Identification and detection of a novel point mutation in the Chitin Synthase gene of Culex pipiens associated with diflubenzuron resistance.
Journal
PLoS neglected tropical diseases
ISSN: 1935-2735
Titre abrégé: PLoS Negl Trop Dis
Pays: United States
ID NLM: 101291488
Informations de publication
Date de publication:
05 2020
05 2020
Historique:
received:
13
12
2019
accepted:
09
04
2020
revised:
13
05
2020
pubmed:
2
5
2020
medline:
22
7
2020
entrez:
2
5
2020
Statut:
epublish
Résumé
Diflubenzuron (DFB) is one of the most used insecticides in mosquito larval control including that of Culex pipiens, the proven vector of the recent West Nile Virus epidemics in Europe. Two mutations (I1043L and I1043M) in the chitin synthase (CHS) putative binding site of DFB have been previously reported in Cx. pipiens from Italy and associated with high levels of resistance against this larvicide. Here we report the identification of a third mutation at the same I1043 position of the CHS gene resulting in the substitution of Isoleucine to Phenylalanine (I1043F). This mutation has also been found in agricultural pests and has been functionally validated with genome editing in Drosophila, showing to confer striking levels (>15,000 fold) of DFB resistance. The frequency of the I1043F mutation was found to be substantially higher in Cx. pipiens mosquitoes surviving DFB doses largely exceeding the recommended field dose, raising concerns about the future efficient use of this insecticide. We monitored the presence and frequency of DFB mutations in Cx. pipiens mosquitoes from several Mediterranean countries, including Italy, France, Greece, Portugal and Israel. Among the Cx. pipiens populations collected in Northern Italy all but one had at least one of the three DFB mutations at allele frequencies reaching 93.3% for the I1043M, 64.8% for the I1043L and 10% for the I1043F. The newly reported I1043F mutation was also identified in two heterozygote individuals from France (4.2% allelic frequency). In contrast to Italy and France, no DFB resistant mutations were identified in the Cx. pipiens mosquitoes sampled from Greece, Portugal and Israel. The findings of our study are of major concern for mosquito control programs in Europe, that rely on the use of a limited number of available larvicides, and highlight the necessity for the development of appropriate Insecticide Resistance Management (IRM) programs, to ensure the sustainable use of DFB.
Sections du résumé
BACKGROUND
Diflubenzuron (DFB) is one of the most used insecticides in mosquito larval control including that of Culex pipiens, the proven vector of the recent West Nile Virus epidemics in Europe. Two mutations (I1043L and I1043M) in the chitin synthase (CHS) putative binding site of DFB have been previously reported in Cx. pipiens from Italy and associated with high levels of resistance against this larvicide.
METHODOLOGY/PRINCIPAL FINDINGS
Here we report the identification of a third mutation at the same I1043 position of the CHS gene resulting in the substitution of Isoleucine to Phenylalanine (I1043F). This mutation has also been found in agricultural pests and has been functionally validated with genome editing in Drosophila, showing to confer striking levels (>15,000 fold) of DFB resistance. The frequency of the I1043F mutation was found to be substantially higher in Cx. pipiens mosquitoes surviving DFB doses largely exceeding the recommended field dose, raising concerns about the future efficient use of this insecticide. We monitored the presence and frequency of DFB mutations in Cx. pipiens mosquitoes from several Mediterranean countries, including Italy, France, Greece, Portugal and Israel. Among the Cx. pipiens populations collected in Northern Italy all but one had at least one of the three DFB mutations at allele frequencies reaching 93.3% for the I1043M, 64.8% for the I1043L and 10% for the I1043F. The newly reported I1043F mutation was also identified in two heterozygote individuals from France (4.2% allelic frequency). In contrast to Italy and France, no DFB resistant mutations were identified in the Cx. pipiens mosquitoes sampled from Greece, Portugal and Israel.
CONCLUSIONS/SIGNIFICANCE
The findings of our study are of major concern for mosquito control programs in Europe, that rely on the use of a limited number of available larvicides, and highlight the necessity for the development of appropriate Insecticide Resistance Management (IRM) programs, to ensure the sustainable use of DFB.
Identifiants
pubmed: 32357192
doi: 10.1371/journal.pntd.0008284
pii: PNTD-D-19-02006
pmc: PMC7219787
doi:
Substances chimiques
Insect Proteins
0
Insecticides
0
Chitin Synthase
EC 2.4.1.16
Diflubenzuron
J76U6ZSI8D
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
e0008284Déclaration de conflit d'intérêts
he authors have declared that no competing interests exist.
Références
Exp Appl Acarol. 1999 Nov;23(11):851-9
pubmed: 10668860
Insect Sci. 2013 Apr;20(2):121-38
pubmed: 23955853
Proc Natl Acad Sci U S A. 2016 Dec 20;113(51):14692-14697
pubmed: 27930336
Pestic Biochem Physiol. 2019 Nov;161:54-60
pubmed: 31685197
Proc Natl Acad Sci U S A. 2012 Mar 20;109(12):4407-12
pubmed: 22393009
Infect Genet Evol. 2013 Jun;16:218-25
pubmed: 23466890
PLoS Negl Trop Dis. 2019 Jan 3;13(1):e0006822
pubmed: 30605475
Acta Trop. 2020 Mar;203:105294
pubmed: 31836282
PLoS One. 2015 Jun 24;10(6):e0130719
pubmed: 26107715
Acta Trop. 2019 May;193:106-112
pubmed: 30825446
Sci Rep. 2017 Sep 15;7(1):11699
pubmed: 28916816
Acta Trop. 2018 Jun;182:64-68
pubmed: 29474832
Parasit Vectors. 2016 Sep 02;9(1):482
pubmed: 27590848