Pyrethroid resistance in Aedes aegypti from Grand Cayman.
The Grand Cayman population of Aedes aegypti is highly resistant to DDT and pyrethroid insecticides. Glutathione transferase, cytochrome P450, and esterase levels were increased in the Grand Cayman population relative to a susceptible laboratory strain, but synergist studies did not implicate elevated insecticide detoxification as a major cause of resistance. The role of target site resistance was therefore investigated. Two substitutions in the voltage-gated sodium channel were identified, V1016I in domain II, segment 6 (IIS6) (allele frequency = 0.79) and F1534C in IIIS6 (allele frequency = 0.68). The role of the F1534C mutation in conferring resistance to insecticides has not been previously established and so a tetraplex polymerase chain reaction assay was designed and used to genotype mosquitoes that had been exposed to insecticides. The F1534C mutation was strongly correlated with resistance to DDT and permethrin.
Harris
Angela F
AF
The Mosquito Research and Control Unit, Grand Cayman, Cayman Islands, British West Indies. angela.harris@gov.ky
Rajatileka
Shavanthi
S
Ranson
Hilary
H
D000330:Aedes / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001681:Biological Assay; D003634:DDT / Q000494:pharmacology; D005260:Female; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007303:Insect Vectors / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D011722:Pyrethrins / Q000494:pharmacology*; D015222:Sodium Channels / Q000235:genetics; D014900:West Indies
D019476:Insect Proteins; D007306:Insecticides; D011722:Pyrethrins; D015222:Sodium Channels; D003634:DDT