Insects (May 2024)

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

DOI
https://doi.org/10.3390/insects15050358
Journal volume & issue
Vol. 15, no. 5
p. 358

Abstract

Read online

(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.

Keywords