National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai 200025, China.
Chinese Center for Tropical Diseases Research, Shanghai 200025, China.
J Med Entomol. 2021 Jul 16;58(4):1839-1848. doi: 10.1093/jme/tjab048.
Gene mutations on target sites can be a valuable indicator of the status of insecticide resistance. Jeddah, a global commercial and major port-of-entry city, is bearing the brunt of dengue disease burden in Saudi Arabia. In the current study, six genotypes of three codon combinations (989, 1016, and 1534) were observed on voltage-gated sodium channel (VGSC) gene in Jeddah's Aedes aegypti population, with PGF/PGC as the dominant one. Two types of introns between exon 20 and 21 on VGSC have been identified for the first time in Ae. aegypti in Saudi Arabia. Statistical and phylogenetic analyses showed that the intron type was significantly associated with the 1016 allele and may reflect the history of insecticide treatment in different continents. In addition, fixation of the L1014F allele on VGSC and G119S on acetylcholinesterase 1 gene was detected in local Culex quinquefasciatus populations, with frequencies of 95.24 and 100%, respectively. To the best of our knowledge, this is the first report of resistant-associated mutations in field-caught Cx. quinquefasciatus in Saudi Arabia. The high prevalence of insecticide resistance gene mutations in local primary mosquito vector species highlights the urgent need to carry out comprehensive insecticide resistance surveillance in Saudi Arabia.
目标位点的基因突变可以作为昆虫抗药性状况的一个有价值的指标。吉达是一个全球性的商业和主要港口城市，是沙特阿拉伯登革热疾病负担的主要承受者。在本研究中，观察到吉达埃及伊蚊种群的电压门控钠离子通道（VGSC）基因的三个密码子组合（989、1016 和 1534）的六个基因型，PGF/PGC 是主要的基因型。首次在沙特阿拉伯的埃及伊蚊中发现了 VGSC 第 20 和 21 外显子之间的两种内含子类型。统计和系统发育分析表明，内含子类型与 1016 等位基因显著相关，可能反映了不同大陆杀虫剂处理的历史。此外，在当地的库蚊种群中检测到 VGSC 上的 L1014F 等位基因和乙酰胆碱酯酶 1 基因上的 G119S 的固定，频率分别为 95.24%和 100%。据我们所知，这是沙特阿拉伯首次在野外捕获的库蚊中发现与抗药性相关的突变。当地主要蚊虫媒介物种中抗药性基因突变的高流行率突出表明，迫切需要在沙特阿拉伯开展全面的杀虫剂抗药性监测。
