Université Montpellier 2, UMR CNRS 5554, Institut des Sciences de l'Evolution, Génétique de l'Adaptation, Place Eugène Bataillon, Montpellier 05, France.
Insect Biochem Mol Biol. 2010 Apr;40(4):317-24. doi: 10.1016/j.ibmb.2010.02.005. Epub 2010 Feb 25.
Resistance to insecticides was monitored on Culex pipiens quinquefasciatus mosquitoes collected in twelve localities of La Réunion, a geographically isolated island of the Indian Ocean. This mosquito is of medical concern in the region as a known vector for filariasis and a potential vector for West Nile and Rift Valley Fever viruses. Our bioassays indicated the presence of resistance to all tested insecticides, i.e. organochlorides, organophosphates and pyrethroids. A molecular investigation revealed a higher frequency of resistance genes in the coastal areas compared to elevated rural sites, probably reflecting the different nature of insecticide pressures together with the genetic cost of resistance alleles. A simple molecular test was developed to detect Rdl allele, encoding a gamma-aminobutyric acid (GABA) receptor resistant to dieldrin. Unexpectedly high Rdl frequencies were recorded over the whole island, despite this insecticide having been banned for over 15 years. This resistant allele was also detected for the first time in two samples of Aedes albopictus, a species recently involved in severe Chikungunya epidemics on the island. Rdl selection in these two mosquito species discloses current insecticide pressures in urban areas, from unknown origins, that should be taken into account to develop vector control strategies.
在印度洋的一个地理隔离岛上留尼汪岛的 12 个地方采集的库蚊中监测到对杀虫剂的抗药性。由于这种蚊子是已知的丝虫病传播媒介，也是西尼罗河病毒和裂谷热病毒的潜在传播媒介，因此该地区对其非常关注。我们的生物测定表明，所有测试的杀虫剂，即有机氯、有机磷和拟除虫菊酯都存在抗药性。分子调查显示，沿海地区的抗性基因频率高于高地农村地区，这可能反映了不同性质的杀虫剂压力以及抗性等位基因的遗传代价。开发了一种简单的分子检测方法来检测编码对狄氏剂有抗性的γ-氨基丁酸（GABA）受体的 Rdl 等位基因。尽管这种杀虫剂已经被禁止使用超过 15 年，但整个岛上都记录到了出人意料的高 Rdl 频率。该抗性等位基因也首次在两种白纹伊蚊样本中被发现，这种物种最近在岛上严重的基孔肯雅热疫情中发挥了作用。这两种蚊子中 Rdl 的选择揭示了当前城市地区来自未知来源的杀虫剂压力，应考虑这些压力来制定病媒控制策略。
