title: Insecticide resistance in the dengue vector Aedes aegypti from Martinique: distribution, mechanisms and relations with environmental factors.
abstract: Dengue is an important mosquito borne viral disease in Martinique Island (French West Indies). The viruses responsible for dengue are transmitted by Aedes aegypti, an indoor day-biting mosquito. The most effective proven method for disease prevention has been by vector control by various chemical or biological means. Unfortunately insecticide resistance has already been observed on the Island and recently showed to significantly reduce the efficacy of vector control interventions. In this study, we investigated the distribution of resistance and the underlying mechanisms in nine Ae. aegypti populations. Statistical multifactorial approach was used to investigate the correlations between insecticide resistance levels, associated mechanisms and environmental factors characterizing the mosquito populations. Bioassays revealed high levels of resistance to temephos and deltamethrin and susceptibility to Bti in the 9 populations tested. Biochemical assays showed elevated detoxification enzyme activities of monooxygenases, carboxylesterases and glutathione S-tranferases in most of the populations. Molecular screening for common insecticide target-site mutations, revealed the presence of the "knock-down resistance" V1016I Kdr mutation at high frequency (>87%). Real time quantitative RT-PCR showed the potential involvement of several candidate detoxification genes in insecticide resistance. Principal Component Analysis (PCA) performed with variables characterizing Ae. aegypti from Martinique permitted to underline potential links existing between resistance distribution and other variables such as agriculture practices, vector control interventions and urbanization. Insecticide resistance is widespread but not homogeneously distributed across Martinique. The influence of environmental and operational factors on the evolution of the resistance and mechanisms are discussed.
authors.affiliation: Unité Mixte de Recherche MIVEGEC (UM1-CNRS 5290-IRD 224), Institut de Recherche pour le Développement (IRD), Montpellier, France. sebastien.marcombe@ird.fr
authors.forename: Sébastien
authors.initials: S
authors.lastname: Marcombe
authors.forename: Romain Blanc
authors.initials: RB
authors.lastname: Mathieu
authors.forename: Nicolas
authors.initials: N
authors.lastname: Pocquet
authors.forename: Muhammad-Asam
authors.initials: MA
authors.lastname: Riaz
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Poupardin
authors.forename: Serge
authors.initials: S
authors.lastname: Sélior
authors.forename: Frédéric
authors.initials: F
authors.lastname: Darriet
authors.forename: Stéphane
authors.initials: S
authors.lastname: Reynaud
authors.forename: André
authors.initials: A
authors.lastname: Yébakima
authors.forename: Vincent
authors.initials: V
authors.lastname: Corbel
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: David
authors.forename: Fabrice
authors.initials: F
authors.lastname: Chandre
mesh_terms: D000110:Acetylcholinesterase / Q000235:genetics / Q000378:metabolism; D000330:Aedes / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D000375:Aging / Q000187:drug effects; D000818:Animals; D001681:Biological Assay; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D003715:Dengue / Q000469:parasitology*; D004777:Environment; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D017344:Genes, Insect / Q000235:genetics; D056726:Genetic Association Studies; D005838:Genotype; D005843:Geography; D007303:Insect Vectors / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D007305:Insecticide Resistance / Q000187:drug effects* / Q000235:genetics; D007814:Larva / Q000187:drug effects / Q000235:genetics; D008395:Martinique; D009154:Mutation / Q000235:genetics; D009570:Nitriles / Q000633:toxicity*; D010641:Phenotype; D011157:Population Dynamics; D025341:Principal Component Analysis; D011722:Pyrethrins / Q000633:toxicity*; D012015:Reference Standards; D000002:Temefos / Q000633:toxicity*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin; D003577:Cytochrome P-450 Enzyme System; D000110:Acetylcholinesterase; D000002:Temefos