations that culminate in heart failure. OBJECTIVES Since mechanotransduction coordinates heart function, we evaluated the underlying mechanism implicated in the mechanical changes, focusing especially in mechanosensitive proteins and related signalling pathways during infection of cardiac cells by T. cruzi. METHODS We investigated the effect of T. cruzi infection on the expression and distribution of talin/paxillin and associated proteins in mouse cardiomyocytes in vitro by western blotting, immunofluorescence and quantitative real-time polymerase chain reaction (qRT-PCR). FINDINGS Talin and paxillin spatial distribution in T. cruzi-infected cardiomyocytes in vitro were altered associated with a downregulation of these proteins and mRNAs levels at 72 h post-infection (hpi). Additionally, we observed an increase in the activation of the focal adhesion kinase (FAK) concomitant with increase in β-1-integrin at 24 hpi. Finally, we detected a decrease in the activation of FAK at 72 hpi in T. cruzi-infected cultures. MAIN CONCLUSION The results suggest that these changes may contribute to the mechanotransduction disturbance evidenced in chagasic cardiomyopathy.
Abstract in English:BACKGROUND In addition to the limited therapeutic arsenal and the side effects of antileishmanial agents, drug resistance hinders disease control. In Brazil, Leishmania braziliensis causes atypical (AT) tegumentary leishmaniasis lesions, frequently refractory to treatment. OBJECTIVES The main goal of this study was to characterise antimony (Sb)-resistant (SbR) L. braziliensis strains obtained from patients living in Xakriabá indigenous community, Minas Gerais, Brazil. METHODS The aquaglyceroporin 1-encoding gene (AQP1) from L. braziliensis clinical isolates was sequenced, and its function was evaluated by hypo-osmotic shock. mRNA levels of genes associated with Sb resistance were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Atomic absorption was used to measure Sb uptake. FINDINGS Although clinical isolates presented delayed recovery time in hypo-osmotic shock, AQP1 function was maintained. Isolate 340 accumulated less Sb than all other isolates, supporting the 65-fold downregulation of AQP1 mRNA levels. Both 330 and 340 isolates upregulated antimony resistance marker (ARM) 56/ARM58 and multidrug resistant protein A (MRPA); however, only ARM58 upregulation was an exclusive feature of SbR field isolates. CA7AE seemed to increase drug uptake in L. braziliensis and represented a tool to study the role of glycoconjugates in Sb transport. MAIN CONCLUSIONS There is a clear correlation between ARM56/58 upregulation and Sb resistance in AT-harbouring patients, suggesting the use of these markers as potential indicators to help the treatment choice and outcome, preventing therapeutic failure.
Abstract in English:BACKGROUND Zika virus (ZIKV) infections reported in recent epidemics have been linked to clinical complications that had never been associated with ZIKV before. Adaptive mutations could have contributed to the successful emergence of ZIKV as a global health threat to a nonimmune population. However, the causal relationships between the ZIKV genetic determinants, the pathogenesis and the rapid spread in Latin America and in the Caribbean remain widely unknown. OBJECTIVES The aim of this study was to characterise three ZIKV isolates obtained from patient samples during the 2015/2016 Brazilian epidemics. METHODS The ZIKV genomes of these strains were completely sequenced and in vitro infection kinetics experiments were carried out in cell lines and human primary cells. FINDINGS Eight nonsynonymous substitutions throughout the viral genome of the three Brazilian isolates were identified. Infection kinetics experiments were carried out with mammalian cell lines A549, Huh7.5, Vero E6 and human monocyte-derived dendritic cells (mdDCs) and insect cells (Aag2, C6/36 and AP61) and suggest that some of these mutations might be associated with distinct viral fitness. The clinical isolates also presented differences in their infectivity rates when compared to the well-established ZIKV strains (MR766 and PE243), especially in their abilities to infect mammalian cells. MAIN CONCLUSIONS Genomic analysis of three recent ZIKV isolates revealed some nonsynonymous substitutions, which could have an impact on the viral fitness in mammalian and insect cells.
Abstract in English:BACKGROUND Hepatitis delta virus (HDV) infections in hepatitis B virus (HBV) carriers are the most severe form of viral hepatitis. HDV prevalence is high in the Brazilian Amazon, but studies in other regions of the country are still scarce and often underestimated its prevalence by including a small numbers of individuals. OBJECTIVE This study aimed to determine the serological prevalence of hepatitis D, the genotypes circulating and to evaluate the associated risk factors for acquisition of HDV in Minas Gerais state, Brazil. METHODS We screened plasma samples (n = 498) from HBV chronic carriers for anti-HD antibodies using a commercial enzyme-linked immunosorbent assay (ELISA) kit. For those samples that were positive for anti-HD antibodies, we performed a reverse transcriptase (RT) nested-polymerase chain reaction (nested-PCR) in order to detect the viral genome and identify the viral genotypes circulating in the state. FINDINGS The prevalence was 6.22% (31/498). Blood transfusion was the only risk factor associated with HDV infection [risk ratio: 3.73; 95% confidence interval (CI): 1.44 to 9.65]. For 26 anti-HD positive patients, HDAg gene sequences were determined and in all patients HDV genotype 1 was found. CONCLUSIONS This study confirmed the circulation of HDV in Minas Gerais, an area previously considered non-endemic for hepatitis D in Brazil. The prevalence found in this study is much higher when compared to other studies performed in Brazil, probably because the population in our study was selected with minimal bias. Furthermore, in 26 anti-HD positive plasma samples, we were also able to detect the viral genome, indicating that these patients were experienced an active infection at the time of sample collection. These findings emphasise the importance of anti-HD testing in HBV infected individuals, which may contribute to this disease control in Brazil.
