Dengue virus (DENV), an arbovirus transmitted by mosquitoes, has become a major threat to American human life, reaching approximately 23 million cases from 1980 to 2017. Brazil is among the countries most affected by this terrible viral disease, with 13.6 million cases. DENV has four different serotypes, DENV1-4, which show a broad clinical spectrum. Dengue creates a staggering epidemiological and economic burden for endemic countries. Without a specific therapy and with a commercial vaccine that presents some problems relative to its full effectiveness, initiatives to improve vector control strategies, early disease diagnostics and the development of vaccines and antiviral drugs are priorities. In this study, we present the probable origins of dengue in America and the trajectories of its spread. Overall, dengue diagnostics are costly, making the monitoring of dengue epidemiology more difficult and affecting physicians’ therapeutic decisions regarding dengue patients, especially in developing countries. This review also highlights some recent and important findings regarding dengue in Brazil and the Americas. We also summarize the existing DENV polymerase chain reaction (PCR) diagnostic tests to provide an improved reference since these tests are useful and accurate at discriminating DENV from other flaviviruses that co-circulate in the Americas. Additionally, these DENV PCR assays ensure virus serotyping, enabling epidemiologic monitoring.

The arthropod-borne Mayaro virus (MAYV) causes ‘Mayaro fever’, a disease of medical significance, primarily affecting individuals in permanent contact with forested areas in tropical South America. Recently, MAYV has attracted attention due to its likely urbanization. Currently, there are no licensed drugs against most mosquito-transmitted viruses. Here, we investigated the in vitro anti-MAYV activity of the flavonoids quercetin and its derivatives from the Brazilian shrub Bauhinia longifolia (Bong.) Steud.

Humic substances have been widely used as plant growth promoters to improve the yield of agricultural crops. However, the mechanisms underlying this effect remain unclear. Root soluble protein profiles in plants 11 days after planting and cultivated with and without humic acids (HA, 50 mg CL⁻¹), were analyzed using the label-free quantitative proteomic approach. Cultivation of maize with HA resulted in higher fresh weight of roots than in untreated plants (control). Plants treated with HA showed increased number, diameter and length of roots. In the proteomics analysis, differences were detected in the following categories: energy metabolism, cytoskeleton, cellular transport, conformation and degradation of proteins, and DNA replication. Thirty-four proteins were significantly more abundant in the seedlings treated with HA, whereas only nine proteins were abundant in the control. The effects on root architecture, such as the induction of lateral roots and biomass increase were accompanied by changes in the energy metabolism-associated proteins. The results show that the main effect of HA is protective, mainly associated with increased expression of the 2-cys peroxidase, putative VHS/GAT, and glutathione proteins. Indeed, these proteins had the highest fold-difference. Overall, these results improve our understanding of the molecular mechanisms of HA-promoted plant growth.

Citrus canker is a disease caused by Xantomonas citri subsp.citri (Xac), and has emerged as one of the major threats to the worldwide citrus crop because it affects all commercial citrus varieties, decreases the production and quality of the fruits and can spread rapidly in citrus growing areas. In this work, the first proteome of Xac was analyzed using two methodologies, two-dimensional liquid chromatography (2D LC) and tandem mass spectrometry (MS/MS).