This study revealed that, Cis-regulatory polymorphisms are driving the overexpression of CYP6P9a and CYP6P9b insecticide resistance genes.
Leon Mugenzi presenting his study to the jury
Evidence shows that, a major fraction of the global infectious disease burden is due to vector-borne diseases. Malaria being one of such diseases, is the number one killer and, is caused by a protozoan of the Plasmodium genus.. This study provides tools to track and assess the impact of metabolic resistance to pyrethroids. It was carried out to improve resistance management. Until today, the control of malaria in most endemic regions remains a major public health challenge. According to the World Health Organisation (WHO), resistance to pyrethroids: the main insecticide class authorised by WHO for the Impregnation of Long-lasting Insecticide Nets (LLINs) and in Indoor Residual Spraying (IRS), is ubiquitous in major malaria vectors and widespread. Finding areas without resistance to pyrethroids is becoming very rare with increasing reports of intensifying resistance in certain areas. Alternatives to pyrethroid insecticides include three other classes: organochlorines, carbamates, and organophosphates which are commonly used for IRS. Unfortunately, resistance is also gradually reported across Africa for those insecticides. This reliance on a limited number of insecticides places malaria vector populations under immense selection pressure resulting in the development and spread of insecticide resistance. Neonicotinoids is a new insecticide class which have been recently introduced to public health for IRS. For the moment, little is known if there could be cross-resistance.
This work was carry out due to the urgent need to develop suitable strategies to manage this growing resistance which has been shown recently to reduce the efficacy of pyrethroid-only LLINs. Indeed, this study provides information about the biochemical and molecular bases of this resistance, making it possible to design sensitive monitoring assays which are a critical factor for developing a successful resistance management strategy. Leon Mugenzi sought to elucidate the role of cis-regulatory changes driving the increased expression of major insecticide-resistance genes in An. funestus s.s, a major African malaria vector using comparative genomics and the luciferase reporter assays. Identification of major cis-regulatory variants was used to design the first Deoxyribonucleic Acid (DNA)-based assay to detect and track metabolic resistance in field populations of mosquitoes, thus improving the monitoring of insecticide resistance and evaluating its impact on malaria control measures. At the end of this research, he concluded that, it is urgent to develop suitable strategies to manage this growing resistance which has been proven recently to reduce the efficacy of pyrethroid-only LLINs.
