Abstract in English:BACKGROUND The World Health Organization (WHO) has classified human zoonotic tuberculosis (TB) due to Mycobacterium bovis as a neglected issue in the developing world. In a recent cross-sectional study in Brazil, three of 189 TB patients presented with a coinfection of M. bovis and M. tuberculosis and were selected as cases for this study. OBJECTIVE The aim was to evaluate risk factors (RF) for zoonotic TB in an urban area of Brazil in order to guide preventive programmes. METHODS A matched case-control study was carried out nested within a cross-sectional study. For each of the three cases, 14 age- and sex-matched controls (TB due to M. tuberculosis) were selected. FINDINGS Zoonotic potential exposures (ZE) and extrapulmonary TB (EPTB) were independently associated with zoonotic TB in multivariate analyses. CONCLUSIONS ZE by occupation and consumption of raw milk and derivative products that place individuals in direct and indirect contact with animals and their excretions/secretions increase the risk for zoonotic TB in Brazil, especially among those with EPTB. Therefore, measures such as efficient control of bovine TB, distribution of pasteurised milk and its derivative products, and the diagnosis and monitoring of zoonotic TB in humans are essential steps, especially in developing countries where bovine TB is enzootic, and further studies are necessary.
Abstract in English:BACKGROUND Malaria is responsible for 429,000 deaths per year worldwide, and more than 200 million cases were reported in 2015. Increasing parasite resistance has imposed restrictions to the currently available antimalarial drugs. Thus, the search for new, effective and safe antimalarial drugs is crucial. Heterocyclic compounds, such as dihydropyrimidinones (DHPM), synthesised via the Biginelli multicomponent reaction, as well as bicyclic compounds synthesised from DHPMs, have emerged as potential antimalarial candidates in the last few years. METHODS Thirty compounds were synthesised employing the Biginelli multicomponent reaction and subsequent one-pot substitution/cyclisation protocol; the compounds were then evaluated in vitro against chloroquine-resistant Plasmodium falciparum parasites (W2 strain). Drug cytotoxicity in baseline kidney African Green Monkey cells (BGM) was also evaluated. The most active in vitro compounds were evaluated against P. berghei parasites in mice. Additionally, we performed an in silico target fishing approach with the most active compounds, aiming to shed some light into the mechanism at a molecular level. RESULTS The synthetic route chosen was effective, leading to products with high purity and yields ranging from 10-84%. Three out of the 30 compounds tested were identified as active against the parasite and presented low toxicity. The in silico study suggested that among all the molecular targets identified by our target fishing approach, Protein Kinase 3 (PK5) and Glycogen Synthase Kinase 3β (GSK-3β) are the most likely molecular targets for the synthesised compounds. CONCLUSIONS We were able to easily obtain a collection of heterocyclic compounds with in vitro anti-P. falciparum activity that can be used as scaffolds for the design and development of new antiplasmodial drugs.
Abstract in English:BACKGROUND The diagnosis of dengue is complex. Until recently, only specialised laboratories were able to confirm dengue infection. However, this has changed with the newly available immunochromatographic rapid tests. Early diagnosis is of great interest, and point-of-care rapid tests have been increasingly used in Brazil. Most of those tests have not undergone validation in the Brazilian population. In this context, we decided to evaluate a rapid test introduced in the Federal District (FD). OBJECTIVES To estimate the accuracy and reliability of the SD Bioeasy Dengue Duo rapid test and its components to detect dengue infections in a consecutive sample of symptomatic residents in the FD, Brazil. METHODS In total, 1353 venous blood samples were collected between 2013 and 2014. Two hundred and six positive samples (cases) and 246 negative samples (non cases) were required for sensitivity and specificity estimation, respectively; for agreement evaluation, we used 401 samples. The reference standard used was a composite of MAC-ELISA, virus isolation and real-time polymerase chain reaction (RT-qPCR). The evaluation was conducted prospectively under field conditions in the public health units of the FD. FINDINGS The results for the overall accuracy of the rapid test (NS1/IgM combined) showed 76% sensitivity and 98% specificity. The sensitivity for the NS1 component (67%) was better than that for the IgM component (35%). The positive likelihood ratio was 46, and the negative likelihood ratio was 0.24. The reliability of the test (NS1/IgM combined) demonstrated crude agreement of 98% (Kappa index 0.94). MAIN CONCLUSIONS The present phase III, large-scale validation study demonstrates that the rapid test SD Bioeasy Dengue Duo has moderate sensitivity (NS1/IgM combined) and high specificity. Therefore, the test is useful in confirming the diagnosis of dengue, but not enough to rule out the diagnosis. Our results also suggest that Dengue virus (DENV) viral load estimated through the RT-qPCR and antibody level measured through the MAC-ELISA could have had a direct influence on the accuracy of the rapid test.
