title: Involvement of metabolic resistance and F1534C kdr mutation in the pyrethroid resistance mechanisms of Aedes aegypti in India.
abstract: Pesticide resistance poses a serious problem for worldwide mosquito control programs. Resistance to insecticides can be caused by an increased metabolic detoxification of the insecticide and/or by target site insensitivity. In the present study, we estimated the tolerance of Indian Aedes aegypti populations using adult bioassays that revealed high resistance levels of the field populations to permethrin (RR-6, 5.8 and 5.1 folds) compared to our susceptible population. Enzymatic assays revealed increased activities of glutathione S-transferase and carboxylesterase enzymes in the field populations comparatively to the susceptible population. PBO synergist assays did not confirm that cytochrome P450 monooxygenase metabolic detoxification acted as a major cause of resistance. Hence the role of target site resistance was therefore investigated. A single substitution Phe1534Cys in the voltage gated sodium channel was found in domain III, segment 6 (III-S6) of the resistance populations (allele frequency=0.59, 0.51 and 0.47) suggesting its potential role in permethrin resistance in A. aegypti.
authors.affiliation: Molecular Entomology Laboratory, Department of Biotechnology, School of Biosciences, Periyar University, Periyar Palkalai Nagar, Salem 636011, Tamil Nadu, India.
authors.forename: R
authors.initials: R
authors.lastname: Muthusamy
authors.affiliation: Molecular Entomology Laboratory, Department of Biotechnology, School of Biosciences, Periyar University, Periyar Palkalai Nagar, Salem 636011, Tamil Nadu, India. Electronic address: skentomol@gmail.com.
authors.forename: M S
authors.initials: MS
authors.lastname: Shivakumar
mesh_terms: D000330:Aedes / Q000201:enzymology / Q000235:genetics*; D000818:Animals; D043182:Carboxylesterase / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005787:Gene Frequency; D005982:Glutathione Transferase / Q000378:metabolism; D007194:India; D007305:Insecticide Resistance / Q000235:genetics* / Q000502:physiology; D007306:Insecticides; D009032:Mosquito Control; D009154:Mutation; D026023:Permethrin; D011722:Pyrethrins; D061566:Voltage-Gated Sodium Channels / Q000235:genetics*
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D061566:Voltage-Gated Sodium Channels; D026023:Permethrin; D003577:Cytochrome P-450 Enzyme System; D005982:Glutathione Transferase; D043182:Carboxylesterase
keywords: Aedes aegypti; Detoxification enzymes; Permethrin resistance; Synergist; Target site insensitivity