Abstract in English:BACKGROUND Calpains are proteins belonging to the multi-gene family of calcium-dependent cysteine peptidases that undergo tight on/off regulation, and uncontrolled proteolysis of calpains is associated with severe human pathologies. Calpain orthologues are expanded and diversified in the trypanosomatids genome. OBJECTIVES Here, we characterised calpains in Leishmania braziliensis, the main causative agent of cutaneous leishmaniasis in Brazil. METHODS/FINDINGS In total, 34 predicted calpain-like genes were identified. After domain structure evaluation, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) during in vitro metacyclogenesis revealed (i) five genes with enhanced expression in the procyclic stage, (ii) one augmented gene in the metacyclic stage, and (iii) one procyclic-exclusive transcript. Western blot analysis revealed that an antibody against a consensus-conserved peptide reacted with multiple calpain-like proteins, which is consistent with the multi-gene family characteristic. Flow cytometry and immunocytochemistry analyses revealed the presence of calpain-like molecules mainly in the cytoplasm, to a lesser extent in the plasma membrane, and negligible levels in the nucleus, which are all consistent with calpain localisation. Eventually, the calpain inhibitor MDL28170 was used for functional studies revealing (i) a leishmaniostatic effect, (ii) a reduction in the association index in mouse macrophages, (iii) ultra-structural alterations conceivable with autophagy, and (iv) an enhanced expression of the virulence factor GP63. CONCLUSION This report adds novel insights into the domain structure, expression, and localisation of L. braziliensis calpain-like molecules.
Abstract in English:BACKGROUND In recent years, South America has suffered the burden of continuous high impact outbreaks of dengue, chikungunya and Zika. Aedes aegypti is the main mosquito vector of these arboviruses and its control is the only solution to reduce transmission. OBJECTIVES In order to improve vector control it is essential to study mosquito population genetics in order to better estimate the population structures and the geneflow among them. METHODS We have analysed microsatellites and knockdown resistance (kdr) mutations from a trans-border region in Amazonia between the state of Amapá (Brazil) and French Guiana (overseas territory of France), to provide further knowledge on these issues. These two countries have followed distinct vector control policies since last century. For population genetic analyses we evaluated variability in 13 well-established microsatellites loci in Ae. aegypti from French Guiana (Saint Georges and Cayenne) and Brazil (Oiapoque and Macapá). The occurrence and frequency of kdr mutations in these same populations were accessed by TaqMan genotype assays for the sites 1016 (Val/Ile) and 1534 (Phe/Cys). FINDINGS We have detected high levels of gene flow between the closest cross-border samples of Saint-Georges and Oiapoque. These results suggest one common origin of re-colonisation for the populations of French Guiana and Oiapoque in Brazil, and a different source for Macapá, more similar to the other northern Brazilian populations. Genotyping of the kdr mutations revealed distinct patterns for Cayenne and Macapá associated with their different insecticide use history, and an admixture zone between these two patterns in Saint Georges and Oiapoque, in accordance with population genetic results. MAIN CONCLUSIONS The present study highlights the need for regional-local vector surveillance and transnational collaboration between neighboring countries to assess the impact of implemented vector control strategies, promote timely actions and develop preparedness plans.
Abstract in English:BACKGROUND In Brazil the implementation of the Sentinel Surveillance System of Influenza began in 2000. Central public health laboratories use reverse transcription-quantitative polymerase chain reaction (RT-qPCR) for diagnosis of respiratory viruses, but this protocol identifies only specific targets, resulted in inconclusive diagnosis for many samples. Thus, high-throughput sequencing (HTS) would be complementary method in the identification of pathogens in inconclusive samples for RT-qPCR or other specific detection protocols. OBJECTIVES This study aimed to detect unidentified viruses using HTS approach in negative samples of nasopharynx/tracheal secretions by the standard RT-qPCR collected in the Federal District, Brazil. METHODS Nucleic acids were extracted from samples collected in winter period of 2016 and subjected to HTS. The results were confirmed by the multiplex PR21 RT-qPCR, which identifies 21 respiratory pathogens. FINDINGS The main viruses identified by HTS were of families Herpesviridae, Coronaviridae, Parvoviridae and Picornaviridae, with the emphasis on rhinoviruses. The presence of respiratory viruses in the samples was confirmed by the PR21 multiplex RT-qPCR. Coronavirus, enterovirus, bocavirus and rhinovirus were found by multiplex RT-qPCR as well as by HTS analyses. MAIN CONCLUSIONS Wide virus diversity was found by different methodologies and high frequency of rhinovirus occurrence was confirmed in population in winter, showing its relevance for public health.
