PreprintArticleVersion 1Preserved in Portico This version is not peer-reviewed
The G119S Acetylcholinesterase (Ace-1) Target Site Mutation Confers Carbamate Resistance in the Major Malaria Vector Anopheles gambiae from Cameroon: A Challenge for the Coming IRS Implementation
Version 1
: Received: 31 August 2019 / Approved: 1 September 2019 / Online: 1 September 2019 (12:43:29 CEST)
Version 2
: Received: 7 October 2019 / Approved: 8 October 2019 / Online: 8 October 2019 (11:49:05 CEST)
Elanga-Ndille, E.; Nouage, L.; Ndo, C.; Binyang, A.; Assatse, T.; Nguiffo-Nguete, D.; Djonabaye, D.; Irwing, H.; Tene-Fossog, B.; Wondji, C.S. The G119S Acetylcholinesterase (Ace-1) Target Site Mutation Confers Carbamate Resistance in the Major Malaria Vector Anopheles gambiae from Cameroon: A Challenge for the Coming IRS Implementation. Genes2019, 10, 790.
Elanga-Ndille, E.; Nouage, L.; Ndo, C.; Binyang, A.; Assatse, T.; Nguiffo-Nguete, D.; Djonabaye, D.; Irwing, H.; Tene-Fossog, B.; Wondji, C.S. The G119S Acetylcholinesterase (Ace-1) Target Site Mutation Confers Carbamate Resistance in the Major Malaria Vector Anopheles gambiae from Cameroon: A Challenge for the Coming IRS Implementation. Genes 2019, 10, 790.
Abstract
Growing resistance is reported to carbamate insecticides in malaria vectors in Cameroon. However, the contribution of acetylcholinesterase (Ace-1) to this resistance remains uncharacterised. Here, we established that the Ace-1R mutation is driving resistance to carbamates in Anopheles gambiae populations from Cameroon. Insecticide bioassay on field collected mosquitoes from Bankeng, a locality in southern Cameroon, showed high resistance to the carbamates bendiocarb (64.8 ± 3.5 % mortality) and propoxur (55.71 ± 2.9 %) but a full susceptibility to the organophosphate fenithrothion. The TaqMan genotyping of the Ace-1R mutation with field-collected adults revealed the presence of this resistance allele (39%). A significant correlation was observed between the Ace-1R and carbamate resistance at allelic [(bendiocarb; OR = 75.9; P<0.0001) and (propoxur; OR= 1514; P<0.0001)] and genotypic [RR vs SS (bendiocarb; OR = 120.8; P<0.0001) and (propoxur; OR= 3277; P<0.0001) levels. Furthermore, the presence of the mutation was confirmed by sequencing an Ace-1 portion flanking codon 119. The cloning of this fragment revealed a likely duplication of Ace-1 in Cameroon as mosquitoes exhibited at least three distinct haplotypes. Phylogenetic analyses showed that the predominant Ace-1R allele is identical to that from West Africa suggesting a recent introduction of this allele in Central Africa from the West. The spread of this Ace-1R represents a serious challenge to future implementation of IRS-based interventions using carbamates or organophosphates in Cameroon.
Copyright:
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.
Emmanuel Elanga-Ndille
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