Mutated sodium channel genes and elevated monooxygenases are found in pyrethroid resistant populations of Sri Lankan malaria vectors

• Published in: Pesticide biochemistry and physiology Vol. 88; no. 1; pp. 108 - 113
• Main Authors: Karunaratne, S.H.P.P., Hawkes, N.J., Perera, M.D.B., Ranson, H., Hemingway, J.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.05.2007; Elsevier
• Subjects: Anopheles culicifacies; Anopheles subpictus; Biological and medical sciences; cross resistance; cyfluthrin; cypermethrin; enzymes; etofenprox; Fundamental and applied biological sciences. Psychology; genes; insect pests; insect vectors; insecticide resistance; kdr; lambda-cyhalothrin; malaria; Malaria vectors; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; molecular sequence data; monooxygenase; Monooxygenases; mutation; nucleotide sequences; permethrin; Phytopathology. Animal pests. Plant and forest protection; Pyrethroid resistance; sequence analysis; sodium channels; Vectors. Intermediate hosts; Sri Lanka; Asia; South Asia; kdr; Pyrethroid resistance; Malaria vectors; Anopheles culicifacies; Anopheles subpictus; Monooxygenases; Protozoal disease; Insecta; Tropical zone; Pyrethroids; Ionic channel; Gene; Sodium ion; Population; Vector; Malaria; Enzyme; Pesticides; Inorganic ion; Parasitosis; Infection; Oxygenase; Resistance; Inorganic cation; Sensitivity resistance; Arthropoda; Culicidae; Oxidoreductases; Mutation; Invertebrata; Diptera
• ISSN: 0048-3575; 1095-9939
• DOI: 10.1016/j.pestbp.2006.10.001

The present status of pyrethroid resistance in vectors of malaria; Anopheles culicifacies and Anopheles subpictus, was tested in two malarious Districts, Anuradhapura and Trincomalee, of Sri Lanka. Both species were resistant to permethrin and susceptible to cypermethrin and cyfluthrin. An. subpictus were resistant to deltamethrin. λ-Cyhalothrin and etofenprox resistance was shown only by Anuradhapura An. subpictus. Although there were no differences among the populations for esterase and glutathione S-transferase activities, increased monooxygenase levels were found among Trincomalee populations. The voltage-gated sodium channel gene, the target site gene of pyrethroids, was partially sequenced to screen for mutations previously associated with insecticide resistance. The classic leucine to phenylalanine substitution, TTA to TTT, was detected in An. subpictus. It appears that both kdr type and monooxygenase resistance underlie pyrethroid resistance in these two malaria vectors of Sri Lanka.