Colorado State University, Department of Microbiology, Immunology and Pathology, 1692 Campus Delivery, Fort Collins, CO 80523, USA.
J Med Entomol. 2012 Mar;49(2):356-63. doi: 10.1603/me11164.
Seven different strains of Aedes aegypti (L.), including a genetically diverse laboratory strain, three laboratory-selected permethrin-resistant strains, a standard reference strain, and two recently colonized strains were fed on human blood containing various concentrations of ivermectin. Ivermectin reduced adult survival, fecundity, and hatch rate of eggs laid by ivermectin-treated adults in all seven strains. The LC50 of ivermectin for adults and the concentration that prevented 50% of eggs from hatching was calculated for all strains. Considerable variation in adult survival after an ivermectin-bloodmeal occurred among strains, and all three permethrin-resistant strains were significantly less susceptible to ivermectin than the standard reference strain. The hatch rate after an ivermectin bloodmeal was less variable among strains, and only one of the permethrin-resistant strains differed significantly from the standard reference strain. Our studies suggest that ivermectin induces adult mortality and decreases the hatch rate of eggs through different mechanisms. A correlation analysis of log-transformed LC50 among strains suggests that permethrin and ivermectin cross-resistance may occur.
七种不同品系的埃及伊蚊（L.），包括遗传多样性的实验室品系、三种实验室选择的拟除虫菊酯抗性品系、标准参考品系和两种最近殖民的品系，被喂食含有不同浓度伊维菌素的人血。伊维菌素降低了所有七种品系中经伊维菌素处理的成虫的存活率、繁殖力和产卵孵化率。计算了所有品系成虫的伊维菌素 LC50 和 50%卵不能孵化的浓度。在伊维菌素-血餐后，成虫的存活率在不同品系之间存在很大差异，所有三种拟除虫菊酯抗性品系对伊维菌素的敏感性明显低于标准参考品系。伊维菌素血餐后的孵化率在品系之间变化较小，只有一种拟除虫菊酯抗性品系与标准参考品系有显著差异。我们的研究表明，伊维菌素通过不同的机制诱导成虫死亡并降低卵的孵化率。对品系间对数转换 LC50 的相关分析表明，拟除虫菊酯和伊维菌素可能存在交叉抗性。
