Analyses of Insecticide Resistance Genes in <i>Aedes aegypti</i> and <i>Aedes albopictus</i> Mosquito Populations from Cameroon

• Main Authors: Borel Djiappi-Tchamen, Mariette Stella Nana-Ndjangwo, Konstantinos Mavridis, Abdou Talipouo, Elysée Nchoutpouen, Idene Makoudjou, Roland Bamou, Audrey Marie Paul Mayi, Parfait Awono-Ambene, Timoléon Tchuinkam, John Vontas, Christophe Antonio-Nkondjio
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Genes
• Subjects: <i>Aedes aegypti</i>; <i>Aedes albopictus</i>; insecticide resistance diagnostics; arbovirus; mechanisms; urban settings
• Online Access: https://www.mdpi.com/2073-4425/12/6/828

The emergence of insecticide resistance in <i>Aedes mosquitoes</i> could pose major challenges for arboviral-borne disease control. In this paper, insecticide susceptibility level and resistance mechanisms were assessed in <i>Aedes aegypti</i> (Linnaeus, 1762) and <i>Aedes albopictus</i> (Skuse, 1894) from urban settings of Cameroon. The F1 progeny of <i>Aedes aegypti</i> and <i>Aedes albopictus</i> collected in Douala, Yaoundé and Dschang from August to December 2020 was tested using WHO tube assays with four insecticides: deltamethrin 0.05%, permethrin 0.75%, DDT 4% and bendiocarb 0.1%. TaqMan, qPCR and RT-qPCR assays were used to detect kdr mutations and the expression profiles of eight detoxification genes. <i>Aedes aegypti</i> mosquitoes from Douala were found to be resistant to DDT, permethrin and deltamethrin. Three kdr mutations, F1534C, V1016G and V1016I were detected in <i>Aedes aegypti</i> populations from Douala and Dschang. The kdr allele F1534C was predominant (90%) in <i>Aedes aegypti</i> and was detected for the first time in <i>Aedes albopictus</i> (2.08%). P450s genes, Cyp9J28 (2.23–7.03 folds), Cyp9M6 (1.49–2.59 folds), Cyp9J32 (1.29–3.75 folds) and GSTD4 (1.34–55.3 folds) were found overexpressed in the Douala and Yaoundé <i>Aedes aegypti</i> populations. The emergence of insecticide resistance in <i>Aedes aegypti</i> and <i>Aedes albopictus</i> calls for alternative strategies towards the control and prevention of arboviral vector-borne diseases in Cameroon.