ABSTRACT
Aedes aegypti represents one of the main vectors of at least five relevant arthropod-borne viral infections in humans (i.e., Rift Valley fever, Dengue fever, Zika, chikungunya, and yellow fever) worldwide. Ae. aegypti control strategies are mostly based on using chemical insecticides (i.e., organophosphates, pyrethroids, carbamates, and organochlorines) and reducing larval sources. Furthermore, monitoring the growth activity and mapping the geographical distribution of insecticide resistance are mandatory, as recommended by the WHO. Accordingly, we conducted a study on the possible mechanism by which Ae. aegypti develops resistance to several frequently used chemical insecticides (i.e., λ-cyhalothrin, bendiocarb, cyfluthrin, deltamethrin, malathion, and permethrin) in the city of Makassar, Sulawesi, Indonesia. The results showed the progression of resistance toward the examined insecticides in Ae. aegypti populations in Makassar. The mortality rate of Ae. aegypti was less than 90%, with the highest resistance recorded against 0.75% permethrin. The molecular evaluation of the voltage-gated sodium channel gene (VGSC) showed a significant correlation of the V1016G gene mutation in the tested 0.75% permethrin-resistant Ae. aegypti phenotypes. Nevertheless, the F1534C point mutation in the VGSC gene of Ae. aegypti did not show a significant correlation with the phenotype exhibiting insecticide resistance to 0.75% permethrin. These results indicate that Ae. aegypti mosquitoes in Makassar City have developed resistance against the frequently used insecticide permethrin, which might spread to less-populated regions of Sulawesi. Therefore, we call for further entomological monitoring of insecticide resistance not only on Sulawesi but also on other closely located islands of the Indonesian archipelago to delay the spread of Ae. aegypti insecticide resistance.