Multiple insecticide resistance and Plasmodium infection in the principal malaria vectors Anopheles funestus and Anopheles gambiae in a forested locality close to the Yaoundé airport, Cameroon

Wellcome Open Research

article

Francis N. Nkemngo¹  Leon M. J. Mugenzi¹  Ebai Terence¹  Abdoulaye Niang¹  Murielle J. Wondji¹  Micareme Tchoupo¹  Nguiffo D. Nguete¹  Williams Tchapga¹  Helen Irving⁵  Jacques D. M. Ntabi⁶  Romuald Agonhossou⁸  Terence S. Boussougou-Sambe⁹  Romaric B. Akoton⁸  Felix Koukouikila-Koussounda⁶  Yudi T. Pinilla⁹  Francine Ntoumi⁶  Luc S. Djogbenou⁸  Stephen M. Ghogomu³  Cyrille Ndo¹  Ayola A. Adegnika⁹  Steffen Borrmann^1,10  Charles S. Wondji¹ 

[1] Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases ,(CRID), Yaounde, Centre Region;Department of Microbiology and Parasitology, University of Buea;Department of Biochemistry and Molecular Biology, University of Buea;Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow;Department of Vector Biology, Liverpool School of Tropical Medicine;Fondation Congolaise pour la Recherche Medicale;Université Marien Ngouabi;Institut Régional de Santé Publique, Université d'Abomey-Calavi;Centre de Recherches Médicales de Lambaréné;Institute for Tropical Medicine, University of Tübingen;Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala;Eberhard Karls Universität Tübingen;German Center for Infection Research

关键词: Malaria;    Anopheles funestus;    Anopheles gambiae;    Plasmodium infection;    Insecticide resistance;    Vector control;    Cameroon;   

DOI  :  10.12688/wellcomeopenres.15818.2

学科分类：内科医学

来源: Wellcome

【 摘 要 】

Background: Reducing the burden of malaria requires better understanding of vector populations, particularly in forested regions where the incidence remains elevated. Here, we characterized malaria vectors in a locality near the Yaoundé international airport, Cameroon, including species composition, abundance,Plasmodium infection rate, insecticide resistance profiles and underlying resistance mechanisms.Methods: Blood-fed adult mosquitoes resting indoors were aspirated from houses in April 2019 at Elende, a locality situated 2 km from the Yaoundé-Nsimalen airport. Female mosquitoes were forced to lay eggs to generate F1 adults. Bioassays were performed to assess resistance profile to the four insecticides classes. The threshold of insecticide susceptibility was defined above 98% mortality rate and mortality rates below 90% were indicative of confirmed insecticide resistance. Furthermore, the molecular basis of resistance andPlasmodium infection rates were investigated.Results:Anopheles funestus s.s. was the most abundant species in Elende (85%) followed byAnopheles gambiae s.s. (15%) with both having similar sporozoite rate. Both species exhibited high levels of resistance to the pyrethroids, permethrin and deltamethrin (<40% mortality).An. gambiae s.s. was resistant to DDT (9.9% mortality) and bendiocarb (54% mortality) while susceptible to organophosphate.An. funestus s.s. was resistant to dieldrin (1% mortality), DDT (86% mortality) but susceptible to carbamates and organophosphates. The L119F-GSTe2 resistance allele (8%) and G119Sace-1 resistance allele (15%) were detected inAn. funestus s.s. andAn. gambiae s.s., respectively. Furthermore, the high pyrethroid/DDT resistances inAn. gambiae corresponded with an increase frequency of 1014Fkdr allele (95%). Transcriptional profiling of candidate cytochrome P450 genes reveals the over-expression ofCYP6P5,CYP6P9a andCYP6P9b.Conclusion: The resistance to multiple insecticide classes observed in these vector populations alongside the significantPlasmodium sporozoite rate highlights the challenges that vector control programs encounter in sustaining the regular benefits of contemporary insecticide-based control interventions in forested areas.

【 授权许可】

CC BY