Yeast encapsulation of photosensitive insecticides increases toxicity against mosquito larvae while protecting microorganisms

• Published in: PloS one 2024-10, Vol.19 (10), p.e0310177
• Main Authors: Meier, Cole J, Wrobleski, Veronica R, Hillyer, Julián F
• Format: Article
• Language: English
• Subjects: Aluminum; Animals; Anopheles - drug effects; Anopheles gambiae; Aquatic insects; Biocompatibility; Biology and Life Sciences; Control; Curcumin; Curcumin - chemistry; Curcumin - pharmacology; E coli; Effectiveness; Encapsulation; Escherichia coli; Escherichia coli - drug effects; Ethanol; Evaluation; Ingestion; Insect control; Insecticide resistance; Insecticides; Insecticides - chemistry; Insecticides - pharmacology; Insecticides - toxicity; Larva - drug effects; Larvae; Larvicides; Light; Medicine and Health Sciences; Methylene blue; Methylene Blue - pharmacology; Microorganisms; Mosquito Control - methods; Mosquitoes; Oxidation resistance; Pesticide resistance; Photodegradation; Photosensitivity; Photosensitizing Agents - chemistry; Photosensitizing Agents - pharmacology; Phototoxicity; Physical Sciences; Research and Analysis Methods; Saccharomyces cerevisiae - drug effects; Testing; Toxic diseases; Toxicity; Water; Yeast; Yeast fungi; Yeasts
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0310177

An important defense against the deadly diseases that mosquitoes transmit is the application of insecticides that reduce mosquito populations. Unfortunately, the evolution and subsequent spread of insecticide resistance has decreased their efficacy. Therefore, new mosquito control strategies are needed. One class of larvicides, known as photosensitive insecticides, or PSIs, kills larvae via light-activated oxidative damage. PSIs are promising larvicides because of their high larvicidal efficacy, rapid photodegradation, inexpensive cost, and mechanism that is dissimilar to other insecticide classes. We explored a novel delivery strategy for increasing both the larvicidal efficiency and environmental biocompatibility of PSIs, known as yeast encapsulation. Using the PSIs, curcumin and methylene blue, we measured the survival of Anopheles gambiae larvae and Escherichia coli following exposure to either non-encapsulated or yeast-encapsulated PSIs and a photoperiod. Yeast encapsulation increased the phototoxicity of both curcumin and methylene blue against mosquito larvae, likely by increasing ingestion. Furthermore, yeast encapsulation protected E. coli from the phototoxicity of yeast-encapsulated curcumin, but not yeast-encapsulated methylene blue. Yeast encapsulation increases the larvicidal efficacy of a PSI while also increasing biocompatibility. Therefore, yeast encapsulation of PSIs is a promising insecticide delivery strategy for mosquito control.