Insecticide Resistance and Occurrence of L1014F kdr Mutation in Wild Culex quinquefasciatus Populations from sub-Himalayan Region of West Bengal, India

Abstract

Introduction: Culex quinquefasciatus has been known to be the prime vector of lymphatic filariasis in the sub-Himalayan regions of West Bengal. For the control of this vector species, synthetic pyrethroids are frequently used. These vector populations eventually develop insecticide resistance due to recurrent and rampant application of these synthetic pyrethroids. Method: In this study, wild Cx. quinquefasciatus larvae are collected from various districts of the sub-Himalayan region of West Bengal and insecticide susceptibility status against 0.025% deltamethrin, 0.025% lambda-cyhalothrin, 0.25% permethrin, and 4% DDT was evaluated. The allele-specific PCR assay was performed for the detection of kdr mutation. The presence of the L1014F kdr mutation in Lambdacypermethrin-resistant Cx. quinquefasciatus populations has been further confirmed by vgsc gene sequencing. Result: The study revealed that Cx. quinquefasciatus populations from this region are highly resistant against synthetic pyrethroids and possess L1014F kdr mutation. The presence of kdr mutation in vgsc gene was a primary mode of insecticide resistance mechanism in Cx. quinquefasciatus populations. Conclusion: The present study shows occurrence L1014F kdr mutation in synthetic pyrethroid resistant Cx. quinquefasciatus populations of the sub-Himalayan region of West Bengal. The study offers current insecticide resistance profile of Cx. quinquefasciatus populations from this region. Finding the vector populations’ resistance mechanisms is essential to making the required implementations easier and reducing mistakes in vector control techniques.