Insecticide exposure impacts vector-parasite interactions in insecticide-resistant malaria vectors.
Currently, there is a strong trend towards increasing insecticide-based vector control coverage in malaria endemic countries. The ecological consequence of insecticide applications has been mainly studied regarding the selection of resistance mechanisms; however, little is known about their impact on vector competence in mosquitoes responsible for malaria transmission. As they have limited toxicity to mosquitoes owing to the selection of resistance mechanisms, insecticides may also interact with pathogens developing in mosquitoes. In this study, we explored the impact of insecticide exposure on Plasmodium falciparum development in insecticide-resistant colonies of Anopheles gambiae s.s., homozygous for the ace-1 G119S mutation (Acerkis) or the kdr L1014F mutation (Kdrkis). Exposure to bendiocarb insecticide reduced the prevalence and intensity of P. falciparum oocysts developing in the infected midgut of the Acerkis strain, whereas exposure to dichlorodiphenyltrichloroethane reduced only the prevalence of P. falciparum infection in the Kdrkis strain. Thus, insecticide resistance leads to a selective pressure of insecticides on Plasmodium parasites, providing, to our knowledge, the first evidence of genotype by environment interactions on vector competence in a natural Anopheles-Plasmodium combination. Insecticide applications would affect the transmission of malaria in spite of resistance and would reduce to some degree the impact of insecticide resistance on malaria control interventions.
Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UM1-UM2-CNRS 5290 IRD 224, Montpellier, France Institut de Recherche en Sciences de la Santé (IRSS), 01 BP 545 Bobo-Dioulasso 01, Burkina Faso haoues.alout@colostate.edu.
Haoues
H
Alout
Centre de Recherche Entomologique de Cotonou, Université d'Abomey-Calavi, 06 BP 2604 Cotonou, Bénin.
Innocent
I
Djègbè
Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UM1-UM2-CNRS 5290 IRD 224, Montpellier, France.
Fabrice
F
Chandre
Institut Régional de Santé Publique, Université d'Abomey-Calavi, 01 BP 918 Cotonou, Bénin.
Luc Salako
LS
Djogbénou
Institut de Recherche en Sciences de la Santé (IRSS), 01 BP 545 Bobo-Dioulasso 01, Burkina Faso.
Roch Kounbobr
RK
Dabiré
Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UM1-UM2-CNRS 5290 IRD 224, Montpellier, France Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand.
Vincent
V
Corbel
Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UM1-UM2-CNRS 5290 IRD 224, Montpellier, France Institut de Recherche en Sciences de la Santé (IRSS), 01 BP 545 Bobo-Dioulasso 01, Burkina Faso.
Anna
A
Cohuet
D000818:Animals; D000852:Anopheles / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D003634:DDT / Q000494:pharmacology; D005247:Feeding Behavior / Q000187:drug effects; D005260:Female; D059647:Gene-Environment Interaction; D005838:Genotype; D006790:Host-Parasite Interactions / Q000187:drug effects*; D006801:Humans; D007303:Insect Vectors / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D033661:Oocysts / Q000187:drug effects / Q000254:growth & development; D048448:Phenylcarbamates / Q000494:pharmacology; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000254:growth & development
D007306:Insecticides; D048448:Phenylcarbamates; D003634:DDT; C007725:bendiocarb
Anopheles gambiae; Plasmodium falciparum; insecticide exposure; insecticide resistance; malaria transmission; vector competence