Volume 20, Issue 3, June 2017, Pages 983–993
Innocent Djegbe1, Gado Dramane2, Francis Zeukeng3, Martin AKOGBETO4, and Rousseau Djouaka5
1 University of Sciences, Arts and Techniques of Natitingou, Ecole Normale Supérieure de Natitingou, P.O. Box 72, Natitingou, Benin
2 University of Sciences, Arts and Techniques of Natitingou, Ecole Normale Supérieure de Natitingou, P.O. Box 72, Natitingou, Benin
3 Department of Biochemistry, Faculty of Sciences, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon
4 Centre de Recherche Entomologique de Cotonou, Benin
5 The AgroEcoHealth Platform, International Institute of Tropical Agriculture, 08 P.O. Box 0932 Tri-postal Cotonou, Benin
Original language: English
Copyright © 2017 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
We investigated the impact of the kdr genotypes on the survival rate of mosquitoes exposed to insecticides in the main malaria vectors Anopheles coluzzii and An. gambiae s.s.. The genotype-phenotype interaction was investigated following two experimental designs; the first one consisted to determine the survival rate of well-characterized adult mosquito strains sharing different kdr genotypes but same genetic background to various insecticides, whereas the second one consisted to expose wild mosquitoes to the same insecticides. Two to five days old adult females were exposed to DDT (4%), deltamethrin (0.05%), and permethrin (0.75%) following WHO protocols. Alive and dead specimens were kept separately to screen the kdr mutations 1014F. The correlation between the kdr genotype and the survival rate to insecticides was investigated in An. coluzzii and An. gambiae s.s. using a logistic regression model. In the laboratory strains, after exposure to DDT and permethrin, the survival rate was significantly higher in F/F individuals comparing to L/F and L/L individuals (p<0.05). A perfect correlation was observed between the survival rate and the genotype in An. gambiae s.s.. The survival chance in this population was multiplied by 1.9 [1.2; 2.8] for L/F and 3.2 [2.1; 4.7] for F/F individuals after exposure to DDT; and 3.7 [1.8; 7.3] for L/F and 9 [4.8; 17.0] for F/F individuals after exposure to permethrin. In the wild population of An. coluzzii, the survival rate correlated with the genotype after exposure to permethrin and was significantly higher in F/F individuals comparing to L/F and L/L individuals (p<0.05). In L/F and F/F individuals, the survival chance was respectively multiplied by 2.7 [1.4; 5.8] and 3.2 [1.4; 6.9] after exposure to DDT; 2.1 [1.0; 4.1] and 4.1 [2.3; 8.7] after exposure to permethrin; and 2.5 [1.1; 5.3] and 3.9 [1.9; 8.0] after exposure to deltamethrin. Overall, the mosquito survival rates were significantly higher in wild population comparing to laboratory strains after exposure to pyrethroid insecticides. These results suggest that additional mechanisms such as metabolic resistance might contribute to a large extend to phenotypic resistance in malaria vectors.
Author Keywords: kdr mutation, kdr genotype, phenotypic-resistance, An. gambiae s.l..
Innocent Djegbe1, Gado Dramane2, Francis Zeukeng3, Martin AKOGBETO4, and Rousseau Djouaka5
1 University of Sciences, Arts and Techniques of Natitingou, Ecole Normale Supérieure de Natitingou, P.O. Box 72, Natitingou, Benin
2 University of Sciences, Arts and Techniques of Natitingou, Ecole Normale Supérieure de Natitingou, P.O. Box 72, Natitingou, Benin
3 Department of Biochemistry, Faculty of Sciences, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon
4 Centre de Recherche Entomologique de Cotonou, Benin
5 The AgroEcoHealth Platform, International Institute of Tropical Agriculture, 08 P.O. Box 0932 Tri-postal Cotonou, Benin
Original language: English
Copyright © 2017 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
We investigated the impact of the kdr genotypes on the survival rate of mosquitoes exposed to insecticides in the main malaria vectors Anopheles coluzzii and An. gambiae s.s.. The genotype-phenotype interaction was investigated following two experimental designs; the first one consisted to determine the survival rate of well-characterized adult mosquito strains sharing different kdr genotypes but same genetic background to various insecticides, whereas the second one consisted to expose wild mosquitoes to the same insecticides. Two to five days old adult females were exposed to DDT (4%), deltamethrin (0.05%), and permethrin (0.75%) following WHO protocols. Alive and dead specimens were kept separately to screen the kdr mutations 1014F. The correlation between the kdr genotype and the survival rate to insecticides was investigated in An. coluzzii and An. gambiae s.s. using a logistic regression model. In the laboratory strains, after exposure to DDT and permethrin, the survival rate was significantly higher in F/F individuals comparing to L/F and L/L individuals (p<0.05). A perfect correlation was observed between the survival rate and the genotype in An. gambiae s.s.. The survival chance in this population was multiplied by 1.9 [1.2; 2.8] for L/F and 3.2 [2.1; 4.7] for F/F individuals after exposure to DDT; and 3.7 [1.8; 7.3] for L/F and 9 [4.8; 17.0] for F/F individuals after exposure to permethrin. In the wild population of An. coluzzii, the survival rate correlated with the genotype after exposure to permethrin and was significantly higher in F/F individuals comparing to L/F and L/L individuals (p<0.05). In L/F and F/F individuals, the survival chance was respectively multiplied by 2.7 [1.4; 5.8] and 3.2 [1.4; 6.9] after exposure to DDT; 2.1 [1.0; 4.1] and 4.1 [2.3; 8.7] after exposure to permethrin; and 2.5 [1.1; 5.3] and 3.9 [1.9; 8.0] after exposure to deltamethrin. Overall, the mosquito survival rates were significantly higher in wild population comparing to laboratory strains after exposure to pyrethroid insecticides. These results suggest that additional mechanisms such as metabolic resistance might contribute to a large extend to phenotypic resistance in malaria vectors.
Author Keywords: kdr mutation, kdr genotype, phenotypic-resistance, An. gambiae s.l..
How to Cite this Article
Innocent Djegbe, Gado Dramane, Francis Zeukeng, Martin AKOGBETO, and Rousseau Djouaka, “Relationship between kdr L1014F genotypes and phenotypic-resistance to pyrethroids and DDT insecticides in Anopheles gambiae s.l.,” International Journal of Innovation and Applied Studies, vol. 20, no. 3, pp. 983–993, June 2017.
