Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/31254
Title: Insecticide resistance in Aedes aegypti populations from Ceará, Brazil
Authors: Lima, Estelita Pereira
Paiva, Marcelo Henrique Santos
Araújo, Ana Paula de
Silva, Ellyda Vanessa Gomes da
Silva, Ulisses Mariano da
Oliveira, Lúcia Nogueira de
Santana, Antonio Euzébio G.
Barbosa, Clarisse Nogueira
Paiva Neto, Clovis C. de
Goulart, Marilia O. F.
Wilding, Craig Stephen
Ayres, Constância Flávia Junqueira
Santos, Maria Alice V. de Melo
Affilliation: Universidade Federal do Ceará. Fortaleza, CE, Brasil.
Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Recife, PE, Brasil / Faculdade ASCES. Caruaru, PE, Brasil.
Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Recife, PE, Brasil.
Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Recife, PE, Brasil.
Núcleo de Entomologia Médica do Cariri. Juazeiro do Norte, CE, Brasil.
Núcleo de Entomologia Médica do Cariri. Juazeiro do Norte, CE, Brasil.
Universidade Federal de Alagoas. Maceió, AL, Brasil.
Universidade Federal do Ceará. Fortaleza, CE, Brasil.
Universidade Federal do Ceará. Fortaleza, CE, Brasil.
Universidade Federal de Alagoas. Maceió, AL, Brasil.
Liverpool School of Tropical Medicine. Vector Group. Pembroke Place, Liverpool, UK.
Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Recife, PE, Brasil.
Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Recife, PE, Brasil.
Abstract: Background Organophosphates and pyrethroids are used widely in Brazil to control Aedes aegypti, the main vector of dengue viruses, under the auspices of the National Programme for Dengue Control. Resistance to these insecticides is widespread throughout Brazil. In Ceará the vector is present in 98% of districts and resistance to temephos has been reported previously. Here we measure resistance to temephos and the pyrethroid cypermethrin in three populations from Ceará and use biochemical and molecular assays to characterise resistance mechanisms. Results Resistance to temephos varied widely across the three studied populations, with resistance ratios (RR95) of 7.2, 30 and 192.7 in Juazeiro do Norte, Barbalha and Crato respectively. The high levels of resistance detected in Barbalha and Crato (RR95 ≥ 30) imply a reduction of temephos efficacy, and indeed in simulated field tests reduced effectiveness was observed for the Barbalha population. Two populations (Crato and Barbalha) were also resistant to cypermethrin, whilst Juazeiro do Norte showed only an altered susceptibility. The Ile1011Met kdr mutation was detected in all three populations and Val1016Ile in Crato and Juazeiro do Norte. 1011Met was significantly associated with resistance to cypermethrin in the Crato population. Biochemical tests showed that only the activity of esterases and GSTs, among the tested detoxification enzymes, was altered in these populations when compared with the Rockefeller strain. Conclusions Our results demonstrate that two A. aegypti populations from Ceará are under strong selection pressure by temephos, compromising the field effectiveness of this organophosphate. Our results also provide evidence that the process of reducing resistance to this larvicide in the field is difficult and slow and may require more than seven years for reversal. In addition, we show resistance to cypermethrin in two of the three populations studied, and for the first time the presence of the allele 1016Ile in mosquito populations from northeastern Brazil. A significant association between 1011M et and resistance was observed in one of the populations. Target-site mechanisms seem not to be implicated in temephos resistance, reinforcing the idea that for the studied populations, detoxification enzymes most likely play a major role in the resistance to this insecticide.
Keywords: Resistance Level
Cypermethrin
Dengue Hemorrhagic Fever
Resistance Ratio
Mosquito Population
DeCS: Aedes / efeitos de drogas
Aedes / genética
Alelos
Animais
Brasil
Vetores de doenças
Fêmea
Proteínas de Insetos / genética
Resistência a inseticidas
Inseticidas / farmacologia
Masculino
Mutação, Missense
Piretrinas / farmacologia
Seleção Genética
Temefós / farmacologia
Issue Date: 2011
Citation: LIMA, Estelita Pereira et al. Insecticide Resistance in Aedes Aegypti Populations from Ceará, Brazil. Parasites & Vectors, v. 4, p. 5, 12 jan. 2011.
DOI: 10.1186/1756-3305-4-5
ISSN: 1756-3305
Copyright: open access
Appears in Collections:PE - IAM - Artigos de Periódicos

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