Bacteria-mediated modification of insecticide toxicity in the yellow fever mosquito, Aedes aegypti

Abstract

The incidence of mosquito-borne disease poses a significant threat to human and animal health throughout the world, with effective chemical control interventions limited by widespread insecticide resistance. Recent evidence suggests that gut bacteria of mosquitoes, known to be essential in nutritional homeostasis and pathogen defense, may also play a significant role in facilitating insecticide resistance. This study investigated the extent to which bacteria contribute to the general esterase and cytochrome P450 monooxygenase (P450)-mediated detoxification of the insecticides propoxur and naled, as well as the insecticidal activity of these chemistries to the yellow fever mosquito, Aedes aegypti. Experiments conducted using insecticide synergists that reduce general esterase and P450 activity demonstrate a role for both groups of enzymes in the metabolic detoxification of propoxur and naled. Furthermore, reduction of bacteria in mosquito larvae using broad-spectrum antibiotics was found to decrease the metabolic detoxification of propoxur and naled, suggesting that the bacteria themselves may be contributing to the in vivo metabolic 1 digitalcommons.unl.edu

The Midgut Microbiota of Colombian Aedes aegypti Populations with Different Levels of Resistance to the Insecticide Lambda-cyhalothrin

“…However, there are factors beyond these features that contribute to the resistant/susceptible phenotype. These include differential gene expression, copy number variation (CNVs), Single Nucleotide Polymorphisms (SNPs), epigenetic marks, and more recently, the microbiota [ 43 , 44 , 45 , 46 , 47 , 48 ].…”

“…Recently, an association was established between Ae. aegypti midgut bacteria and esterases and CYP450 activities [ 48 ]; there are midgut bacterial communities in Ae. aegypti associated with the detoxification metabolism of insecticides such as the carbamate propoxur and the organophosphate naled [ 48 ].…”

“…aegypti midgut bacteria and esterases and CYP450 activities [ 48 ]; there are midgut bacterial communities in Ae. aegypti associated with the detoxification metabolism of insecticides such as the carbamate propoxur and the organophosphate naled [ 48 ]. The elimination of bacteria in larvae with antibiotic treatment reduced esterases and CYP450 activities, consequently decreasing the metabolic detoxification of propoxur and naled [ 48 ].…”

“…aegypti associated with the detoxification metabolism of insecticides such as the carbamate propoxur and the organophosphate naled [ 48 ]. The elimination of bacteria in larvae with antibiotic treatment reduced esterases and CYP450 activities, consequently decreasing the metabolic detoxification of propoxur and naled [ 48 ]. It is not known exactly which bacterial communities are associated with these phenotypes but these results highlight the importance of the microbiota in the metabolic detoxification of carbamates and organophosphates.…”

The effects of antibiotics on the reproductive physiology targeting ovaries in the Asian tiger mosquito, Aedes albopictus

“…However, there are many kinds of antibiotics in the mosquito habitats. Antibiotics have been used to remove bacteria including Wolbachia from the mosquito (Endersby‐Harshman, Axford, & Hoffmann 2019; Nazir, Khan, & Qiu 2019; Scates, O'neal, & Anderson 2019).…”