Kouadio France-Paraudie A, Sika Angèle N, Fodjo Behi K, Sadia Christabelle G, Oyou Sébastien K, Ouattara Allassane F, Mouhamadou Chouaïbou S
Environment and Health, Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, 01 BP 1303 Abidjan 01, Cote d'Ivoire.
Natural Sciences, Université Nangui Abrogoua, Abidjan, 02 BP 801 Abidjan 02, Cote d'Ivoire.
Wellcome Open Res. 2023 Jun 27;8:118. doi: 10.12688/wellcomeopenres.19126.2. eCollection 2023.
The indiscriminate use of insecticides in agriculture and public health lead to a selection of resistance mechanisms in malaria vectors compromising vector control tools and strategies. This study investigated the metabolic response in the -L995F Tiassalé resistance strain after long-term exposure of larvae and adults to deltamethrin insecticide. -L995F Tiassalé strain larvae were exposed over 20 generations to deltamethrin (LS) and adults to PermaNet 2.0 (AS) and combining exposure at larvae and adult stages (LAS) and compared to unexposed (NS) group. All four groups were subjected to the standard World Health Organization (WHO) susceptibility tube tests using deltamethrin (0.05%), bendiocarb (0.1%) and malathion (5%). -L995F/S ( mutation frequency was screened using multiplex assays based on Taqman real-time polymerase chain reaction (PCR) method. Additionally, expression levels of detoxification enzymes associated to pyrethroid resistance, including CYP4G16, CYP6M2, CYP6P1, CYP6P3, CYP6P4, CYP6Z1 and CYP9K1, and glutathione S-transferase GSTe2 were measured. Our results indicated that deltamethrin resistance was a response to insecticide selection pressure in LS, AS and LAS groups, while susceptibility was observed in NS group. The vectors showed varied mortality rates with bendiocarb and full susceptibility to malathion throughout the selection with LS, AS and LAS groups. -L995F mutation stayed at high allelic frequency level in all groups with a frequency between 87% and 100%. Among the overexpressed genes, CYP6P4 gene was the most overexpressed in LS, AS and LAS groups. Long-term exposure of larvae and adults of -L995F resistant- Tiassalé strain to deltamethrin and PermaNet 2.0 net induced resistance to deltamethrin under a significant effect of cytochromes P450 detoxification enzymes. These outcomes highlight the necessity of investigating metabolic resistance mechanisms in the target population and not solely resistance mechanisms prior the implementation of vector control strategies for a better impact.
农业和公共卫生领域中杀虫剂的滥用导致疟疾病媒产生了多种抗性机制，这对病媒控制工具和策略构成了威胁。本研究调查了-L995F 蒂亚萨莱抗性品系的幼虫和成虫长期接触溴氰菊酯杀虫剂后的代谢反应。-L995F 蒂亚萨莱品系的幼虫连续 20 代接触溴氰菊酯（LS），成虫接触长效蚊帐 PermaNet 2.0（AS），并结合幼虫和成虫阶段的联合接触（LAS），并与未接触组（NS）进行比较。所有四组均使用溴氰菊酯（0.05%）、残杀威（0.1%）和马拉硫磷（5%）进行标准的世界卫生组织（WHO）药敏管试验。使用基于 Taqman 实时聚合酶链反应（PCR）方法的多重检测筛选-L995F/S （突变频率。此外，还测量了与拟除虫菊酯抗性相关的解毒酶的表达水平，包括 CYP4G16、CYP6M2、CYP6P1、CYP6P3、CYP6P4、CYP6Z1 和 CYP9K1，以及谷胱甘肽 S-转移酶 GSTe2。我们的结果表明，溴氰菊酯抗性是 LS、AS 和 LAS 组对杀虫剂选择压力的反应，而 NS 组表现出敏感性。在 LS、AS 和 LAS 组的整个选择过程中，病媒对残杀威的死亡率各不相同，对马拉硫磷完全敏感。-L995F 突变在所有组中均保持在高等位基因频率水平，频率在 87%至 100%之间。在过表达的基因中，CYP6P4 基因在 LS、AS 和 LAS 组中过表达最为明显。-L995F 抗性蒂亚萨莱品系的幼虫和成虫长期接触溴氰菊酯和 PermaNet 2.0 蚊帐，在细胞色素 P450 解毒酶的显著作用下诱导了对溴氰菊酯的抗性。这些结果强调了在实施病媒控制策略之前，不仅要研究目标人群中的抗性机制，还要研究代谢抗性机制，以便获得更好的效果。
