Anopheles gambiae Bijagos 2022 WGS

Vector control in the Bijagós Archipelago of Guinea-Bissau relies on insecticide-treated nets. However, data on insecticide resistance is limited. This study identified deltamethrin resistance in the Anopheles gambiae sensu lato complex on Bubaque island using WHO tube tests in November 2022. Whole genome sequencing of An. gambiae sensu stricto mosquitoes identified six single nucleotide polymorphisms (SNPs) previously associated with, or putatively associated with, insecticide resistance: T791M, L995F, N1570Y, A1746S and P1874L in the vgsc gene, and L119V in the gste2 gene. Twenty additional non-synonymous SNPs were identified in insecticide-resistance associated genes. Of these, four SNPs were present at frequencies over 5% in the population, indicating that they may be under directional selection pressure and may be associated with insecticide resistance. Genome wide selection scans using Garud's H12 statistic identified two selective sweeps in the An. gambiae s.s. population; one in chromosome X and one in chromosome 2R. Both selective sweeps overlap with metabolic genes previously associated with insecticide resistance, including cyp9k1 and the cyp6aa/cyp6p gene cluster. This study presents the first phenotypic testing for deltamethrin resistance and the first whole genome sequence data for Anopheles mosquitoes from the Bijagós, contributing data of significance for vector control policy in the area. * Note that WGS data has undergone whole genome amplification prior to sequencing *