Kdr genotyping in Aedes aegypti from Brazil on a nation-wide scale from 2017 to 2018

Monique Melo Costa (1) , Kauara Brito Campos (2, 3, 4) , Luiz Paulo Brito (5) , Emmanuel Roux (6, 7, 8) , Cynara Melo Rodovalho (5) , Diogo Fernandes Bellinato (5) , José Bento Pereira Lima (5) , Ademir Jesus Martins (5, 7, 9)

1 Laboratório de Fisiologia e Controle de Artrópodes Vetores
2 Faculdade de Medicina
3 Laboratório de Parasitologia Médica e Biologia de Vetores
4 Coordenação Geral de Vigilância de Aboviroses
5 Laboratório de Fisiologia e Controle de Artrópodes Vetores [Rio de Janeiro]
6 UMR 228 Espace-Dev, Espace pour le développement
7 LMI Sentinela [Rio de Janeiro]
8 ICICT - Institute of Scientific and Technological Communication and Information in Health / Instituto de Comunicação e Informação Científica e Tecnológica em Saúde [Rio de Janeiro]
9 INCT‑EM - Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular

Insecticide resistance is currently a threat to the control of Aedes agypti, the main vector of arboviruses in urban centers. Mutations in the voltage gated sodium channel (NaV), known as kdr (knockdown resistance), constitute an important selection mechanism for resistance against pyrethroids. In the present study, we investigated the kdr distribution for the Val1016Ile and Phe1534Cys alterations in Ae. aegypti from 123 Brazilian municipalities, based on SNP genotyping assays in over 5,500 mosquitoes. The alleles NaVS (1016Val+ + 1534Phe+), NaVR1 (1016Val+ + 1534Cyskdr) and NaVR2 (1016Ilekdr + 1534Cyskdr) were consistently observed, whereas kdr alleles have rapidly spread and increased in frequency. NaVS was the less frequent allele, mostly found in Northeastern populations. The highest allelic frequencies were observed for NaVR1, especially in the North, which was fixed in one Amazonian population. The double kdr NaVR2 was more prevalent in the Central-west and South-eastern populations. We introduce the ‘kdr index’, which revealed significant spatial patterns highlighting two to three distinct Brazilian regions. The 410L kdr mutation was additionally evaluated in 25 localities, evidencing that it generally occurs in the NaVR2 allele. This nationwide screening of a genetic mechanism for insecticide resistance is an important indication on how pyrethroid resistance in Ae. aegypti is evolving in Brazil.

Domaines: Génétique animale; Génétique des populations [q-bio.PE]; Santé publique et épidémiologie

Monique Melo Costa, Kauara Brito Campos, Luiz Paulo Brito, Emmanuel Roux, Cynara Melo Rodovalho, et al.. Kdr genotyping in Aedes aegypti from Brazil on a nation-wide scale from 2017 to 2018. Scientific Reports, 2020, 10, pp.13267. ⟨10.1038/s41598-020-70029-7⟩. ⟨hal-02914915⟩