Abstract in English:BACKGROUND Sporotrichosis is a subcutaneous mycosis caused by dimorphic pathogenic fungi belonging to the Sporothrix genus. Pathogenic Sporothrix species typically produce melanin, which is known to be a virulence factor. OBJECTIVES The aim of this study was to perform phenotypic, genotypic, and virulence analyses of two distinct Sporothrix brasiliensis strains isolated from the same lesion on a patient from Rio de Janeiro. METHODS AND FINDINGS Genotypic analyses by partial sequencing of the calmodulin, β-tubulin, and chitin synthase genes, as well as polymerase chain reaction (PCR)-fingerprinting by T3B, M13, and GACA, showed that the isolates were very similar but not identical. Both isolates had similar phenotypic characteristics and effectively produced melanin in their yeast forms, accounting for their ability of causing disease in a murine sporotrichosis model. Remarkably, isolate B was albino in its environmental form but caused more severe disease than the pigmented A isolate. CONCLUSIONS These findings indicate that the patient was infected by two genetically and biologically distinct S. brasiliensis that vary in their production of melanin in their environmental forms. The results underscore the importance of characterizing phenotypically different isolates found in the same clinical specimen or patient.
Abstract in English:BACKGROUND Timely diagnosis is recommended by the Brazilian Visceral Leishmaniasis (VL) Surveillance and Control Program to reduce case fatality. Attempts at assessing this topic in Brazil are scarce. OBJECTIVE This study aimed to describe where, when, and how the diagnosis of VL has been performed in a Brazilian endemic setting. METHODS Data of all autochthonous cases confirmed between 2011 and 2016 (N = 81) were recorded. The care-seeking itinerary until the confirmation of VL diagnosis was assessed among 57 patients. FINDINGS The majority of VL cases (79.1%) were reported by referral hospitals. The patients mainly sought primary health care centres at the onset of symptoms. However, they had to visit seven health services on average to achieve a confirmed diagnosis. The time from the onset of symptoms to the diagnosis of VL (TD) ranged from 1-212 (median, 25) days. The TD was longer among adult patients. There was a direct correlation between the patient’s age and TD (r = 0.22; p = 0.047) and a higher occurrence of deaths due to the disease among older patients (p = 0.002). Almost all the patients (98.9%) underwent laboratory investigation, and the VL diagnosis was mainly confirmed based on clinical-laboratory criteria (92.6%). Positive results for the indirect fluorescence antibody test (22.7%) and parasitological examination plus rk39-based immunochromatographic tests (21.3%) were commonly employed. MAIN CONCLUSIONS VL diagnosis was predominantly conducted in hospitals with a long TD and wide application of serology. These findings may support measures focused on early diagnosis, including a greater involvement of the primary health care system.
Abstract in English:BACKGROUND Acinetobacter baumannii is a leading cause of nosocomial infections. This species is characterised by the presence of pandemic lineages (International Clones) that present a broad antimicrobial resistance profile. OBJECTIVE To perform the molecular epidemiology of carbapenem-resistant A. baumannii from a clinical setting in the Amazon Basin, and to characterise their antimicrobial resistance determinants. METHODS The genetic relationship of carbapenem-resistant A. baumannii were assessed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Class A, B and D β-lactamase genes were screened by polymerase chain reaction (PCR) and sequencing. The antimicrobial susceptibility profile was obtained by Disc-diffusion method and minimum inhibitory concentration (MIC) determination. FINDINGS All carbapenem-resistant A. baumannii strains belonged to three international clones, IC-1, IC-5 and IC-6, the latter recently reported by the first time in Brazil. The major determinant of carbapenem resistance in IC-1 and IC-5 strains was bla OXA-23, associated with ISAba1 and ISAba3, respectively, while IC-6 harboured the bla OXA-72. CONCLUSIONS The A. baumannii epidemiology in Brazilian Amazon Region was unknown. It was demonstrated that A. baumannii XDR international clones were responsible for nosocomial infections in Boa Vista during 2016-2018, revealing that the epidemiological scenario of A. baumannii infections in Amazon Region resembles those from the cosmopolitan regions worldwide.
