title: Susceptibility to insecticides and resistance mechanisms in Aedes aegypti from the Colombian Caribbean Region.
abstract: We determined the susceptibility to insecticides and the biochemical and molecular mechanisms involved in resistance in nine populations of Aedes aegypti (L.) of the Colombian Caribbean region. Bioassays were performed on larvae for susceptibility to temephos and on adults to the insecticides malathion, fenitrothion, pirimiphos-methyl, permethrin, deltamethrin, λ-cyhalothrin and cyfluthrin. The resistance ratio (RR) for each insecticide in the populations was determined, using the susceptible Rockefeller strain as a susceptible control. Additionally, we evaluated the response of the populations to the diagnostic dose (DD) of the organochlorine pesticide DDT. The following biochemical mechanisms associated with resistance were studied: α-esterases, β-esterases, mixed-function oxidases (MFO), glutathione s-transferases (GST) and insensitive acetylcholinesterase (iAChE) as well as the presence of kdr I1,016 mutation and its frequency. All populations studied showed susceptibility to the organophosphates evaluated (RR < 5-fold), except for the Puerto Colombia and Soledad populations which showed high resistance (RR 15-fold) and moderate resistance (RR 5-fold) to temephos, respectively, and Sincelejo (Sucre) with moderate resistance to pirimiphos-methyl (RR 5-fold). All populations evaluated with DD of DDT were found to be resistant with 2-28% of mortality. Variability was observed in the resistance to pyrethroids: permethrin (RR 1.2- to 30.8-fold), deltamethrin RR 0.9- to 37.8-fold), λ-cyalothrin (RR 3.4- to 83-fold) and cyfluthrin (RR 0.3- to 33.8-fold). Incipiently α-esterases and MFO levels were found in the Valledupar population; MFO showed the same profile in Cienaga and GST in the Sincelejo population, all other populations showed unaltered profiles of the enzymes evaluated. The kdr I1,016 mutation was found in all populations evaluated with variability in its allelic and genotypic frequencies.
authors.affiliation: Universidad de Cartagena, Facultad de Medicina - Sede Zaragocilla, Calle 30 N° 48 - 152, Cartagena de Indias (Bolivar) 1300, Colombia.
authors.forename: Ronald
authors.initials: R
authors.lastname: Maestre-Serrano
authors.affiliation: Universidad de Cartagena, Facultad de Medicina - Sede Zaragocilla, Calle 30 N° 48 - 152, Cartagena de Indias (Bolivar) 1300, Colombia.
authors.forename: Doris
authors.initials: D
authors.lastname: Gomez-Camargo
authors.affiliation: Universidad Autonoma de Nuevo Leon, Facultad de Ciencias Biologicas, Av. Universidad s/n Cd. Universitaria, San Nicolas de los Garza, NL 66451, Mexico.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Ponce-Garcia
authors.affiliation: Universidad Autonoma de Nuevo Leon, Facultad de Ciencias Biologicas, Av. Universidad s/n Cd. Universitaria, San Nicolas de los Garza, NL 66451, Mexico. Electronic address: adriana.floressr@uanl.edu.mx.
authors.forename: Adriana E
authors.initials: AE
authors.lastname: Flores
mesh_terms: D000330:Aedes / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D017691:Caribbean Region; D003105:Colombia; D003634:DDT / Q000633:toxicity; D004950:Esterases / Q000378:metabolism; D005260:Female; D017344:Genes, Insect / Q000235:genetics; D005978:Glutathione / Q000378:metabolism; D007305:Insecticide Resistance / Q000235:genetics; D007306:Insecticides / Q000633:toxicity*; D007814:Larva / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D007928:Lethal Dose 50; D006899:Mixed Function Oxygenases / Q000378:metabolism; D009154:Mutation; D009943:Organophosphorus Compounds / Q000633:toxicity*; D011722:Pyrethrins / Q000633:toxicity*
chemical_list: D007306:Insecticides; D009943:Organophosphorus Compounds; D011722:Pyrethrins; D003634:DDT; D006899:Mixed Function Oxygenases; D004950:Esterases; D005978:Glutathione
keywords: Aedes aegypti; DDT; Organophosphates; Pyrethroids; kdr I1,016