Laboratoire d'Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, BP 5005 Dakar, Senegal.
Centre for Research in Infectious Diseases (CRID) BP 13591, Yaoundé, Cameroon.
Genes (Basel). 2020 Nov 25;11(12):1403. doi: 10.3390/genes11121403.
The emergence and spread of insecticide resistance among the main malaria vectors is threatening the effectiveness of vector control interventions in Senegal. The main drivers of this resistance in the complex (e.g., and ) remains poorly characterized in Senegal. Here we characterized the main target site and metabolic resistances mechanisms among the and populations from their sympatric and allopatric or predominance area in Senegal. Larvae and pupae of s.l. were collected, reared to adulthood, and then used for insecticides susceptibility and synergist assays using the WHO (World Health Organisation) test kits for adult mosquitoes. The TaqMan method was used for the molecular characterization of the main target site insecticide resistance mechanisms (Vgsc-1014F, Vgsc-1014S, N1575Y and G119S). A RT-qPCR (Reverse Transcriptase-quantitative Polymerase Chaine Reaction) was performed to estimate the level of genes expression belonging to the CYP450 (Cytochrome P450) family. infection rate was investigated using TaqMan method. High levels of resistance to pyrethroids and DDT and full susceptibility to organophosphates and carbamates where observed in all three sites, excepted a probable resistance to bendiocarb in Kedougou. The L1014F, L1014S, and N1575Y mutations were found in both species. Pre-exposure to the PBO (Piperonyl butoxide) synergist induced a partial recovery of susceptibility to permethrin and full recovery to deltamethrin. Subsequent analysis of the level of genes expression, revealed that the and genes were over-expressed in wild-resistant mosquitoes compared to the reference susceptible strain (Kisumu), suggesting that both the metabolic resistance and target site mutation involving mutations are likely implicated in this pyrethroid resistance. The presence of both target-site and metabolic resistance mechanisms in highly pyrethroid-resistant populations of s.l. from Senegal threatens the effectiveness and the sustainability of the pyrethroid-based tools and interventions currently deployed in the country. The mutation is widely widespread in sympatric population. PBO or Duo nets and IRS (Indoor Residual Spraying) with organophosphates could be used as an alternative measure to sustain malaria control in the study area.
主要疟疾传播媒介中的杀虫剂耐药性的出现和传播正在威胁塞内加尔病媒控制干预措施的有效性。在塞内加尔，这种耐药性的主要驱动因素（例如， 和 ）在复杂的生态系统中仍然特征不明确。在这里，我们描述了来自塞内加尔同域和异域或优势区域的 和 种群的主要靶标和代谢抗性机制。收集了 s.l. 的幼虫和蛹，将其饲养至成虫，然后使用世界卫生组织（WHO）成蚊测试试剂盒进行杀虫剂敏感性和增效剂测定。使用 TaqMan 方法对主要靶标杀虫剂抗性机制（Vgsc-1014F、Vgsc-1014S、N1575Y 和 G119S）进行分子特征描述。进行 RT-qPCR（逆转录定量聚合酶链式反应）以估计属于细胞色素 P450（CYP450）家族的基因表达水平。使用 TaqMan 方法调查 感染率。在所有三个地点都观察到对拟除虫菊酯和滴滴涕的高水平抗性，以及对有机磷和氨基甲酸酯的完全敏感性，除了在凯杜古可能对苯氧威有抗药性。在这两个物种中都发现了 L1014F、L1014S 和 N1575Y 突变。预先暴露于增效剂 PBO（胡椒基丁醚）可使拟除虫菊酯的敏感性部分恢复，而对溴氰菊酯的敏感性完全恢复。随后对基因表达水平进行分析，结果表明，与参考敏感株（基苏木）相比，野生抗性蚊子中 和 基因过度表达，这表明代谢抗性和涉及 突变的靶标突变都可能参与这种拟除虫菊酯抗性。来自塞内加尔的高度拟除虫菊酯抗性 s.l. 种群中存在靶标和代谢抗性机制，这威胁到该国目前部署的基于拟除虫菊酯的工具和干预措施的有效性和可持续性。 突变在同域种群中广泛存在。在研究区域，可以使用增效剂 PBO 或 Duo 网和有机磷类的室内滞留喷洒（IRS）作为替代措施来维持疟疾控制。
