Scholarlink

Background <p>Entomopathogenic fungi like <i>Metarhizium</i> are emerging as effective biopesticides against malaria vectors. They reduce mosquito survival, fecundity, and flight ability, and reverse insecticide susceptibility in resistant <i>Anopheles gambiae</i> sensu lato strains. To elucidate the unclear underlying mechanisms, this study investigates the effects of fungal infections and insecticide exposure on the mosquito’s energy reserves and the expression of key metabolic and immune genes.</p> Methods <p>Three mosquito types: (i) pyrethroid-resistant <i>An. gambiae</i> sensu lato and two laboratory colonies: (ii) pyrethroid-resistant <i>An. coluzzii</i> VKPER and (iii) insecticide-susceptible <i>An. gambiae</i> sensu stricto Kisumu were used. They were infected with <i>Metarhizium pingshaense</i> S10 strain at a concentration of 10⁷&#xa0;spores/mL (treatment groups) and with solvent only (0.05% Tween<sup>®</sup> 80; control groups). Live mosquitoes were collected on days 0, 4, and 8 post-infection. They were used to quantify glucose, glycogen, and lipid via Van Handel’s protocol and to assess insecticide resistance. For resistance testing, mosquitoes underwent a standard WHO insecticide susceptibility test using deltamethrin (0.05%) or a control. Survival was measured 1&#xa0;h after exposure, and surviving mosquitoes were analyzed by RT-qPCR for the expression of <i>defensin</i> and <i>CYP6P3</i>, <i>CYP6Z1</i>, and <i>GSTe2</i>.</p> Results <p>Susceptible <i>An. gambiae</i> Kisumu were eliminated by deltamethrin, while resistant <i>An. coluzzii</i> VKPER and wild <i>An. gambiae</i> s.l. mosquitoes survived. However, deltamethrin exposure following <i>Metarhizium</i> infection significantly reduced survival in these resistant strains compared to the controls. This also resulted in reduced expression levels of <i>defensin</i>, <i>GSTe2</i>, and <i>CYP6Z1</i> compared to deltamethrin exposure alone, but no difference was found in the expression levels of <i>CYP6P3</i>. These results collectively indicate that <i>Metarhizium</i> infection reduces mosquito survival by impairing their energetic reserves and ability to sustain vital physiological processes, including immune function and metabolic homeostasis.</p> Conclusions <p>We demonstrate that <i>Metarhizium</i> infection reverses insecticide resistance in <i>An. gambiae</i> s.l. by depleting energy reserves and suppressing the expression of detoxification genes. This mechanistic insight is crucial for optimizing the future integration of <i>Metarhizium</i> alongside conventional insecticides for malaria vector control.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Metarhizium pingshaense infection reverses insecticide resistance in Anopheles gambiae sensu lato by altering energy reserves and gene expression

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年11月28日

查看全文
  • Doubé Lucien Lamy,
  • Francesco Baldini,
  • Mafalda Viana,
  • Iván Casas Gómez-Uribarri,
  • Duangkamon Loesbanluechai,
  • Erin S. Johnston,
  • Meshach Lee,
  • Najat Feruzi Kahamba,
  • Edounou Jacques Gnambani,
  • Issiaka Saré,
  • Souro Abel Millogo,
  • Moussa Namountougou,
  • Abdoulaye Diabaté,
  • Etienne Bilgo

摘要

Background

Entomopathogenic fungi like Metarhizium are emerging as effective biopesticides against malaria vectors. They reduce mosquito survival, fecundity, and flight ability, and reverse insecticide susceptibility in resistant Anopheles gambiae sensu lato strains. To elucidate the unclear underlying mechanisms, this study investigates the effects of fungal infections and insecticide exposure on the mosquito’s energy reserves and the expression of key metabolic and immune genes.

Methods

Three mosquito types: (i) pyrethroid-resistant An. gambiae sensu lato and two laboratory colonies: (ii) pyrethroid-resistant An. coluzzii VKPER and (iii) insecticide-susceptible An. gambiae sensu stricto Kisumu were used. They were infected with Metarhizium pingshaense S10 strain at a concentration of 10⁷ spores/mL (treatment groups) and with solvent only (0.05% Tween® 80; control groups). Live mosquitoes were collected on days 0, 4, and 8 post-infection. They were used to quantify glucose, glycogen, and lipid via Van Handel’s protocol and to assess insecticide resistance. For resistance testing, mosquitoes underwent a standard WHO insecticide susceptibility test using deltamethrin (0.05%) or a control. Survival was measured 1 h after exposure, and surviving mosquitoes were analyzed by RT-qPCR for the expression of defensin and CYP6P3, CYP6Z1, and GSTe2.

Results

Susceptible An. gambiae Kisumu were eliminated by deltamethrin, while resistant An. coluzzii VKPER and wild An. gambiae s.l. mosquitoes survived. However, deltamethrin exposure following Metarhizium infection significantly reduced survival in these resistant strains compared to the controls. This also resulted in reduced expression levels of defensin, GSTe2, and CYP6Z1 compared to deltamethrin exposure alone, but no difference was found in the expression levels of CYP6P3. These results collectively indicate that Metarhizium infection reduces mosquito survival by impairing their energetic reserves and ability to sustain vital physiological processes, including immune function and metabolic homeostasis.

Conclusions

We demonstrate that Metarhizium infection reverses insecticide resistance in An. gambiae s.l. by depleting energy reserves and suppressing the expression of detoxification genes. This mechanistic insight is crucial for optimizing the future integration of Metarhizium alongside conventional insecticides for malaria vector control.

Graphical Abstract