Data from: Blocking the evolution of insecticide-resistant malaria vectors with a microsporidian

Finding a way to block the evolution insecticide-resistance would be a major breakthrough for the control of malaria. We suggest that this may be possible by introducing a stress into mosquito populations that restores the sensitivity of genetically resistant mosquitoes and that decreases their longevity when they are not exposed to insecticide. We use a mathematical model to show that, despite the intense selection pressure imposed by insecticides, moderate levels of stress might tip the evolutionary balance between costs and benefits of resistance towards maintaining sensitivity. Our experimental work with the microsporidian parasite Vavraia culicis infecting two lines of resistant mosquitoes and a sensitive line suggests that it may indeed be possible to stress the mosquitoes in the required way. The mortality of resistant mosquitoes 24h after exposure to the insecticide was up to 8.8 times higher in infected than in uninfected ones; if mosquitoes were not exposed to the insecticide, resistant mosquitoes infected by the microsporidian lived about half as long as uninfected ones and insecticide-sensitive mosquitoes (with or without the parasite). Our results suggest that biopesticides or other insecticides that interfere with the expression of resistance may help to manage insecticide-resistance in programs of malaria control.

找到阻断杀虫剂抗药性演化的方法，将成为疟疾防控领域的重大突破。我们提出，可通过向蚊子种群引入一种胁迫因子实现这一目标：该因子既能恢复遗传抗性蚊子的杀虫剂敏感性，又能在蚊子未接触杀虫剂时缩短其寿命。我们借助数学模型证明，尽管杀虫剂施加了极强的选择压力，适度的胁迫或许能扭转抗性演化的代价与收益间的进化平衡，使种群维持对杀虫剂的敏感性。我们以感染微孢子虫（microsporidian）Vavraia culicis的两种抗性蚊子品系与一种敏感品系为对象开展实验，结果表明，按预期方式对蚊子施加胁迫确实可行：接触杀虫剂后24小时，受感染的抗性蚊子的死亡率最高可达未感染个体的8.8倍；而在未接触杀虫剂的情况下，受感染的抗性蚊子的寿命仅约为未感染个体以及杀虫剂敏感蚊子（无论是否感染该寄生虫）的一半。本研究结果提示，可通过干扰抗性表达的生物杀虫剂或其他药剂，助力疟疾防控项目中的杀虫剂抗药性管理工作。