Insecticide resistance status of Anopheles gambiae s.s population from M’Bé: a WHOPES-labelled experimental hut station, 10 years after the political crisis in Côte d’Ivoire

Malaria Journal

Research

Alphonsine A Koffi¹  Maurice A Adja²  Ludovic P Ahoua Alou²  Fabrice Chandre³  Cédric Pennetier⁴ 

[1] Institut Pierre Richet (IPR), BP 47, Abidjan, Côte d’Ivoire;Institut Pierre Richet (IPR), BP 47, Abidjan, Côte d’Ivoire;Laboratoire de Zoologie et Biologie Animale, Université Felix Houphouët-Boigny de Cocody, 22 BP 582, Abidjan, Côte d’Ivoire;Institut de Recherche pour le Développement (IRD)/UMR224 MiVEGEC, 34394, Montpellier, France;Institut de Recherche pour le Développement (IRD)/UMR224 MiVEGEC, 34394, Montpellier, France;Centre de Recherche Entomologique de Cotonou, 06 BP 2604, Cotonou, Bénin;

关键词: Insecticide-resistance;    Anopheles gambiae;    M’Bé;    Côte d’Ivoire;   

DOI  :  10.1186/1475-2875-12-151

 received in 2012-11-30, accepted in 2013-04-26,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundAn experimental hut station built at M’Bé in 1998 was used for many years for the evaluation of insecticidal product for public health until the civil war broke out in 2002. Breeding sites of mosquitoes and selection pressure in the area were maintained by local farming practices and the West African Rice Development Association (WARDA, actually AfricaRice) in a large rice growing area. Ten years after the crisis, bioassays, molecular and biochemical analyses were conducted to update the resistance status and study the evolution of resistance mechanisms of Anopheles gambiae s.s population.MethodsAnopheles gambiae s.s larvae from M’Bé were collected in breeding sites and reared until emergence. Resistance status of this population to conventional insecticides was assessed using WHO bioassay test kits for adult mosquitoes, with 10 insecticides belonging to pyrethroids, pseudo-pyrethroid, organochlorides, carbamates and organophosphates with and without the inhibitor piperonyl butoxyde (PBO). Molecular and biochemical assays were carried out to identify the L1014F kdr, L1014S kdr and ace-1R alleles in individual mosquitoes and to detect potential increase in mixed function oxidases (MFO) level, non-specific esterases (NSE) and glutathione S-transferases (GST) activities.Results and discussionAnopheles gambiae s.s from M’Bé exerted high resistance levels to organochlorides, pyrethroids, and carbamates. Mortalities ranged from 3% to 21% for organochlorides, from 50% to 75% for pyrethroids, 34% for etofenprox, the pseudo-pyrethroid, and from 7% to 80% for carbamates. Tolerance to organophosphates was observed with mortalities ranging from 95% to 98%. Bioassays run with a pre-exposition of mosquitoes to PBO induced very high levels of mortalities compared to the bioassays without PBO, suggesting that the resistance to pyrethroid and carbamate relied largely on detoxifying enzymes’ activities. The L1014F kdr allelic frequency was 0.33 in 2012 compared to 0.05 before the crisis in 2002. Neither the L1014S kdr nor ace-1R mutations were detected. An increased activity of NSE and level of MFO was found relative to the reference strain Kisumu. This was the first evidence of metabolic resistance based resistance in An. gambiae s.s from M’Bé.ConclusionThe An. gambiae s.s population showed very high resistance to organochlorides, pyrethroids and carbamates. This resistance level relied largely on two major types of resistance: metabolic and target-site mutation. This multifactorial resistance offers a unique opportunity to evaluate the impact of both mechanisms and their interaction with the vector control tools currently used or in development.

【 授权许可】

CC BY   
© Koffi et al.; licensee BioMed Central Ltd. 2013