Insecticide Resistance in the Dengue Vector Aedes aegypti from Martinique: Distribution, Mechanisms and Relations with Environmental Factors

Abstract

Dengue is an important mosquito borne viral disease in Martinique Island (French West Indies). The viruses responsible for dengue are transmitted by Aedes aegypti, an indoor day-biting mosquito. The most effective proven method for disease prevention has been by vector control by various chemical or biological means. Unfortunately insecticide resistance has already been observed on the Island and recently showed to significantly reduce the efficacy of vector control interventions. In this study, we investigated the distribution of resistance and the underlying mechanisms in nine Ae. aegypti populations. Statistical multifactorial approach was used to investigate the correlations between insecticide resistance levels, associated mechanisms and environmental factors characterizing the mosquito populations. Bioassays revealed high levels of resistance to temephos and deltamethrin and susceptibility to Bti in the 9 populations tested. Biochemical assays showed elevated detoxification enzyme activities of monooxygenases, carboxylesterases and glutathione S-tranferases in most of the populations. Molecular screening for common insecticide target-site mutations, revealed the presence of the “knock-down resistance” V1016I Kdr mutation at high frequency (>87%). Real time quantitative RT-PCR showed the potential involvement of several candidate detoxification genes in insecticide resistance. Principal Component Analysis (PCA) performed with variables characterizing Ae. aegypti from Martinique permitted to underline potential links existing between resistance distribution and other variables such as agriculture practices, vector control interventions and urbanization. Insecticide resistance is widespread but not homogeneously distributed across Martinique. The influence of environmental and operational factors on the evolution of the resistance and mechanisms are discussed.

Identifying genomic changes associated with insecticide resistance in the dengue mosquito Aedes aegypti by deep targeted sequencing

“…In this previous study, the overtranscription of CCEAE3A and CCEAE6A through gene amplification was associated with temephos resistance at the larval stage, although resistance to pyrethroids was also observed. Other studies performed on South American and Caribbean populations confirmed the association of some of these CCEs with temephos resistance (Marcombe et al 2009(Marcombe et al , 2012Saavedra-Rodriguez et al 2014). Our data revealed higher CCE copy number in mosquitoes surviving deltamethrin exposure (R+ phenotype), supporting their role in pyrethroid resistance.…”

Insecticide resistance and genetic variability in natural populations of Aedes (Stegomyia) aegypti (Diptera: Culicidae) from Colombia

“…In populations of A. aegypti from Latin America and Southeast Asia, the mutations Val1016Ile, Val1016Gly, Phe1534Cys and Asp1794Tyr, all in the IIS6 and IIIS6 segment, are correlated with insecticide resistance (BRENGUES et al 2003, CHANG et al 2009, HARRIS et al 2010, LINSS et al 2014. However, only one of these, a valine to isoleucine substitution at codon 1016, has been clearly linked to insecticide resistance; selection pressure under laboratory conditions, bioassays with adults, biochemical assays and molecular screening have confirmed this finding (RODPRADIT et al 2005, STRODE et al 2008, GARCÍA et al 2009, MARTINS et al 2009, LUMJUAN et al 2011, MARCOMBE et al 2012.…”

Larvicidal, pupicidal and insecticidal activities of <i>Cosmos bipinnatus</i>, <i>Foeniculum vulgare</i> and <i>Tagetes minuta</i> against <i>Culex quinquefasciatus</i> mosquitoes

“…Ethanol extracts of Citrus sinensis have displayed both larvicidal and pupicidal activities against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus mosquitoes [20], and similar bioactivities were observed for F. vulgare, C. bipinnatus and Tagetes minuta ethanol extracts in this study against larva and pupa of C. quinquefasciatus mosquitoes. F. vulgare seed essential oil extract was reported for larvicidal activity on both 2nd and 4th larval instar of Culex pipiens [21], and the non-polar compounds present in the hexane extract can similarly act on larvae of C. quinquefasciatus mosquitoes.…”