Abstract in English:BACKGROUND The Yellow Fever (YF) vaccine is produced by the inoculation of embryonated chicken eggs with YF17DD virus on the ninth day of development. Full embryos are collected on the twelfth day of development for vaccine formulation. Skeletal muscle tissue is the main site where biosynthesis of viral particles occurs. OBJECTIVES This study aimed to analyse the experimental infection of skeletal muscle cells of chicken embryos by the 17DD Yellow Fever virus (YFV) in vivo and in vitro. METHODS Chicken embryos infected with YF17DD virus were analysed by immunofluorescence using confocal and super-resolution microscopes. Primary cultures of skeletal muscle cells of non-infected chicken embryos were evaluated for susceptibility and permissiveness to YF17DD virus using different protocols. This evaluation was performed based on morphological, viral titration, molecular biology, and colorimetric techniques. FINDINGS The present work phenotypically characterises embryonic chicken skeletal muscle cells as myogenic precursors expressing the Pax7 transcription factor in some cases. We demonstrated that these cells are susceptible to in vitro infection at different multiplicities of infection (MOIs), reproducing the same infection pattern observed in vivo. Furthermore, myogenic precursors and myoblasts are preferred infection targets, but establishment of infection does not depend on the presence of these cells. The peak of viral production occurred at 48 hpi, with decay occurring 72 hpi, when the cytopathic effect can be observed. MAIN CONCLUSIONS In conclusion, the primary culture of chicken skeletal muscle cells is a good model for studying muscle cells infected with YF17DD virus. This culture system displays satisfactory emulation of the in vitro phenomenon observed, contributing to our understanding of virus infection dynamics and leading to the development of alternative methods of vaccine production.
Abstract in English:BACKGROUND Severe bacterial infections initiate inadequate inflammation that leads to disseminated intravascular coagulation and death. OBJECTIVES To evaluate the influence of bacterial infection on blood viscosity and red blood cells (RBCs) morphology, and the ability of Calotropis procera proteins (CpLP) to prevent the patho-hemorheology in infected animals. METHODS Rheology of blood, atomic force microscopy measurements on specific blood elements and blood count were performed to examine changes in blood viscosity, RBCs morphology, platelets activation, and RBCs indices. FINDINGS Infected mice hold their blood rheological behaviour as compared to that of the control group. However, they presented hyperactivated platelets, RBCs at different stages of eryptosis, and variation on RBCs indices. CpLP administration in healthy animals altered blood behaviour from pseudoplastic to Bingham-like fluid. Such effect disappeared over time and by inhibiting its proteases. No alterations were observed in RBCs morphology or platelets. Treatment of infected animals with CpLP prevented the changes in RBCs indices and morphology. MAIN CONCLUSIONS The inflammatory process triggered by bacterial infection induced pathological changes in RBCs and platelets activation. Treatment of infected animals with CpLP prevented the emergence of RBCs abnormal morphology and this may have implications in the protective effect of CpLP, avoiding animal death.
Abstract in English:BACKGROUND The influence of Plasmodium spp. infection in the health of Southern brown howler monkey, Alouatta guariba clamitans, the main reservoir of malaria in the Atlantic Forest, is still unknown. OBJECTIVES The aim of this study was to investigate the positivity rate of Plasmodium infection in free-living howler monkeys in an Atlantic Forest fragment in Joinville/SC and to associate the infection with clinical, morphometrical, haematological and biochemical alterations. METHODS Molecular diagnosis of Plasmodium infection in the captured monkeys was performed by Nested-polymerase chain reaction (PCR) (18S rRNA and coxI). Haematological and biochemical parameters were compared among infected and uninfected monkeys; clinical and morphometrical parameters were also compared. FINDINGS The positivity rate of Plasmodium infection was 70% among forty captured animals, the highest reported for neotropical primates. None statistical differences were detected in the clinical parameters, and morphometric measures comparing infected and uninfected groups. The main significant alteration was the higher alanine aminotransferase (ALT) levels in infected compared to uninfected monkeys. MAIN CONCLUSIONS Therefore, Plasmodium infection in howler monkeys may causes haematological/biochemical alterations which might suggest hepatic impairment. Moreover, infection must be monitored for the eco-epidemiological surveillance of malaria in the Atlantic Forest and during primate conservation program that involves the animal movement, such as translocations.
