author(s)
Hegoda WKDL, Fernando HSD and De Silva BGDNK

abstract
A phenylalanine (F) to cysteine (C) substitution at position 1534 within the third domain of the NaV is associated with resistance to type I pyrethroid, permethrin, among populations of Aedes aegypti. Mosquito eggs were collected from three dengue high risk MOH areas in the Colombo district. Samples were reared to adulthood and resistance status against permethrin was determined by standard WHO susceptibility bioassays. Permethrin-resistant insects were genotyped for the F1534C mutation. All the PCR products were separated on 3.5% agarose gel and visualized by UV trans-illumination. Overall susceptibility was 58.3%, with mortality rates varying widely from 12.0% to 61.0%. Samples obtained from all three sampling sites showed high degrees of incipient resistance (<80% mortality). There was no mortality among control mosquitoes. Amplicons of approximately 90 and 110 bp correspond to alleles 1534 Phe⁺ and 1534 Cys^kdr, were obtained from all the resistant genotypes. The mutant C allele frequency varied between 0.847 and 0.543. The 1534C mutation was significantly and positively associated with permethrin resistance.