The V410L knockdown resistance mutation occurs in island and continental populations of Aedes aegypti in West and Central Africa.

Constância F J Ayres,Ricardo Parreira,Filomeno Fortes,Bruna Gouveia,Arlete D Troco,Silvania Leal,João Pinto,Gonçalo Seixas,Cátia Marques,Camila S Marques,Carla A Sousa,Inilça Monteiro,Sílvia Borrego,Mariangela Bonizzoni

doi:10.1371/journal.pntd.0008216

Abstract

The extensive use of insecticides for vector control has led to the development of insecticide resistance in Aedes aegypti populations on a global scale, which has significantly compromised control actions. Insecticide resistance, and its underlying mechanisms, has been investigated in several countries, mostly in South American and Asian countries. In Africa, however, studies reporting insecticide resistance are rare and data on resistance mechanisms, notably knockdown resistance (kdr) mutations, is scarce. In this study, the recently described V410L kdr mutation is reported for the first time in old world Ae. aegypti populations, namely from Angola and Madeira island. Two additional kdr mutations, V1016I and F1534C, are also reported for the first time in populations from Angola and Cape Verde. Significant associations with the resistance phenotype were found for both V410L and V1016I individually as well as for tri-locus genotypes in the Angolan population. However, no association was found in Madeira island, probably due to the presence of a complex pattern of multiple insecticide resistance mechanisms in the local Ae. aegypti population. These results suggest that populations carrying the same kdr mutations may respond differently to the same insecticide, stressing the need for complementary studies when assessing the impact of kdr resistance mechanisms in the outcome of insecticide-based control strategies.

Highlights

Vector control has been a mainstay for preventing diseases caused by arboviruses transmitted by Aedes aegypti, and for mitigating the impact of these infections on human populations
One of the pillars for the prevention of Aedes-transmitted arboviral infections has been vector control, which is primarily based on the use of chemical insecticides
Extensive use of insecticides has led to the development of insecticide resistance, undermining the sustainability of control programs

Summary

Introduction

Vector control has been a mainstay for preventing diseases caused by arboviruses transmitted by Aedes aegypti, and for mitigating the impact of these infections on human populations. Insecticide-based vector control interventions are usually intensified to reduce mosquito abundance and interrupt human-vector contact. Target site insensitivity is a major mechanism of insecticide resistance that results from point mutations in genes encoding proteins at the specific site where an insecticide binds, typically in the nervous system [1]. These mutations cause structural modifications that reduce or even completely block the binding of the insecticide. In Ae. aegypti, a total of 10 kdr mutations have been reported [1] Among these mutations, the V1016I and F1534C mutations have been extensively investigated in pyrethroid-resistant Ae. aegypti populations from Asia, South America and, to a lesser extent, Africa [2]

Methods

Results

Discussion

Conclusion