First Report of F1534C kdr Mutation in Deltamethrin Resistant Aedes Albopictus From Northern Part of West Bengal, India

Abstract

West Bengal is a dengue endemic state of India with several dengue outbreaks in the recent years. Synthetic pyrethroids are the major arsenal used for the control of these vectors. The emergence of pyrethroid resistance in mosquitoes has recently been described from many parts of the world due to kdr (knock down resistance) mutations in the voltage gated sodium channel gene (vgsc). In Aedes albopictus, at least four such mutations had already been found. In this study, wild populations of Ae. albopictus were sampled from different locations of northern part of West Bengal, India. World Health Organization, 2016 recommended adult bioassay was followed throughout the experiment in order to determine susceptibility status. A total of 200 Ae. albopictus specimens including both phenotypically resistant and susceptible individuals were successfully amplified for F1534C kdr genotyping. Among them, 81% were homozygote susceptible,12.5% were heterozygote and 6.5% were homozygote resistant. Presence of F1534C mutation in pyrethroid resistant Ae. albopictus mosquitoes is the first report from India. Moreover, another novel mutation T1520I was also found to be coexisting with F1534C mutation in Ae. albopictus. This study will aid in identifying insecticide resistance mechanism and therefore, will reduce errors in vector control measures.