Abstract in English:BACKGROUND Iron homeostasis contribute for the human immunodeficiency virus (HIV) pathogenesis. OBJECTIVES We assessed the iron intake pattern in antiretroviral naïve Brazilian men living with HIV correlating with clinical and nutritional parameters. METHODS The iron consumption mean was estimated according to a food frequency questionnaire (FFQ), and a 3-day food record (3dFR) submitted to the patients. HIV viral load, CD4+ T cell counts, serum iron, haematological and anthropometrics parameters were recorded. FINDINGS Fifty-one HIV-infected adult men naïve for antiretroviral therapy (ART) were enrolled. The mean age of participants was 35 (SEM ± 1.28) years old, with mean time of HIV-1 infection of 1.78 (0-16.36, min-max) years. Majority (41.18%) had complete secondary, and 21.57% had tertiary educational level. The income was around 1x (54.90%) to 2x (41.18%) minimum wage. Fifty-four percent showed normal weight, while 40% were overweight. The patients showed normal mean values of haematological parameters, and mean serum iron was 14.40 µM (SEM ± 0.83). The FFQ showed moderate correlation with the 3dFR (ρ = 0.5436, p = 0.0009), and the mean values of iron intake were 10.55(± 0.92) mg/day, recorded by FFQ, and 15.75(± 1.51) mg/day, recorded by 3dFR. The iron intake, recorded by FFQ, negatively correlated with serum iron (ρ = -0.3448, p = 0.0132), and did not have influence in the CD4+ T cell counts [e.B 0.99 (0.97-1.01, 95% confidence interval (CI), p = 0.2]. However, the iron intake showed a positive effect in HIV viral load [e.B 1.12 (1.02-1.25, 95%CI), p < 0.01]. MAIN CONCLUSIONS This study draws attention for the importance of iron intake nutritional counseling in people living with HIV. However, more studies are required to clarify the association between high iron intake and HIV infection and outcome.
Abstract in English:BACKGROUND Breastfeeding or gestation in schistosomotic mothers can cause long-term alterations in the immune response of offspring. OBJECTIVES Evaluate the expression of histone deacetylases (HDACs) (all classes), the production of cytokines by T and B lymphocytes and macrophages, and the frequency of CD4+CD25+FoxP3+-cells in adult offspring born and/or suckled by schistosomotic mothers. METHODS We harvested splenocytes from offspring born to (BIM), suckled by (SIM), or born to/suckled by (BSIM) schistosomotic mothers and animals from noninfected mothers (Control) at seven-weeks old and cultured them with/without Concanavalin A. HDAC expression was evaluated by real-time quantitative polymerase chain reaction (qPCR), and cytokines and membrane markers were evaluated by fluorescence-activated cell sorting (FACS). FINDINGS Compared to Control, BIM mice showed increased expression of HDAC9 and frequency of CD4+IL-10+-cells. The SIM group had increased expression of HDAC1, HDAC2, HDAC6, HDAC7, HDAC10, Sirt2, Sirt5, Sirt6, and Sirt7. The BSIM group only had increased HDAC10 expression. The SIM and BSIM groups exhibited decreased frequencies of CD4+IL-4+-cells and CD4+CD25+FoxP3+-cells, along with a higher frequency of CD14+IL-10+-cells and an increase in CD45R/B220+IL-10+-cells. The BSIM group also showed a high frequency of CD4+IL10+-cells. MAIN CONCLUSIONS Breastfeeding induced the expression of HDACs from various classes involved in reducing inflammatory responses. However, gestation enhanced the expression of a single HDAC and breastfeeding or gestation appears to favour multiple IL-10-dependent pathways, but not cells with a regulatory phenotype.
Abstract in English:Leishmania braziliensis is the etiological agent of American mucosal leishmaniasis, one of the most severe clinical forms of leishmaniasis. Here, we report the assembly of the L. braziliensis (M2904) genome into 35 continuous chromosomes. Also, the annotation of 8395 genes is provided. The public availability of this information will contribute to a better knowledge of this pathogen and help in the search for vaccines and novel drug targets aimed to control the disease caused by this Leishmania species.
Abstract in English:Anthropogenic environmental changes arising from settlement and agriculture include deforestation and replacement of natural vegetation by crops providing opportunities for pathogen spillover from animals to humans. This study aimed to investigate the prevalence of rodent-borne virus infections in seven rural settlements from Midwestern Brazil. Of the 466 individuals tested 12 (2.57%) were reactive for orthohantavirus and 3 (0.64%) for mammarenavirus. These rural settlers lived under unfavorable infrastructure, socioeconomic disadvantages, and unsanitary conditions, representing a risk for rodent-borne infections. Development of public policies towards the improvement of health, sanitation and awareness of rodent-borne diseases in improvised camps and settlements is imperative, in order to reduce morbidity and mortality caused by these diseases.
Abstract in English:A localized Chikungunya virus (CHIKV; East/Central/South African genotype) outbreak (50 cases, 70% laboratory-confirmed; attack rate: 5.3 confirmed cases/100 people) occurred in a Salvador, Brazil neighborhood, between Apr-Jun/2017. Highly clustered cases in space and time, mostly along a single street, highlight an increased risk of CHIKV transmission among pockets of susceptible populations. This finding underscores the need for ongoing local level surveillance for arboviral outbreaks.
