Insecticide susceptibility and detection of kdr-gene mutations in Aedes aegypti of Peshawar, Pakistan

Abstract

Dengue is an endemic disease in Peshawar, Pakistan and its primary vector is Aedes aegypti mosquito. Due to absence of vaccines and proper treatment for dengue, vector control becomes a necessary tool for disease management. Reported insecticide resistance in vectors is a serious threat to the control of dengue. This study presents the susceptibility status of Ae. aegypti to eight insecticides in district Peshawar along with one of the first attempts to screen mutations in the vector's knock down resistant gene (kdr). Local Ae. aegypti was found to be highly resistant to DDT and Deltamethrin while they were susceptible to Cyfluthrin and Bendiocarb. DNA sequencing of domains II and III of kdr-gene detected four SNPs in domain IIS6 at positions S989P and V1016G while two mutations were reported at position T1520I and F1534C in domain IIIS6. Lowest allele frequency was observed for S989P and V1016G positions while it was highest for F1534C. Among mutational combinations SSVVTICC (43%) was evidently the most predominant combination, where T1520I was heterozygous and F1534C was homozygous mutant. The study concludes instecticide resistance in local dengue population of Peshawar, Pakistan. The resistance observed is to some extent also corroborated in the molecular study of kdr gene. Findings herein can be utilized in designing dengue vector control strategies in Peshawar.