Metabolic Resistance and Not Voltage-Gated Sodium Channel Gene Mutation Is Associated with Pyrethroid Resistance of <i>Aedes albopictus</i> (Skuse, 1894) from Cambodia
Sébastien Marcombe,
Bros Doeurk,
Phoutmany Thammavong,
Tuba Veseli,
Christian Heafield,
Molly-Ann Mills,
Sedra Kako,
Marcelly Ferreira Prado,
Shakira Thomson,
Saffron Millett,
Timothy Hill,
Imogen Kentsley,
Shereena Davies,
Geethika Pathiraja,
Ben Daniels,
Lucianna Browne,
Miranda Nyamukanga,
Jess Harvey,
Lyranne Rubinstein,
Chloe Townsend,
Zack Allen,
Christopher Davey-Spence,
Adina Hupi,
Andrew K. Jones,
Sebastien Boyer
Affiliations
Sébastien Marcombe
Medical Entomology and Vector-borne Diseases Laboratory, Institut Pasteur du Laos, Ministry of Health, Vientiane P.O. Box 3560, Laos
Bros Doeurk
Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, Phnom Penh P.O. Box 983, Cambodia
Phoutmany Thammavong
Medical Entomology and Vector-borne Diseases Laboratory, Institut Pasteur du Laos, Ministry of Health, Vientiane P.O. Box 3560, Laos
Tuba Veseli
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Christian Heafield
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Molly-Ann Mills
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Sedra Kako
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Marcelly Ferreira Prado
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Shakira Thomson
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Saffron Millett
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Timothy Hill
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Imogen Kentsley
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Shereena Davies
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Geethika Pathiraja
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Ben Daniels
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Lucianna Browne
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Miranda Nyamukanga
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Jess Harvey
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Lyranne Rubinstein
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Chloe Townsend
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Zack Allen
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Christopher Davey-Spence
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Adina Hupi
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Andrew K. Jones
Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK
Sebastien Boyer
Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, Phnom Penh P.O. Box 983, Cambodia
(1) Background: In Cambodia, Aedes albopictus is an important vector of the dengue virus. Vector control using insecticides is a major strategy implemented in managing mosquito-borne diseases. Resistance, however, threatens to undermine the use of insecticides. In this study, we present the levels of insecticide resistance of Ae. albopictus in Cambodia and the mechanisms involved. (2) Methods: Two Ae. albopictus populations were collected from the capital, Phnom Penh city, and from rural Pailin province. Adults were tested with diagnostic doses of malathion (0.8%), deltamethrin (0.03%), permethrin (0.25%), and DDT (4%) using WHO tube assays. Synergist assays using piperonyl butoxide (PBO) were implemented before the pyrethroid assays to detect the potential involvement of metabolic resistance mechanisms. Adult female mosquitoes collected from Phnom Penh and Pailin were tested for voltage-gated sodium channel (VGSC) kdr (knockdown resistance) mutations commonly found in Aedes sp.-resistant populations throughout Asia (S989P, V1016G, and F1534C), as well as for other mutations (V410L, L982W, A1007G, I1011M, T1520I, and D1763Y). (3) Results: The two populations showed resistance against all the insecticides tested (vgsc gene showed a lack of kdr mutations known to be associated with pyrethroid resistance. However, four novel non-synonymous mutations (L412P/S, C983S, Q1554STOP, and R1718L) and twenty-nine synonymous mutations were detected. It remains to be determined whether these mutations contribute to pyrethroid resistance. (4) Conclusions: Pyrethroid resistance is occurring in two Ae. albopictus populations originating from urban and rural areas of Cambodia. The resistance is likely due to metabolic resistance specifically involving P450s monooxygenases. The levels of resistance against different insecticide classes are a cause for concern in Cambodia. Alternative tools and insecticides for controlling dengue vectors should be used to minimize disease prevalence in the country.
