Mosquitoes transmit pathogens that cause human diseases such as malaria, dengue fever, chikungunya, yellow fever, Zika fever, and filariasis. Biotechnological approaches using microorganisms have a significant potential to control mosquito populations and reduce their vector competence, making them alternatives to synthetic insecticides. Ongoing research has identified many microorganisms that can be used effectively to control mosquito populations and disease transmission. However, the successful implementation of these newly proposed approaches requires a thorough understanding of the multipronged microorganism–mosquito–pathogen–environment interactions. Although much has been achieved in discovering new entomopathogenic microorganisms, antipathogen compounds, and their mechanisms of action, only a few have been turned into viable products for mosquito control. There is a discrepancy between the number of microorganisms with the potential for the development of new insecticides and/or antipathogen products and the actual available products, highlighting the need for investments in the intersection of basic research and biotechnology.

The Aedes aegypti mosquito is the primary vector of Dengue, Chikungunya and Zika causing major problems for public health, which requires new strategies for its control, like the use of entomopathogenic microorganisms. In this study, bacteria from various Amazonian environments were isolated and tested for their pathogenicity to A. aegypti larvae. Following thermal shock to select sporulated Bacillus spp., 77 bacterial strains were isolated. Molecular identification per 16S RNA sequences revealed that the assembled strains contained several species of the genus Bacillus and one species each of Brevibacillus, Klebsiella, Serratia, Achromobacter and Brevundimonas. Among the isolated Bacillus sp. strains, 19 showed larvicidal activity against A. aegypti. Two strains of Brevibacillus halotolerans also displayed larvicidal activity. For the first time, larvicidal activity against A. aegypti was identified for a strain of Brevibacillus halotolerans. Supernatant and pellet fractions of bacterial cultures were tested separately for larvicidal activities. Eight strains contained isolated fractions resulting in at least 50% mortality when tested at a concentration of 5 mg/mL. Further studies are needed to characterize the active larvicidal metabolites produced by these microorganisms and define their mechanisms of action.

In Brazil, malaria transmission is mostly confined to the Amazon, where substantial progress has been made towards disease control in the past decade. Vector control has been historically considered a fundamental part of the main malaria control programs implemented in Brazil. However, the conventional vector-control tools have been insufficient to control or eliminate local vector populations due to the complexity of the Amazonian rainforest environment and ecological features of malaria vector species in the Amazon, especially Anopheles darlingi. Malaria elimination in Brazil and worldwide eradication will require a combination of conventional and new approaches that takes into account the regional specificities of vector populations and malaria transmission dynamics. Here we present an overview on both conventional and novel promising vector-focused tools to curb malaria transmission in the Brazilian Amazon. If well designed and employed, vector-based approaches may improve the implementation of malaria-control programs, particularly in remote or difficult-to-access areas and in regions where existing interventions have been unable to eliminate disease transmission. However, much effort still has to be put into research expanding the knowledge of neotropical malaria vectors to set the steppingstones for the optimization of conventional and development of innovative vector-control tools.

Malaria continues to affect millions of people around the world. Current control strategies have not been sufficient, and additional tools are required for malaria elimination. A promising approach is the use of bacteria from the mosquito microbiota, such as the Su_YN1 Serratia ureilytica bacterium, which is shown to strongly impair the development of P. falciparum and P. berghei in Anopheles mosquitoes. To evaluate the potential of using S. ureilytica Su_YN1 to block the Plasmodium parasite in South American vectors, we investigated its effects on mosquito fitness and survival. We found that this bacterium does not affect the longevity, blood feeding, fecundity and fertility of Anopheles aquasalis, an important South American vector. Overall, our results provide baseline support for the potential implementation of Su_YN1 for the control of malaria transmission in South America.

Fungi are a prolific source of biologically active metabolites, including a wide range of clinically important drugs. Therefore, this study aims to evaluate the antimicrobial and cytotoxic activity of secondary metabolites extracted from fungal mycelia isolated from freshwater samples in the state of Amazonas. Mycelial extracts from 12 fungal were used, extracted with MeOH/AcOEt (1:1) according to the criteria established by Souza et al. (2004). For antimicrobial activity, the extracts were tested against the pathogens Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Enterococcus feacalis, Candida albicans and C. tropicalis. To identify the minimum inhibitory dosage (MID) the microdilution method was used. To perform the cytotoxicity assay, the VERO strain (ATCC® CCL-81TM) was used. The assays were determined by the Alamar Blue method according to Ahmed et al. (1994). The tested extracts did not show antibacterial activity. Five extracts (41.7%), obtained from the fungi Aspergillus - 1283, Chrysoporther - 1169, Diaporther – 1203, Fusarium – 1085, and Trichoderma, showed antifungal activity against C. albicans. Diaporther extract (8.3%) - 1203 was active against C. tropicalis. In the cytotoxicity assay, 58.3% of the evaluated extracts showed no significant toxic effect. Five extracts, Cladosporium - 1135, Chrysoporther - 1169, Cytospora - 1098, Fusarium - 1085, and Talaromyces - 1244, showed cytotoxic potential, exhibiting viability lower than 70%. The results obtained suggest that mycelial extracts of fungi isolated from water samples from the Amazon region have potential against yeasts of medical interest. Only two of the active extracts were revealed potentially cytotoxic.

Malaria continues to affect millions of people around the world. Current control strategies have not been sufficient, and additional tools are required for malaria elimination. A promising approach is the use of bacteria from the mosquito microbiota, such as the Su_YN1 Serratia ureilytica bacterium, that was shown to strongly impair development of P. falciparum and P. berghei in Anopheles mosquitoes. To evaluate the potential of the S. ureilytica Su_YN1 bacterium as a blocker of the Plasmodium parasite in South American vectors, we investigated its effects on mosquito fitness and survival. We found that this bacterium does not affect longevity, blood feeding, fecundity and fertility of Anopheles aquasalis, an important South American vector. Overall, our results provide baseline support for the potential implementation of Su_YN1 for the control malaria transmission in South America.