Department of Biological Sciences, Texas Tech University, 2901 Main St., Lubbock, TX 79409, USA.
Department of Environmental Toxicology, Texas Tech University, 1207 S. Gilbert Drive, Lubbock, TX 79416, USA.
J Med Entomol. 2023 Sep 12;60(5):884-898. doi: 10.1093/jme/tjad097.
Microplastics (MPs) are common environmental pollutants; however, little is known about their effects after ingestion by insects. Here we fed Aedes (Stegomyia) aegypti (L.) and Aedes (Stegomyia) albopictus (Skuse) mosquito larvae 1 µm polystyrene MPs and examined the impacts of ingestion on adult emergence rates, gut damage, and fungal and bacterial microbiota. Results show that MPs accumulate in the larval guts, resulting in gut damage. However, little impact on adult emergence rates was observed. MPs are also found in adult guts postemergence from the pupal stage, and adults expel MPs in their frass after obtaining sugar meals. Moreover, MPs effects on insect microbiomes need to be better defined. To address this knowledge gap, we investigated the relationship between MP ingestion and the microbial communities in Ae. albopictus and Ae. aegypti. The microbiota composition was altered by the ingestion of increasing concentrations of MPs. Amplicon sequence variants (ASVs) that contributed to differences in the bacterial and fungal microbiota composition between MP treatments were from the genera Elizabethkingia and Aspergillus, respectively. Furthermore, a decrease in the alpha diversity of the fungal and bacterial microbiota was observed in treatments where larvae ingested MPs. These results highlight the potential for the bacterial and fungal constituents in the mosquito microbiome to respond differently to the ingestion of MPs. Based on our findings and the effects of MP ingestion on the mosquito host micro- and mycobiome, MP pollution could impact the vector competence of important mosquito-transmitted viruses and parasites that cause human and animal diseases.
微塑料（MPs）是常见的环境污染物；然而，人们对昆虫摄入微塑料后的影响知之甚少。在这里，我们给埃及伊蚊和白纹伊蚊的幼虫喂食了 1 µm 聚苯乙烯 MPs，并检查了摄入对成虫出蛹率、肠道损伤以及真菌和细菌微生物群的影响。结果表明，MPs 在幼虫肠道中积累，导致肠道损伤。然而，对成虫出蛹率的影响很小。在从蛹期出蛹后，MPs 也在成蚊肠道中被发现，并且成虫在获得糖餐后会在粪便中排出 MPs。此外，还需要更好地定义 MPs 对昆虫微生物组的影响。为了解决这一知识空白，我们研究了埃及伊蚊和埃及按蚊中 MPs 摄入与微生物群落之间的关系。摄入 MPs 会改变微生物群落的组成。导致细菌和真菌微生物群落组成在 MPs 处理之间存在差异的扩增子序列变异（ASVs）分别来自伊丽莎白菌属和曲霉属。此外，在幼虫摄入 MPs 的处理中，真菌和细菌微生物群落的 alpha 多样性下降。这些结果表明，蚊子微生物群中的细菌和真菌成分可能对 MPs 的摄入有不同的反应。基于我们的发现以及 MPs 摄入对蚊子宿主微生态和真菌组的影响，MP 污染可能会影响传播人类和动物疾病的重要蚊媒病毒和寄生虫的媒介能力。