Abstract in English:Human sapoviruses (HSaV) are considered important causative agents of acute gastroenteritis in humans worldwide. However, knowledge of the genetic characteristics of the whole genome of HSaV in Brazil is limited. Here we report the complete genome sequences of six HSaVs GI.2 and two GI.3 strains obtained from children with acute gastroenteritis in the Northern region of Brazil. Next generation sequencing was used to obtain the full genome and molecular characterization of the genome was performed. Phylogenetic analysis of the genome was also performed. Only one complete HSaV GI.2 genome characterization in the country precedes that of the present study. This is the first complete genome sequence of genotype GI.3 in Brazil. The data obtained in this investigation can contribute to the augmentation of the database on the molecular diversity of HSaVs strains circulating in Brazil, and to the improvement of current typing protocols.
Abstract in English:A multi-resistant strain of Vibrio parahaemolyticus was isolated from a tropical estuary in Rio de Janeiro, Brazil. Genome sequencing was conducted to establish the molecular basis of antibiotic resistance in this organism. The genetic content of this strain revealed it to be a non-virulent lineage that nevertheless possesses several antibiotic resistance determinants.
Abstract in English:The presence of tRNA array, a region with high tRNA gene number and density, has been demonstrated in Mycobacterium genus. However, a recent phylogenomic study revealed the existence of five distinct monophyletic groups (genera) within this genus. Considering this new scenario, and based on in-silico analyses, we have identified and characterised the abundance and diversity of tRNA array units within Mycobacterium, Mycolicibacterium gen. nov., Mycolicibacillus gen. nov., and Mycobacteroides gen. nov. The occurrence and prevalence of tRNA arrays among the genera belonging to Actinobacteria indicate their possible role in the organismal fitness.
Abstract in English:Anopheles bellator is a primary malaria vector in the Atlantic Forest. Partial sequences of timeless and Clock genes were used to assess the genetic differentiation of five Brazilian populations, which showed strong population structure (e.g. high F ST values and fixed differences) in all pairwise comparisons between Bahia sample and the others from Paraná, São Paulo and Rio de Janeiro states. Also, the resulting phylogenetic trees clearly grouped the sequences from Bahia in a different cluster with high bootstrap values. Among southern and southeastern populations low levels of genetic differentiation were found suggesting a general stability of the genetic structure.
Abstract in English:The leishmaniases are caused by Leishmania parasites and transmitted through the bites of phlebotomine sand flies. During parasite development inside the vector’s midgut, promastigotes move towards the stomodeal valve, a mechanism that is crucial for transmission. It has been reported that the sugar meal acquired by sand flies during feeding between bloodmeals is essential for the development and migration of parasites. We demonstrated that the distribution of Leishmania mexicana parasites was affected by the sugar meals obtained by the sand flies. Promastigote migration towards the cardia region seems to be only partially based on the stimuli provided by sugar molecules. In the absence of sugars, significant amounts of parasites developed in the hindgut. In addition, sugar meals were important for the survival of sand flies, especially during blood digestion, presumably supporting their energy requirements.
Abstract in English:The genetic information of ancient Paragonimus westermani, the oriental lung fluke infecting over 20 million people worldwide, has not been thoroughly investigated thus far. We analysed genetic markers (COI and ITS2) of P. westermani from coprolite specimens (n = 6) obtained from 15th to 18th century Korean mummies. Our results indicated that all P. westermani sequences were generally distinct from the other species of the genus Paragonimus. The sequences were clustered into three groups: Group I for East Asia; Group II for South and Southeast Asia; and Group III for India and Sri Lanka. In this study, we found that ancient P. westermani sequences in Korea belong to Group I, adding invaluable information to the existing knowledge of Paragonimus paleogenetics.
Abstract in English:Helmintex is a sensitive method used for detecting Schistosoma mansoni eggs. Here, we describe the observed frequency of six proposed criteria associated with the identification of S. mansoni eggs prepared with the Helmintex method and stained with ninhydrin. The efficacy of these criteria in classifying S. mansoni eggs when applied in various combinations was also examined. Nine observers registered the presence or absence of 6 different criteria in 100 eggs using a microscope at 100x magnification. Ninhydrin purple, which was frequently observed, was the criterion associated with the lowest inter-observer variability. At least three criteria were associated with a significantly better performance in egg identification. In conclusion, ninhydrin staining and a combination of criteria are recommended for microscope examination of faecal sediments.
Abstract in English:Hepatitis E virus (HEV), an emerging virus associated with acute hepatic disease, leads to thousands of deaths worldwide. HEV has already been reported in Brazil; however, there is a lack of epidemiological and molecular information on the genetic variability, taxonomy, and evolution of HEV. It is thus unclear whether hepatitis E is a neglected disease in Brazil or it has low relevance for public health in this country. Here, for the first time, we report the presence of HEV in Northeast Brazil. A total of 119 swine faecal samples were screened for the presence of HEV RNA using real-time polymerase chain reaction (RT-PCR) and further confirmed by conventional RT-PCR; among these, two samples were identified as positive. Molecular evolution analyses based on capsid sequences revealed that the samples had close proximities to HEV sequences belonging to genotype 3 and were genetically related to subtype 3f isolated in humans. Parsimony ancestral states analysis indicated gene flow events from HEV cross-species infection, suggesting an important role of pig hosts in viral spillover. HEV’s ability for zoonotic transmission by inter-species host switching as well as its possible adaptation to new animal species remain important issues for human health.
