Investigating insecticide resistance in Aedes mosquitoes after blood feeding in South Texas

Mosquitoes serve as significant vectors for the transmission of pathogens like chikunguya virus, Zika virus, and dengue virus. The widespread use of chemical insecticides, combined with the increasing spread of these vectors, have raised concerns about rising insecticide resistance. One mechanism by which mosquitoes develop resistance is metabolic resistance, which involves the overexpression of detoxification enzymes that reduces the effectiveness of insecticides. Cytochrome P450s, or CYP, are a superfamily of enzymes that have been linked to insecticide resistance. Although studies have shown resistance in south Texas, the mechanism remains unclear. Previous studies of mosquitoes from other areas have shown that environmental effects may have an influence on metabolic resistance, such as blood meal status and temperature. Blood feeding is a required behavioral component in mosquito reproduction and may influence expression of these detoxification enzymes. In this experiment, the expression of cytochrome P450 enzymes, CYP9J28 and CYP6BB2, was studied in the female Aedes aegypti mosquito after blood feeding. Mosquito susceptibility to permethrin was tested for blood fed and unfed mosquitoes. They were exposed to permethrin using the CDC bottle bioassay in three different time periods post blood feeding: 3 hours, 24 hours, and 4 days. Enzyme activity was assessed on surviving mosquitoes using qPCR. Results will be discussed. Gaining insight into how blood feeding may influence the expression of cytochrome P450s and contribute to resistance would provide knowledge that could lead to better control efforts.