title: Fungal infection counters insecticide resistance in African malaria mosquitoes.
abstract: The evolution of insecticide resistance in mosquitoes is threatening the effectiveness and sustainability of malaria control programs in various parts of the world. Through their unique mode of action, entomopathogenic fungi provide promising alternatives to chemical control. However, potential interactions between fungal infection and insecticide resistance, such as cross-resistance, have not been investigated. We show that insecticide-resistant Anopheles mosquitoes remain susceptible to infection with the fungus Beauveria bassiana. Four different mosquito strains with high resistance levels against pyrethroids, organochlorines, or carbamates were equally susceptible to B. bassiana infection as their baseline counterparts, showing significantly reduced mosquito survival. Moreover, fungal infection reduced the expression of resistance to the key public health insecticides permethrin and dichlorodiphenyltrichloroethane. Mosquitoes preinfected with B. bassiana or Metarhizium anisopliae showed a significant increase in mortality after insecticide exposure compared with uninfected control mosquitoes. Our results show a high potential utility of fungal biopesticides for complementing existing vector control measures and provide products for use in resistance management strategies.
authors.affiliation: Laboratory of Entomology, Wageningen University and Research Centre, P.O. Box 8031, 6700 EH Wageningen, The Netherlands.
authors.forename: Marit
authors.initials: M
authors.lastname: Farenhorst
authors.forename: Joel C
authors.initials: JC
authors.lastname: Mouatcho
authors.forename: Christophe K
authors.initials: CK
authors.lastname: Kikankie
authors.forename: Basil D
authors.initials: BD
authors.lastname: Brooke
authors.forename: Richard H
authors.initials: RH
authors.lastname: Hunt
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Thomas
authors.forename: Lizette L
authors.initials: LL
authors.lastname: Koekemoer
authors.forename: Bart G J
authors.initials: BG
authors.lastname: Knols
authors.forename: Maureen
authors.initials: M
authors.lastname: Coetzee
mesh_terms: D000818:Animals; D000852:Anopheles / Q000235:genetics / Q000382:microbiology*; D052982:Beauveria / Q000472:pathogenicity*; D003634:DDT / Q000494:pharmacology; D020022:Genetic Predisposition to Disease; D006801:Humans; D007305:Insecticide Resistance / Q000235:genetics; D007306:Insecticides / Q000494:pharmacology; D008288:Malaria / Q000517:prevention & control*; D009032:Mosquito Control / Q000379:methods; D026023:Permethrin / Q000494:pharmacology*; D013172:Spores, Fungal / Q000472:pathogenicity
chemical_list: D007306:Insecticides; D026023:Permethrin; D003634:DDT