Abstract in English:Imported malaria is a malaria infection diagnosed outside the area where it was acquired and is induced by human migration and mobility. This retrospective study was performed based on secondary data from 2007 to 2015. In total, 736 cases of imported malaria (79.7% of 923 cases) were recorded in Rio de Janeiro state. Of the imported cases, 55.3% came from abroad, while 44.7% came from other regions of Brazil. Most cases of imported malaria in Brazil (85.5%) originated in Amazônia Legal, and Burundi (Africa) accounted for 59% of the cases from abroad. Analyses of the determinants of imported malaria in Rio de Janeiro state must be continued to understand the relationship between the origin and destination of cases.
Abstract in English:Anti-α-Gal responses may exert a protective effect in falciparum malaria. However, the biological role of such antibodies is still unknown during Plasmodium vivax infections. We investigated IgG and IgM responses to α-Gal in individuals with vivax malaria. Anti-α-Gal IgG and IgM levels were higher in these patients than in controls, but no significant correlation was found between parasitaemia and anti-α-Gal response, nor between this response and ABO blood group status. This is the first study to investigate anti-α-Gal antibodies in P. vivax-infected patients; a larger survey is necessary to achieve a better understanding of host immune response during vivax malaria.
Abstract in English:The Global Burden of Disease Study 2010 listed schistosomiasis among the leading 100 causes of death in Brazil, responsible for 3.6% of the estimated total of deaths globally. Eye and adnexa are very rarely affected by schistosomiasis mansoni, with limited documentation of ocular pathology in this setting. This short communication reports ocular histolopathological findings in a murine model of neuroschistosomiasis mansoni. Lesions were found in the bulbar conjunctiva, lacrimal gland, choroid and corneoscleral limbus.
Abstract in English:A total of 124 Neisseria gonorrhoeae isolates recovered during a 12-year period (2003-2015) from outpatients assisted at Centro de Referência e Treinamento DST/AIDS-CRT of São Paulo city, Brazil, were analysed. The following resistance rates were observed: penicillin-59.6%, ciprofloxacin-15.3%, and azithromycin-6.7%. Although reduced susceptibility to these drugs was observed since 2003, no ceftriaxone-resistant isolates were detected. Ciprofloxacin- and azithromycin non-susceptible isolates were grouped in 11 clusters. Mutations were detected in GyrA and ParC of isolates 124 and 260, and a C2611T substitution on 23S rRNA alleles was also observed in isolate 260. Both isolates belonged to ST1901/ST6210 (MSLT/NG-MAST schemes).
Abstract in English:Human enteroviruses (EVs) are associated with a wide spectrum of human diseases. Here we report the complete genome sequences of one EV-C99 strain and one E29 strain obtained from children suffering from acute gastroenteritis, without symptoms of enteroviral syndromes. This is the first report of EV-C99 in South America, and the second E29 genome described worldwide. Continuous surveillance on EVs is vital to provide further understanding of the circulation of new or rare EV serotypes in the country. The present study also highlights the capacity of EVs to remain in silent circulation in populations.
Abstract in English:Six Phlebotominae sand fly species are incriminated as biological vectors of human pathogens in Panama, but molecular corroboration is still needed. We aim at confirming the identity of Phlebotominae species documented as anthropophilic in Panama. Adult sandflies were collected from August 2010 to February 2012 in Central Panama using CDC light traps. Species confirmation was accomplished through molecular barcodes and allied sequences from GenBank. A total of 53,366 sand fly specimens representing 18 species were collected. Five species were validated molecularly as single phylogenetic clusters, but Psychodopygus thula depicted two genetically divergent lineages, which may be indicative of cryptic speciation.
Abstract in English:Human polycystic echinococcosis is a parasitic infection caused by the larval stage of Echinococcus vogeli, which occurs in rural areas of Central and South America. Until now, little information on the genetic variability of E. vogeli is available. Here, 32 samples from human-excised E. vogeli cysts had a 396-bp sequence of the mitochondrial cytochrome oxidase I (COI) gene sequenced and compared to another 17 COI sequences representing nine Echinococcus species. A Bayesian COI tree revealed that all E. vogeli sequences formed a monophyletic and well-supported clade with an E. vogeli reference sequence. The occurrence of geographically restricted E. vogeli COI haplotypes suggests retention of ancestral polymorphisms with little migration in Acre, Brazil.
