title: Evidence that agricultural use of pesticides selects pyrethroid resistance within Anopheles gambiae s.l. populations from cotton growing areas in Burkina Faso, West Africa.
abstract: Many studies have shown the role of agriculture in the selection and spread of resistance of Anopheles gambiae s.l. to insecticides. However, no study has directly demonstrated the presence of insecticides in breeding sources as a source of selection for this resistance. It is in this context that we investigated the presence of pesticide residues in breeding habitats and their formal involvement in vector resistance to insecticides in areas of West Africa with intensive farming. This study was carried out from June to November 2013 in Dano, southwest Burkina Faso in areas of conventional (CC) and biological cotton (BC) growing. Water and sediment samples collected from breeding sites located near BC and CC fields were submitted for chromatographic analysis to research and titrate the residual insecticide content found there. Larvae were also collected in these breeding sites and used in toxicity tests to compare their mortality to those of the susceptible strain, Anopheles gambiae Kisumu. All tested mosquitoes (living and dead) were analyzed by PCR for species identification and characterization of resistance genes. The toxicity analysis of water from breeding sites showed significantly lower mortality rates in breeding site water from biological cotton (WBC) growing sites compared to that from conventional cotton (WCC) sites respective to both An. gambiae Kisumu (WBC: 80.75% vs WCC: 92.75%) and a wild-type strain (49.75% vs 66.5%). The allele frequencies L1014F, L1014S kdr, and G116S ace -1R mutations conferring resistance, respectively, to pyrethroids and carbamates / organophosphates were 0.95, 0.4 and 0.12. Deltamethrin and lambda-cyhalothrin were identified in the water samples taken in October/November from mosquitoes breeding in the CC growing area. The concentrations obtained were respectively 0.0147ug/L and 1.49 ug/L to deltamethrin and lambdacyhalothrin. Our results provided evidence by direct analysis (biological and chromatographic tests) of the role of agriculture as a source of selection pressure on vectors to insecticides used in growing areas.
authors.affiliation: IRSS/DRO, Malaria and Tropical Neglected Research Unit, Bobo-Dioulasso, Burkina Faso.
authors.forename: Aristide Sawdetuo
authors.initials: AS
authors.lastname: Hien
authors.affiliation: IRSS/DRO, Malaria and Tropical Neglected Research Unit, Bobo-Dioulasso, Burkina Faso.
authors.forename: Dieudonné Diloma
authors.initials: DD
authors.lastname: Soma
authors.affiliation: Programme Coton/INERA/ Farako-Ba, Bobo-Dioulasso, Burkina Faso.
authors.forename: Omer
authors.initials: O
authors.lastname: Hema
authors.affiliation: IRSS/DRO, Malaria and Tropical Neglected Research Unit, Bobo-Dioulasso, Burkina Faso.
authors.forename: Bazoma
authors.initials: B
authors.lastname: Bayili
authors.affiliation: Institute of Rural Development, Université Polytechnique de Bobo-Dioulasso, Burkina Faso.
authors.forename: Moussa
authors.initials: M
authors.lastname: Namountougou
authors.affiliation: UFR/Life Science, Université Joseph Ki-Zerbo, Ouagadougou, Burkina Faso.
authors.forename: Olivier
authors.initials: O
authors.lastname: Gnankiné
authors.affiliation: CIRAD, Campus de Baillarguet, Montpellier, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Baldet
authors.affiliation: IRSS/DRO, Malaria and Tropical Neglected Research Unit, Bobo-Dioulasso, Burkina Faso.
authors.forename: Abdoulaye
authors.initials: A
authors.lastname: Diabaté
authors.affiliation: IRSS/DRO, Malaria and Tropical Neglected Research Unit, Bobo-Dioulasso, Burkina Faso.
authors.forename: Kounbobr Roch
authors.initials: KR
authors.lastname: Dabiré
mesh_terms: D000354:Africa, Western; D000383:Agriculture; D000818:Animals; D000852:Anopheles / Q000187:drug effects* / Q000235:genetics; D002050:Burkina Faso; D004351:Drug Resistance; D003368:Gossypium / Q000737:chemistry*; D007305:Insecticide Resistance; D009154:Mutation; D010575:Pesticides; D016133:Polymerase Chain Reaction; D011722:Pyrethrins / Q000494:pharmacology*
chemical_list: D010575:Pesticides; D011722:Pyrethrins