| Autor: |
Melo Costa M; Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil., Campos KB; Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasília, DF, Brazil.; Coordenação Geral de Vigilância de Aboviroses, Secretaria de Vigilância em Saúde, Ministério da Saúde, Brasília, DF, Brazil., Brito LP; Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil., Roux E; ESPACE-DEV, IRD, Université de Montpellier, Université de La Réunion, Université de la Guyane and Université des Antilles, Montpellier, France.; Laboratório Misto Internacional 'Sentinela', FIOCRUZ, UnB, IRD, Rio de Janeiro, Brazil., Melo Rodovalho C; Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil., Bellinato DF; Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil., Lima JBP; Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil., Martins AJ; Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil. ademirjr@ioc.fiocruz.br.; Laboratório Misto Internacional 'Sentinela', FIOCRUZ, UnB, IRD, Rio de Janeiro, Brazil. ademirjr@ioc.fiocruz.br.; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Universidade federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. ademirjr@ioc.fiocruz.br. |
| Abstrakt: |
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 (Na V ), 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 Na V S (1016Val + + 1534Phe + ), Na V R1 (1016Val + + 1534Cys kdr ) and Na V R2 (1016Ile kdr + 1534Cys kdr ) were consistently observed, whereas kdr alleles have rapidly spread and increased in frequency. Na V S was the less frequent allele, mostly found in Northeastern populations. The highest allelic frequencies were observed for Na V R1, especially in the North, which was fixed in one Amazonian population. The double kdr Na V R2 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 Na V R2 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. |