Abstract in English:American visceral leishmaniasis (AVL) has two main scenarios of transmission as follows: scattered cases in rural areas and urban outbreaks. Urban AVL is in active dispersion from the northeastern border of Argentina-Paraguay-Brazil to the South. The presence of Lutzomyia longipalpis was initially reported in urban environments in the northwestern border of the country. The presence of Lu. longipalpis, environmental variables associated with its distribution, and its genetic diversity were assessed in Salvador Mazza, Argentina, on the border with Bolivia. The genetic analysis showed high haplotype diversity, low nucleotide diversity, and low nucleotide polymorphism index. We discuss the hypothesis of an expanding urban population with introgressive hybridisation of older haplogroups found in their path in natural forest or rural environments, acquiring a new adaptability to urban environments, and the possibility of changes in vector capacity.
Abstract in English:As phagocytosis is the first line of defense against malaria, we developed a phagocytosis assay with Plasmodium vivax (P. vivax) merozoites that can be applied to evaluate vaccine candidates. Briefly, after leukocyte removal with loosely packed cellulose powder in a syringe, P. vivax trophozoites matured to the merozoite-rich schizont stages in the presence of the E64 protease inhibitor. The Percoll gradient-enriched schizonts were chemically disrupted to release merozoites that were submitted to merozoite opsonin-dependent phagocytosis in two phagocytic lines with human and mouse antibodies against the N- and C-terminus of P. vivax Merozoite Surface Protein-1 (Nterm-PvMSP1 and MSP119). The resulting assay is simple and efficient for use as a routine phagocytic assay for the evaluation of merozoite stage vaccine candidates.
Abstract in English:Human bocaviruses (HBoV) are mainly associated with respiratory and gastroenteric infections. These viruses belong to the family Parvoviridae, genus Bocaparvovirus and are classified in four subtypes (HBoV1-4). Recombination and point mutation have been described as basis of parvovirus evolution. In this study three viral sequences were obtained from positives HBoV sewage samples collected in two Uruguayan cities and were characterised by different methods as recombinant strains. This recombination event was localised in the 5’ end of VP1 gene and the parental strains belonged to subtypes 3 and 4. These three Uruguayan strains are identical at the nucleotide sequences in the analysed genome region of the virus. As far as we known, this study represents the first detection of HBoV recombinants strains in the Americas.
Abstract in English:Sand fly identification is complex because it depends on the expertise of the taxonomist. The females show subtle morphological differences and the occurrence of the species complexes are usual in this taxon. Therefore, a fragment of the cytochrome c oxidase subunit I (COI) gene is used for taxon barcoding to resolve this kind of problem. This study incorporates barcode sequences, for the first time, for Evandromyia cortelezzii and Migonemyia migonei from Argentina. The nucleotide sequence divergences were estimated to generate a neighbour-joining (NJ) tree. The automatic barcode gap discovery (ABGD) approach was employed to find the barcode gaps and the operational taxonomic unit (OTU) delimitation. Other species of the subtribe were included. The frequency histogram of divergences showed a barcoding gap. The ABGD analysis identified 14 operational taxonomic units (OTUs) from 13 morphological species. Sequences of Ev. cortelezzii and Mg. migonei formed well supported clusters and were diagnosed as primary species. These sequences are useful tools for molecular identification of the sand flies of the New World.
Abstract in English:The protozoan Trypanosoma cruzi has the ability to spontaneously secrete extracellular vesicles (EVs). In this paper, T. cruzi EVs derived from epimastigote forms were evaluated during interaction with triatomine bugs Rhodnius prolixus and Triatoma infestans. T. cruzi EVs were purified and artificially offered to the insects prior to infection with epimastigote forms. No effect of EVs was detected in the parasite counts in the guts of both vectors after 49-50 days. On the other hand, pre-feeding with EVs delayed parasite migration to rectum only in the gut in R. prolixus after 21-22 days. Those data suggest a possible role of T. cruzi EVs during the earlier events of infection in the invertebrate host.
Abstract in English:Measles is a human infectious disease of global concern that is caused by the measles virus. In this study, we report the complete genome sequencing of one measles virus isolate, genotype D8, that was obtained directly from a urine sample in Boa Vista city, the capital of Roraima state in Brazil. Phylogenetic reconstruction grouped the genome described in this study with that of samples from Australia, South Korea, and Italy. To our knowledge, this is the first complete genome sequence of a wild-type measles virus reported from Latin America. Therefore, the present data strengthen the current knowledge on the molecular epidemiology of measles worldwide.
Abstract in English:Here, we report the complete genome sequence of the Aporé virus (Bunyavirales: Arenaviridae), obtained from a wild rodent Oligoryzomys mattogrossae captured in Mato Grosso do Sul state, Brazil. The genome of this virus showed strong similarity to highly pathogenic mammarenavirus from South America.
Abstract in English:We present a decentralised solution for managing scientific communication, based on distributed ledger technologies, also called blockchains. The proposed system aims to solve incentive problems displayed by traditional systems in scientific communication and publication. A minimal working model is presented, defining roles, processes, and expected results from the novel system. The proposed solution is viable, given the current status of blockchain technology, and should lead to a rethinking of current practices and their consequences for scientific communication.