Martinez-Torres D, Chandre F, Williamson M S, Darriet F, Bergé J B, Devonshire A L, Guillet P, Pasteur N, Pauron D
Laboratoire de Biologie des Invertébrés, I.N.R.A., Antibes, France.
Insect Mol Biol. 1998 May;7(2):179-84. doi: 10.1046/j.1365-2583.1998.72062.x.
Pyrethroid-impregnated bednets are playing an increasing role for combating malaria, especially in stable malaria areas. More than 90% of the current annual malaria incidence (c. 500 million clinical cases with up to 2 million deaths) is in Africa where the major vector is Anopheles gambiae s.s. As pyrethroid resistance has been reported in this mosquito, reliable and simple techniques are urgently needed to characterize and monitor this resistance in the field. In insects, an important mechanism of pyrethroid resistance is due to a modification of the voltage-gated sodium channel protein recently shown to be associated with mutations of the para-type sodium channel gene. We demonstrate here that one of these mutations is present in certain strains of pyrethroid resistant A. gambiae s.s. and describe a PCR-based diagnostic test allowing its detection in the genome of single mosquitoes. Using this test, we found this mutation in six out of seven field samples from West Africa, its frequency being closely correlated with survival to pyrethroid exposure. This diagnostic test should bring major improvement for field monitoring of pyrethroid resistance, within the framework of malaria control programmes.
拟除虫菊酯浸渍蚊帐在抗击疟疾方面发挥着越来越重要的作用，尤其是在疟疾稳定流行地区。目前每年疟疾发病率的90%以上（约5亿例临床病例，多达200万人死亡）发生在非洲，主要病媒是冈比亚按蚊。由于已报道这种蚊子对拟除虫菊酯产生抗性，因此迫切需要可靠且简单的技术来在野外鉴定和监测这种抗性。在昆虫中，拟除虫菊酯抗性的一个重要机制是由于电压门控钠通道蛋白的修饰，最近发现这与对位型钠通道基因的突变有关。我们在此证明，这些突变之一存在于某些对拟除虫菊酯抗性的冈比亚按蚊品系中，并描述了一种基于PCR的诊断测试，可在单个蚊子的基因组中检测到该突变。使用该测试，我们在来自西非的七个野外样本中的六个中发现了这种突变，其频率与拟除虫菊酯暴露后的存活率密切相关。在疟疾控制计划的框架内，这种诊断测试应为拟除虫菊酯抗性的野外监测带来重大改进。