Abstract in English:BACKGROUND Melanin production has been associated with virulence in various pathogenic fungi, including Fonsecaea pedrosoi, the major etiological agent for chromoblastomycosis, a subcutaneous fungal disease that occurs in South America. OBJECTIVE The aim of this study was to evaluate the effects of acid-basic extracted F. pedrosoi melanin particles and fungal cell ghosts obtained by Novozym 234 treatment on their ability to activate the human complement system. METHODS The ability of melanin particles and fungal cell ghosts to activate the human complement system was evaluated by complement consumption, immunofluorescence, and enzyme-linked immunosorbent assay (ELISA). FINDINGS Unsensitised melanin particles and melanin ghosts presented complement consumption of 82.67 ± 2.08% and 96.04 ± 1.13%, respectively. Immunofluorescence assays revealed intense deposition of the C3 and C4 fragments on the surface of melanin particles and ghosts extracted from F. pedrosoi. Deposition of the C3, C4, and C5 fragments onto melanin samples and zymosan was confirmed by ELISA. Deposition of small amounts of C1q and C9 onto melanin samples and zymosan was detected by ELISA. CONCLUSION Fonsecaea pedrosoi melanin particles and fungal cell ghosts activated the complement system mainly through an alternative pathway.
Abstract in English:Dynamic S-palmitoylation of proteins is the addition of palmitic acid by zDHHC palmitoyl transferases (PATs) and depalmitoylation by palmitoyl protein thioesterases (PPTs). A putative PAT (TcPAT1) has been previously identified in Trypanosoma cruzi, the etiological agent of Chagas disease. Here we analyse other 14 putative TcPATs and 2 PPTs in the parasite genome. T. cruzi cell lines expressing TcPATs and TcPPTs plus a FLAG tag at the C terminus were produced for most enzymes, with positive detection by indirect immunofluorescence. Overexpressed TcPATs were mostly found as single spots at the parasite anterior end, while the TcPPTs were dispersed throughout the parasite body.
Abstract in English:β-lactamases, which are found in several bacterial species and environments, are the main cause of resistance to β-lactams in Gram-negative bacteria. In 2009, a protein (LRA-13) with two β-lactamase domains (one class C domain and one class D domain) was experimentally characterised, and an extended action spectrum against β-lactams consistent with two functional domains was found. Here, we present the results of searches in the non-redundant NCBI protein database that revealed the existence of a group of homologous bifunctional β-lactamases in the genomes of environmental bacteria. These findings suggest that bifunctional β-lactamases are widespread in nature; these findings also raise concern that bifunctional β-lactamases may be transferred to bacteria of clinical importance through lateral gene transfer mechanisms.
Abstract in English:In Brazil, detection of the HIV-1 sub-subtype F1 has decreased with a simultaneous increase in detection of the recombinant FB and FC forms. In previous HIV-1 env molecular epidemiology studies in Rio de Janeiro, 11.4% of the detected sequences were of the F1 sub-subtype. With the goal of re-estimating the prevalence of the HIV-1 F1 sub-subtype, we performed extended analyses of these samples by examining five genomic regions, resulting in 3.3% being confirmed as F1. Moreover, genomic analysis of 11 of the 21 samples identified as F1 confirmed that nine were F1 and two were BF1. Considering the number of samples assayed, the prevalence of F1 was quite low, which supports the use of different genomic regions for the assessment of HIV-1 classification in countries where several subtypes and recombinant forms co-circulate.
Abstract in English:The dengue virus (DENV), of the genus Flavivirus (Flaviviridae), has four antigenically distinct serotypes, of which DENV-3 is classified into five genotypes. Here, we describe the detection of DENV-3 genotype I in sera of a Brazilian patient travelling from Singapore to Rio de Janeiro, Brazil, by using multiplex real-time RT-PCR, DNA sequencing of the whole envelope protein gene, and phylogenetic analysis. The virus shares ancestry with those identified in Bali, Indonesia, in 2015. It is possible that arboviruses such as Chikungunya ECSA genotype, DENV-4 genotype I, and Zika were introduced in Brazil from other continents during the multiple international events hosted by the country over the last four years, including World Youth Day, the Soccer World Cup, and the Summer Olympics.
Abstract in English:Dengue remains an unmet public health burden. We determined risk factors for dengue in-hospital mortality in Brazil. Of 326,380 hospitalised dengue cases in 9-45-year-old individuals, there were 971 deaths. Risk of dying was 11-times higher in the presence of underlying common comorbidities (renal, infectious, pulmonary disease and diabetes), similar to the risk of dying from severe dengue and much higher with the combination. Ensuring access to integrated dengue preventative measures in individuals aged ≥ 9 years including those with comorbidities may help achieve the WHO objective of 50% reduction in mortality and 25% reduction in morbidity due to dengue by 2020.
Abstract in English:Despite being more than ten years since its introduction, global acceptance to the human papillomavirus (HPV) vaccine is still low. The immunogenetic background of the host, and HPV antigen recognition, are important in natural HPV infection, and should be taken into account in the understanding of adverse autoimmune reactions by the HPV vaccine in certain groups. There is no doubt of the benefit of vaccines in the reduction of the incidence of infectious diseases, and in the case of HPV, the prevention of persistent infection that would lead to cervical cancer. Side-effects, however, should be closely monitored and reported without any bias, to ensure that the benefits of vaccines outweigh the risks of adverse reactions. In this article we bring the attention on certain adverse effects of the vaccine against HPV that have not been well studied as they are not well defined. We also compare the different approaches on HPV vaccine policies regarding its adverse reactions in countries like Japan and Colombia, vs. the recommendations issued by the WHO.