First detection of F1534C knockdown resistance mutation in Aedes aegypti (Diptera: Culicidae) from Cameroon

Infectious Diseases of Poverty

Basile Kamgang¹  Daniel Nguiffo-Nguete²  Theodel A. Wilson Bahun³  Charles S. Wondji⁴  Armel N. Tedjou⁵  Aurelie P. Yougang⁵  Flobert Njiokou⁶ 

[1] Centre for Research in Infectious Diseases, P.O. Box 13591, Yaoundé, Cameroon;Centre for Research in Infectious Diseases, P.O. Box 13591, Yaoundé, Cameroon;Laboratory of Biology and Applied Ecology, Department of Animal Biology, Faculty of Science, University of Dschang, P.O. Box 96, Dschang, Cameroon;Centre for Research in Infectious Diseases, P.O. Box 13591, Yaoundé, Cameroon;Laboratory of Vertebrate and Invertebrate Bioecology, Faculty of Science and Technology, Marien-Ngouabi University, Brazzaville, Congo;Centre for Research in Infectious Diseases, P.O. Box 13591, Yaoundé, Cameroon;Liverpool School of Tropical Medicine, Pembroke place, L3 5QA, Liverpool, UK;Centre for Research in Infectious Diseases, P.O. Box 13591, Yaoundé, Cameroon;Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon;Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon;

关键词: Aedes aegypti;    Insecticide resistance;    Kdr;    Cameroon;    Arbovirus;   

DOI  :  10.1186/s40249-020-00769-1

来源: Springer

【 摘 要 】

BackgroundAedes borne viral diseases, notably dengue, are increasingly reported in Cameroon with Aedes aegypti being a major vector. Data on insecticide resistance of this vector and underlying mechanisms needed for outbreak preparedness remain scarce in Cameroon. Here, we present the nationwide distribution of insecticide resistance in Ae. aegypti and investigate the potential resistance mechanisms involved.MethodsImmature stages of Ae. aegypti were collected between March and July 2017 in 13 locations across Cameroon and reared until G1/G2/G3 generation. Larval, adult bioassays, and piperonyl butoxide (PBO) synergist assays were carried out according to World Health Organization guidelines. F1534C mutation was genotyped using allele specific polymerase chain reaction in field collected adults (Go) and the polymorphism of the sodium channel gene was assessed. The χ2 test was used to compare the mortality rate between bioassays with insecticides only and bioassays after preexposure to PBO synergist.ResultsLarval bioassay revealed that all the three populations tested with temephos were susceptible. Adult bioassays showed a good level of susceptibility toward both pyrethroids tested, 0.25% permethrin and 0.05% deltamethrin, with six out of 10 populations susceptible. However, two populations (Douala and Edéa) were resistant (deltamethrin [73.2–92.5% mortality], permethrin [2.6–76.3% mortality]). The resistance to 4% dichlorodiphenyltrichloroethane was observed in four out of 10 populations tested (16.8–87.1% mortality). Resistance was also reported to carbamates including 0.1% propoxur (60.8–87.1% mortality) and to 0.1% bendiocarb (82.9% mortality). All populations tested were fully susceptible to 1% fenitrothion. A partial recovery of susceptibility was observed in the pyrethroid resistant population of Douala after pre-exposed to PBO suggesting the implication of cytochrome P450 monoxygenases permethrin resistance. Genotyping and sequencing detected the F1534C kdr mutation in the two pyrethroid resistant locations of Edéa and Douala, with allelic frequency of 3.3% and 33.3% respectively. However, the high genetic diversity of the sodium channel gene supports the recent introduction of this mutation in Cameroon.ConclusionsThis study revealed the contrasting resistance profiles to insecticides of Ae. aegypti populations in Cameroon suggesting that, instead of a unique nationwide control approach, a regionally adapted strategy will be needed to control this vector. The localised distribution of the F1534C kdr mutation supports this region-specific control strategy.

【 授权许可】

CC BY