Uddin Mohammad Mosleh, Islam Ashekul, Islam Md Sujan, Ekra Jannatul Efte, Watanabe Kozo
Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama 790-8577, Japan; Graduate School of Science and Engineering, Ehime University, Bunkyo-cho 3, Matsuyama, Ehime, Japan; Department of Biochemistry and Molecular Biology, Mawlana Bhashani Science and Technology University, Santosh, Tangail 1902, Bangladesh.
Department of Biochemistry and Molecular Biology, Mawlana Bhashani Science and Technology University, Santosh, Tangail 1902, Bangladesh.
Acta Trop. 2025 Sep;269:107736. doi: 10.1016/j.actatropica.2025.107736. Epub 2025 Jul 9.
Insecticide resistance in mosquito populations remains a formidable challenge for the control of vector-borne diseases, especially in developing countries such as Bangladesh. This study investigates known knockdown resistance (kdr) mutations associated with pyrethroid resistance in Aedes aegypti and Culex species mosquitoes collected from Dhaka and Tangail cities. Deltamethrin-based CDC-bottle bioassays showed that Aedes aegypti had resistance rates of 39.5 % at 1X and 3X concentrations, decreasing to 27.3 % at 5X. In contrast, the Culex pipiens complex showed resistance rates of 74 %, 65 %, 25 %, and 37 % at 1X, 3X, 5X, and 10X doses, respectively. Molecular identification via mitochondrial Cytochrome c Oxidase I (COI)- gene confirmed 100 % similarity to Aedes aegypti strains, while the Culex specimens clustered with the member of Culex pipiens species complex. Based on the Culex species-specific primer targeting acetylcholinesterase-2 (ace-2) gene, 16 out of 22 were identified as Culex quinquefasciatus. Genetic profiling of the VGSC gene revealed three notable kdr mutant patterns in Aedes aegypti: (1) 989PP + 1016GG, (2) 989PP + 1016GG + 1534CC, and (3) 989PP + 1016GG + 1534FC. Conversely, the Culex quinquefasciatus and the other member of Culex pipiens complex exhibited homozygous L1014F mutation across all samples. Intriguingly, the phenotypic resistance to deltamethrin in the bottle assay in both species suggests the influence of alternative resistance mechanisms. This study presents the first documented evidence in Bangladesh of three kdr mutations in Aedes aegypti and one in Culex quinquefasciatus/pipiens complex, providing a snapshot of the genetic landscape of insecticide resistance and underscoring the need for molecular surveillance.
蚊虫种群中的抗杀虫剂能力仍然是控制病媒传播疾病的一项艰巨挑战，在孟加拉国等发展中国家尤其如此。本研究调查了从达卡市和坦盖尔市采集的埃及伊蚊和库蚊属蚊子中已知的与拟除虫菊酯抗性相关的击倒抗性（kdr）突变。基于溴氰菊酯的疾控中心瓶式生物测定表明，埃及伊蚊在1倍和3倍浓度下的抗性率为39.5%，在5倍浓度下降至27.3%。相比之下，尖音库蚊复合组在1倍、3倍、5倍和10倍剂量下的抗性率分别为74%、65%、25%和37%。通过线粒体细胞色素c氧化酶I（COI）基因进行的分子鉴定证实与埃及伊蚊菌株有100%的相似性，而库蚊标本则与尖音库蚊物种复合组的成员聚类。基于针对乙酰胆碱酯酶-2（ace-2）基因的库蚊属特异性引物，22个样本中有16个被鉴定为致倦库蚊。电压门控钠离子通道（VGSC）基因的基因分析揭示了埃及伊蚊中三种显著的kdr突变模式：（1）989PP + 1016GG，（2）989PP + 1016GG + 1534CC，以及（3）989PP + 1016GG + 1534FC。相反，致倦库蚊和尖音库蚊复合组的其他成员在所有样本中均表现出纯合的L1014F突变。有趣的是，两种蚊子在瓶式试验中对溴氰菊酯的表型抗性表明存在其他抗性机制的影响。本研究提供了孟加拉国埃及伊蚊中三种kdr突变以及致倦库蚊/尖音库蚊复合组中一种kdr突变的首个文献证据，呈现了抗杀虫剂能力的遗传状况，并强调了分子监测的必要性。
