Beijing Research Center for Preventive Medicine, Beijing Center for Disease Control and Prevention, Beijing, 100013, China.
State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
Parasit Vectors. 2019 Apr 24;12(1):180. doi: 10.1186/s13071-019-3423-x.
Aedes albopictus (Skuse) is an important vector of chikungunya, dengue, yellow fever and Zika viruses. In the absence of anti-viral medication and with limited availability of a commercial vaccine for public health use, vector control remains an effective means for reducing Aedes-borne disease morbidity. Knowledge about genetic mutations associated with insecticide resistance (IR) is a prerequisite for developing rapid resistance diagnosis, and the distribution and frequency of IR conferring mutations is important information for making smart vector control decisions.
Partial DNA sequences of domain II and domain III of Ae. albopictus voltage gated sodium channel (VGSC) gene were amplified from a total of 426 individuals, collected from 17 sites in the Beijing municipality. These DNA fragments were sequenced to discover the possible genetic mutations mediating knockdown resistance (kdr) to pyrethroids. The frequency and distribution of kdr mutations were assessed in the 17 Ae. albopictus populations. The origin of kdr mutations was investigated by haplotype clarification and phylogenetic analysis.
Sequence alignments revealed the existence of multiple mutations (V1016G, I1532T, F1534S and F1534L) in VGSC. The highest frequency of the mutant 1016G allele (0.647) was found in Haidian, while 1016G was not detected in Huai Rou, Yan Qing, Ping Gu and Shun Yi. The frequency of 1532T was highest (0.537) in the population from the Olympic Forest Park (OFP, Chao Yang District), but not detectable in Huai Rou and Mi Yun. Two mutations were observed at codon 1534 with different distribution patterns: 1534L was only found in Tong Zhou (TZ) with a frequency of 0.017, while 1534S was distributed in TZ, OFP, Fang Shan, Da Xing and Shi Jing Shan with frequencies ranging from 0.019 (OFP) to 0.276 (TZ). One 1016G, one 1532T, one 1534L and two 1534S haplotypes were identified.
Multiple mutations (V1016G, I1532T, F1534L/S) in VGSC were found in Ae. albopictus in Beijing. This represents the first report of V1016G in Ae. albopictus. Sequence alignment and phylogenetic analysis revealed multiple origins of 1534S. The spatial heterogeneity in distribution and frequency of kdr mutations calls for a site-specific strategy for the monitoring of insecticide resistance. The relatively high frequencies of V1016G warn of a risk of pyrethroid resistance in mosquitoes in the urban zones.
白纹伊蚊（Skuse）是基孔肯雅热、登革热、黄热病和寨卡病毒的重要传播媒介。在没有抗病毒药物且公众可获得的商业疫苗有限的情况下，病媒控制仍然是降低蚊媒疾病发病率的有效手段。了解与杀虫剂抗性（IR）相关的遗传突变是快速抗性诊断的前提，IR 赋予突变的分布和频率是做出明智病媒控制决策的重要信息。
从北京市 17 个地点采集的 426 只白纹伊蚊个体中扩增了白纹伊蚊电压门控钠通道（VGSC）基因的 II 域和 III 域的部分 DNA 序列。对这些 DNA 片段进行测序以发现可能介导拟除虫菊酯击倒抗性（kdr）的遗传突变。评估了 17 个白纹伊蚊种群中的 kdr 突变的频率和分布。通过单倍型澄清和系统发育分析研究了 kdr 突变的起源。
序列比对显示 VGSC 中存在多个突变（V1016G、I1532T、F1534S 和 F1534L）。1016G 等位基因的最高突变频率（0.647）在海淀区发现，而怀柔、延庆、平谷和顺义则未检测到 1016G。1532T 的频率最高（0.537）在朝阳区奥林匹克森林公园（OFP）的种群中，但在怀柔和密云则无法检测到。1534 密码子观察到两个突变，分布模式不同：1534L 仅在通州（TZ）发现，频率为 0.017，而 1534S 分布在 TZ、OFP、房山、大兴和石景山，频率范围为 0.019（OFP）至 0.276（TZ）。鉴定出一个 1016G、一个 1532T、一个 1534L 和两个 1534S 单倍型。
在北京的白纹伊蚊中发现了 VGSC 中的多个突变（V1016G、I1532T、F1534L/S）。这是首次在白纹伊蚊中发现 V1016G。序列比对和系统发育分析显示 1534S 有多个起源。kdr 突变的空间异质性分布和频率需要针对杀虫剂抗性进行特定地点的监测策略。V1016G 的相对高频率警告城市地区蚊子对拟除虫菊酯的抗性风险。
