Abstract:
Evaluating the susceptibility of malaria vectors to the new WHO-recommended products is a key step before large-scale deployment. We mapped the susceptibility profile of Anopheles funestus to neonicotinoids across Africa and established the diagnostic doses of acetamiprid and imidacloprid with acetone + MERO as solvent. Indoor resting An. funestus were collected in 2021 in Cameroon, Malawi, Ghana and Uganda. Susceptibility to clothianidin, imidacloprid and acetamiprid was evaluated using CDC bottle assays and offsprings of the field-caught adults. The L119F-GSTe2 marker was genotyped to assess the potential cross-resistance between clothianidin and this DDT/pyrethroid-resistant marker. Mosquitoes were susceptible to the three neonicotinoids diluted in acetone + MERO, whereas low mortality was noticed with ethanol or acetone alone. The doses of 6 µg/mL and 4 µg/mL were established as diagnostic concentrations of imidacloprid and acetamiprid, respectively, with acetone + MERO. Pre-exposure to synergists significantly restored the susceptibility to clothianidin. A positive correlation was observed between L119F-GSTe2 mutation and clothianidin resistance with the homozygote resistant mosquitoes being more able to survive than heterozygote or susceptible. This study revealed that An. funestus populations across Africa are susceptible to neonicotinoids, and as such, this insecticide class could be effectively implemented to control this species using IRS. However, potential cross-resistance conferred by GSTe2 calls for regular resistance monitoring in the field.
摘要:
评估疟疾病媒对世卫组织推荐的新产品的敏感性是大规模部署之前的关键步骤。我们绘制了整个非洲按蚊对新烟碱的敏感性图,并确定了以丙酮MERO为溶剂的啶虫脒和吡虫啉的诊断剂量。室内休息。Funestus于2021年在喀麦隆收集,马拉维,加纳和乌干达。对噻虫胺的敏感性,使用CDC瓶测定法和野外捕获的成年人的后代评估了吡虫啉和啶虫脒。对L119F-GSTe2标记进行基因分型,以评估噻虫胺和该DDT/拟除虫菊酯抗性标记之间的潜在交叉抗性。蚊子对用丙酮+MERO稀释的三种新烟碱敏感,而单独使用乙醇或丙酮时死亡率低。将6µg/mL和4µg/mL的剂量确定为吡虫啉和啶虫脒的诊断浓度,分别,丙酮+MERO。预暴露于增效剂可显着恢复对噻虫胺的敏感性。在L119F-GSTe2突变与clothianidin抗性之间观察到正相关,纯合子抗性蚊子比杂合子或易感蚊子更能够生存。这项研究表明,An。非洲各地的Funestus人群容易受到新烟碱的影响,因此,使用IRS可以有效地实施这种杀虫剂类别来控制该物种。然而,GSTe2赋予的潜在交叉电阻要求在现场进行定期电阻监测。