Insecticide resistance selection and reversal in two strains of Aedes aegypti

Wellcome Open Research

article

Jonathan Thornton¹  Bruno Gomes¹  Constância Ayres³  Lisa Reimer¹ 

[1] Vector Biology Department, Liverpool School of Tropical Medicine;Laboratório de Bioquímica e Fisiologia de Insetos, Oswaldo Cruz Institute;Aggeu Magalhães Institute, Oswaldo Cruz Foundation

关键词: Aedes aegypti;    insecticide resistance;    mosquito;    pyrethroid;    permethrin;    temephos;    malathion;    kdr;   

DOI  :  10.12688/wellcomeopenres.15974.2

学科分类：内科医学

来源: Wellcome

【 摘 要 】

Background: Laboratory reared mosquito colonies are essential tools to understand insecticide action. However, they differ considerably from wild populations and from each other depending on their origin and rearing conditions, which makes studying the effects of specific resistance mechanisms difficult. This paper describes our methods for establishing multiple resistant strains ofAedes aegypti from two colonies as a new resource for further research on metabolic and target site resistance.Methods: Two resistant colonies ofAe. aegypti, from Cayman and Recife, were selected through 10 generations of exposure to insecticides including permethrin, malathion and temephos, to yield eight strains with different profiles of resistance due to either target site or metabolic resistance. Resistance ratios for each insecticide were calculated for the selected and unselected strains. The frequency ofkdr alleles (F1534C and V1016I) in the Cayman strains was determined using TaqMan assays. A comparative gene expression analysis among Recife strains was conducted using qPCR in larvae (CCae3A, CYP6N12, CYP6F3, CYP9M9) and adults (CCae3A, CYP6N12, CYP6BB2, CYP9J28a).Results: In the selected strain of Cayman, mortality against permethrin reduced almost to 0% andkdr became fixated by 5 generations. A similar phenotype was seen in the unselected homozygous resistant colony, whilst mortality in the susceptible homozygous colony rose to 82.9%. The Recife strains showed different responses between exposure to adulticide and larvicide, with detoxification genes in the temephos selected strain staying similar to the baseline, but a reduction in detoxification genes displayed in the other strains.Conclusions: These selected strains, with a range of insecticide resistance phenotypes and genotypes, will support further research on the effects of target-site and/or metabolic resistance mechanisms on various life-history traits, behaviours and vector competence of this important arbovirus vector.

【 授权许可】

CC BY