摘要

      环境中的微塑性污染正受到全世界的关注；然而，抗生素和微塑性污染对全球分布和功能上重要的非目标土壤动物肠道菌群的影响仍然知之甚少。我们研究了一种模式的弹尾虫（Folsomia candida），发现摄入微塑料（聚苯乙烯，2-2.9μm）可显著改变土壤弹尾虫组织中的肠道微生物群、抗生素抗性基因（ARG）谱和同位素分馏。重要的是，与单独暴露于聚苯乙烯（MH）的人相比，暴露于含有磺胺甲恶唑（MA）的聚苯乙烯微塑料的人呈现出独特的肠道微生物群、ARG分布和同位素分馏。我们观察到，MA处理的弹尾目动物内脏中的精氨酸和移动遗传元素（MGE）含量显著高于MH和对照组。在弹尾目动物肠道中，肠道微生物群与ARGs之间也有较强的相互作用。我们进一步发现，在弹尾类人体组织中，细菌β-多样性与δ13C和δ15N值显著相关。我们的研究结果表明，弹尾目动物的同位素分馏和ARG剖面的变化是由肠道微生物群的变化引起的，表明不同来源的微塑料可能对土壤动物和土壤食物网产生深远的影响。

      Microplastics pollution in the environment is now receiving worldwide attention; however, the effects of copollution of antibiotics and microplastics on the gut microbiome of globally distributed and functionally important nontarget soil animals remain poorly understood. We studied a model collembolan (Folsomia candida) and found that the ingestion of microplastics (polystyrene, 2-2.9 μm) substantially altered the gut microbiome, antibiotic resistance gene (ARG) profile, and the isotopic fractionation in the soil collembolan tissue. Importantly, collembolans exposed to polystyrene microplastics loaded with sulfamethoxazole (MA) presented a distinctive gut microbiome, ARG profile, and isotopic fractionation compared to those exposed to polystyrene alone (MH). We observed that the abundance of ARGs and mobile genetic elements (MGEs) in the MA-treated collembolan guts was significantly higher than in the MH and the control treatments. There were also strong interactions between the gut microbiome and ARGs in the collembolan guts. We further found that bacterial β-diversity correlated significantly with the δ¹³C and δ¹⁵N values in collembolan body tissues. Together, our results indicate that changes in isotopic fractionation and ARG profiles in the collembolan were induced by the changes in gut microbiota and suggest that microplastics from diverse sources may have profound influences on soil fauna and soil food webs.

      https://pubs.acs.org/doi/10.1021/acs.est.9b04795