Comparison of Amino Acid Profiles for Different Deltamethrin Resistance Statuses of Aedes albopictus (Skuse)

Abstract

Understanding the molecular aspects of the susceptibility status of mosquitoes to insecticides could help tackle the problem of insecticide resistance. One of the most important molecular profiles is the amino acids involved in the synthesis of metabolic resistance proteins. In this study, the amino acid profile is compared for three different deltamethrin resistance statuses of Aedes albopictus (Skuse), namely, the VCRU strain (susceptible in the laboratory), the Balik Pulau strain (susceptible in the field), and the Glugor strain (resistant in the field). The resistance status to the insecticide was determined using the WHO adulticide tube test. The mosquito samples were later freeze-dried and derivatized by silylation and then analyzed by gas chromatography–mass spectrometry (GC–MS). Using standardized, known concentrations of amino acids, we quantified the amino acids in three different strains. A one-way ANOVA was performed to compare the concentrations of amino acids between the strains. Of the 12 amino acids obtained from the extraction, our results showed that the susceptible strains from the laboratory and the field were not significantly different, suggesting that the profile may represent the status of susceptibility. More importantly, the resistant strain in the field had a significantly higher concentration of alanine, valine, and glycine and a significantly lower concentration of the other eight amino acids. This suggests possible metabolic adaptations related to insecticide resistance, possibly involving detoxification processes or changes in protein synthesis.