RESUMO
BACKGROUND: Mosquitoes feed on plant-derived fluids such as nectar and sap and are exposed to bioactive molecules found in this dietary source. However, the role of such molecules on mosquito vectorial capacity is unknown. Weather has been recognized as a major determinant of the spread of dengue, and plants under abiotic stress increase their production of polyphenols. RESULTS: Here, we show that including polyphenols in mosquito meals promoted the activation of AMP-dependent protein kinase (AMPK). AMPK positively regulated midgut autophagy leading to a decrease in bacterial proliferation and an increase in vector lifespan. Suppression of AMPK activity resulted in a 6-fold increase in midgut microbiota. Similarly, inhibition of polyphenol-induced autophagy induced an 8-fold increase in bacterial proliferation. Mosquitoes maintained on the polyphenol diet were readily infected by dengue virus. CONCLUSION: The present findings uncover a new direct route by which exacerbation of autophagy through activation of the AMPK pathway leads to a more efficient control of mosquito midgut microbiota and increases the average mosquito lifespan. Our results suggest for the first time that the polyphenol content and availability of the surrounding vegetation may increase the population of mosquitoes prone to infection with arboviruses.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Aedes/microbiologia , Autofagia , Bactérias/crescimento & desenvolvimento , Trato Gastrointestinal , Proteínas de Insetos/metabolismo , Insetos Vetores/microbiologia , Polifenóis/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Aedes/enzimologia , Aedes/crescimento & desenvolvimento , Aedes/metabolismo , Ração Animal/análise , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Feminino , Microbioma Gastrointestinal , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/fisiologia , Proteínas de Insetos/genética , Insetos Vetores/enzimologia , Insetos Vetores/crescimento & desenvolvimento , Insetos Vetores/metabolismo , MasculinoRESUMO
We show for the first time that the ventral diverticulum of the mosquito gut (impermeable sugar storage organ) harbors microorganisms. The gut diverticulum from newly emerged and non-fed Aedes aegypti was dissected under aseptic conditions, homogenized and plated on BHI medium. Microbial isolates were identified by sequencing of 16S rDNA for bacteria and 28S rDNA for yeast. A direct DNA extraction from Ae. aegypti gut diverticulum was also performed. The bacterial isolates were: Bacillus sp., Bacillus subtilis and Serratia sp. The latter was the predominant bacteria found in our isolations. The yeast species identified was Pichia caribbica.
Assuntos
Aedes/microbiologia , Bacillus/isolamento & purificação , Trato Gastrointestinal/microbiologia , Pichia/isolamento & purificação , Serratia/isolamento & purificação , Animais , Bacillus/genética , DNA Bacteriano/genética , DNA Ribossômico/genética , Pichia/genética , RNA Ribossômico 16S/genética , RNA Ribossômico 28S/genética , Serratia/genéticaRESUMO
Aqueous suspension of ethanol extracts of Derris (Lonchocarpus) urucu (Leguminosae), collected in the state of Amazonas, Brazil, were tested for larvicidal activity against the mosquito Aedes aegypti (Diptera:Culicidae). The aim of this study was to observe the alterations of peritrophic matrix in Ae. aegypti larvae treated with an aqueous suspension of D. urucu extract. Different concentrations of D. urucu root extract were tested against fourth instar larvae. One hundred percent mortality was observed at 150 microg/ml (LC(50) 17.6 microg/ml) 24 h following treatment. In response to D. urucu feeding, larvae excreted a large amount of amorphous feces, while control larvae did not produce feces during the assay period. Ultrastructural studies showed tha larvae fed with 150 microg/ml of D. urucu extract for 4 h have an imperfect peritrophic matrix and extensive damage of the midgut epithelium. Data indicate a protective role for the peritrophic matrix. The structural modification of the peritrophic matrix is intrinsically associated with larval mortality.
Assuntos
Aedes/efeitos dos fármacos , Fabaceae/química , Aedes/metabolismo , Aedes/ultraestrutura , Animais , Larva/efeitos dos fármacos , Larva/ultraestrutura , Microscopia Eletrônica , Extratos Vegetais/química , Extratos Vegetais/farmacologiaRESUMO
We show for the first time that the ventral diverticulum of the mosquito gut (impermeable sugar storage organ) harbors microorganisms. The gut diverticulum from newly emerged and non-fed Aedes aegypti was dissected under aseptic conditions, homogenized and plated on BHI medium. Microbial isolates were identified by sequencing of 16S rDNA for bacteria and 28S rDNA for yeast. A direct DNA extraction from Ae. aegypti gut diverticulum was also performed. The bacterial isolates were: Bacillus sp., Bacillus subtilis and Serratia sp. The latter was the predominant bacteria found in our isolations. The yeast species identified was Pichia caribbica.
Assuntos
Animais , Aedes/microbiologia , Bacillus/isolamento & purificação , Trato Gastrointestinal/microbiologia , Pichia/isolamento & purificação , Serratia/isolamento & purificação , Bacillus/genética , DNA Bacteriano/genética , DNA Ribossômico/genética , Pichia/genética , /genética , /genética , Serratia/genéticaRESUMO
Aqueous suspension of ethanol extracts of Derris (Lochocarpus) urucu (Leguminosae), collected in the state of Amazonas, Brazil, were tested for larvicidal activity against the mosquito Aedes aegypti (Diptera:Culicidae). the aim of this study was to observe the alterations of peritrophic matrix in Ae. aegypti larvae treated with an aqueous suspension of D. urucu extract. Different concentrations of D. urucu root extract were tested against fourth instar larvae. One hundred percent mortality was observed at 150 microg/ml (LC(50) 17.6 microg/ml) 24 h following treatment. In response to D. urucu feeding, larvae excreted a large amount of amorphous feces, while control larvae did not produce feces during the assay period. Ultrastructural studies showed tha larvae fed with 150 microg/ml of D. urucu extract for 4 h have an imperfect peritrophic matrix and extensive damage of the midgut epithelium. Data indicate a protective role for the peritrophic matrix. The structural modification of the peritrophic matrix is intrinsically associated with larval mortality.