Metabolomic differentiation of amino acid profiles in adult deltamethrin-resistant Aedes albopictus (L.)

Understanding the susceptibility status of mosquitoes to insecticides is critical for effective decision making regarding the use or rotation of insecticides in control programs. In this study, we demonstrated the use of amino acid profiling for the detection of deltamethrin-resistant Aedes albopictus (L.). Mosquitoes collected in the field were first tested with WHO adulticide bioassay kits, and the amino acid profiles of the resistant mosquitoes were compared with the susceptible strain of Ae. albopictus. Samples were lyophilized and derived 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 both resistant and susceptible strains. An independent t-test was performed to compare the concentrations of each amino acid between strains. Logistic regression was then performed to assess the relationship between amino acid concentrations and susceptibility status of the mosquitoes. Our results showed that the amino acids in resistant mosquitoes differed significantly from those in susceptible mosquitoes, with the exception of serine. Further regression analysis showed that seven amino acids significantly predicted susceptibility, suggesting that they are suitable as biological indicators for rapid assessment of resistance status in field mosquitoes. Graphic abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=127 SRC="FIGDIR/small/604257v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@7c3c91org.highwire.dtl.DTLVardef@6c7ad1org.highwire.dtl.DTLVardef@1f36900org.highwire.dtl.DTLVardef@172b13d_HPS_FORMAT_FIGEXP M_FIG C_FIG Identification of deltamethrin-resistant mosquitoes based on differences in the amino acid profile: Deltamethrin-susceptible and -resistant mosquito strains were lyophilised and converted into esters by silylation, which were then analysed using a gas chromatography-mass spectrometer (GC-MS). The difference between susceptible and resistant could be classified by developing a classification model with logistic regression.