title: Field-collected permethrin-resistant Aedes aegypti from central Thailand contain point mutations in the domain IIS6 of the sodium channel gene (KDR).
abstract: One of the mechanisms responsible for pyrethroid resistance in mosquitoes is mutations in domain IIS6 of voltage-gated sodium channel gene (kdr). Aedes aegypti larvae were collected from the central provinces of Thailand (Bangkok, Prachin Buri and Ratchaburi) and colonized until they became adults. Partial fragment of kdr of permethrin-resistant mosquitoes were amplified by RT-PCR and sequenced. Among the four nucleotide mutations detected, two mutations resulted in two amino acid substitutions, S(TCC) 989 P(CCC) and V(GTA)1016 G(GGA). Among 94 permethrin-resistant mosquitoes, the SS genotype (SS/VV) was found to predominate (n = 74), followed by SR (SP/VG) (n = 15) and RR (PP/ GG) genotypes (n = 5), with the resistant allele frequency ranging from 0.03 to 0.17. As pyrethroid insecticides are currently being advocated for use in Thailand, investigations of pyrethroid resistance in other regions of the country are needed to prevent potential cross-resistance among different types of insecticides.
authors: Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. raweewan.sri@mahidol.ac.th
authors: Raweewan
authors: R
authors: Srisawat
authors: Narumon
authors: N
authors: Komalamisra
authors: Chamnarn
authors: C
authors: Apiwathnasorn
authors: Pungasem
authors: P
authors: Paeporn
authors: Sittiruk
authors: S
authors: Roytrakul
authors: Yupha
authors: Y
authors: Rongsriyam
authors: Yuki
authors: Y
authors: Eshita
mesh_terms: D000330:Aedes / Q000187:drug effects / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D007305:Insecticide Resistance / Q000187:drug effects / Q000235:genetics*; D007306:Insecticides / Q000494:pharmacology; D007814:Larva / Q000187:drug effects / Q000235:genetics; D009154:Mutation / Q000187:drug effects; D026023:Permethrin / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013785:Thailand; D062546:Voltage-Gated Sodium Channel beta Subunits / Q000187:drug effects / Q000235:genetics*
chemical_list: D007306:Insecticides; D062546:Voltage-Gated Sodium Channel beta Subunits; D026023:Permethrin