Muthusamy R, Shivakumar M S
Molecular Entomology Laboratory, Department of Biotechnology, School of Biosciences, Periyar University, Periyar Palkalai Nagar, Salem 636011, Tamil Nadu, India.
Molecular Entomology Laboratory, Department of Biotechnology, School of Biosciences, Periyar University, Periyar Palkalai Nagar, Salem 636011, Tamil Nadu, India.
Acta Trop. 2015 Aug;148:137-41. doi: 10.1016/j.actatropica.2015.04.026. Epub 2015 May 2.
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.
杀虫剂抗性给全球蚊虫控制项目带来了严重问题。对杀虫剂的抗性可能是由于杀虫剂代谢解毒增加和/或靶标位点不敏感所致。在本研究中，我们使用成虫生物测定法评估了印度埃及伊蚊种群的耐受性，结果显示与我们的敏感种群相比，野外种群对氯菊酯具有高抗性水平（抗性比分别为6、5.8和5.1倍）。酶活性测定表明，与敏感种群相比，野外种群中谷胱甘肽S -转移酶和羧酸酯酶的活性增加。PBO增效剂测定未证实细胞色素P450单加氧酶代谢解毒是抗性的主要原因。因此，我们研究了靶标位点抗性的作用。在抗性种群的结构域III第6节段（III - S6）的电压门控钠通道中发现了单个取代Phe1534Cys（等位基因频率分别为0.59、0.51和0.47），这表明其在埃及伊蚊对氯菊酯抗性中可能发挥作用。
