Journal Article

Phenotypic effects of concomitant insensitive acetylcholinesterase (ace-1R) and knockdown resistance (kdrR) in Anopheles gambiae: a hindrance for insecticide resistance management for malaria vector control

Djogbénou, Luc S, Djegbe, Innocent, Milesi, Pascal, Djossou, Laurette, Assogba, Benoît S, Weill, Mylene, Baba-Moussa, Lamine, Saizonou, Jacques, Chandre, Fabrice, Oumbouke, Welbeck A, Makoutodé, Michel

2014

Overview

Background Malaria is endemic in sub-Saharan Africa with considerable burden for human health. Major insecticide resistance mechanisms such as kdr R and ace-1 R alleles constitute a hindrance to malaria vector control programs. Anopheles gambiae bearing both kdr and ace-1 resistant alleles are increasingly recorded in wild populations. In order to maintain the efficacy of vector control strategies, the characterization of concomitant kdr and ace-1 resistance, and their pleiotropic effects on malaria vector phenotype on insecticide efficacy are important. Methods Larval and adult bioassays were performed with different insecticide classes used in public health following WHO standard guidelines on four laboratory Anopheles gambiae strains, sharing the same genetic background but harboring distinct resistance status: KISUMU with no resistance allele; ACERKIS with ace-1 R allele; KISKDR with kdr R allele and ACERKDRKIS with both resistance alleles’ ace-1 R and kdr R . Results Larval bioassays indicate that the homozygote resistant strain harboring both alleles (ACERKDRKIS) displayed slightly but significantly higher resistance level to various insecticides like carbamates (bendiocarb, p  < 0.001; propoxur, p  = 0.02) and organophosphates (chlorpyriphos-methyl, p  = 0.002; fenitrothion, p  < 0.001) when compared to ACERKIS strain. However, no differences were recorded between ACERKDRKIS and KISKDR resistance level against permethrin (Pyrethroid, p  = 0.7) and DDT (Organochlorine, p  = 0.24). For adult bioassays, the percentages of mosquitoes knocked down were significantly lower for ACERKDRKIS than for KISKDR with permethrin ( p  = 0.003) but not with deltamethrin. The percentage of mortality from adult bioassays was similar between ACERKDRKIS and ACERKIS with carbamates and organophosphates, or between ACERKDRKIS and KISKDR with pyrethroid and DDT. Concerning acetylcholinesterase enzyme, ACERKDRKIS strain showed similarAChE1 activity than that of ACERKIS. Conclusion The presence of both kdr R and ace-1 R alleles seems to increase the resistance levels to both carbamate and organophosphate insecticides and at operational level, may represent an important threat to malaria vector control programs in West Africa.

• Publisher: BioMed Central,Springer Nature B.V,BMC
• Subject: acetylcholinesterase / Acetylcholinesterase - genetics / Acetylcholinesterase - metabolism / adults / alleles / Animals / Anopheles - drug effects / Anopheles - genetics / Anopheles gambiae / bendiocarb / bioassays / Biodiversity and Ecology / Biological Assay / Biomedical and Life Sciences / Biomedicine / Concomitant effects / DDT (pesticide) / deltamethrin / Entomology / Environmental Sciences / fenitrothion / Gene Expression Regulation, Enzymologic / genetic background / guidelines / human health / Infectious Diseases / insecticide resistance / Insecticide Resistance - genetics / Insecticide resistance genes / Insecticides / Insecticides - pharmacology / Larva - drug effects / larvae / Malaria / mortality / Mosquitoes / Mutation / Parasitology / permethrin / phenotype / propoxur / public health / pyrethrins / resistance management / resistance mechanisms / Studies / Tropical Medicine / Vector control / Veterinary Medicine/Veterinary Science / Virology / Western Africa / World Health Organization