摘要

    越来越多的证据表明，微塑料可以吸附抗生素，因此可能加剧对裸露生物健康的影响。目前我们对土壤中无脊椎动物中抗生素和抗微生物基因（ARGs）的组合作用的了解是有限的。这项研究的目的是调查暴露于含有微塑料和抗生素的土壤环境后，隐球菌的微生物组和ARGs的变化。四环素（TC），聚酰胺（PA）和聚氯乙烯（PVC）用于构建污染土壤环境（TC，PA，PVC，PA + TC，PVC + TC）的缩影。微生物组和ARGs的差异通过细菌16S rRNA基因扩增子测序和高通量定量PCR确定。结果表明，与对照或单独使用微塑料的处理相比，单独或与微塑料组合使用时，隐孢子虫中TC的积累显着（P <0.05），但TC，PA之间的TC积累没有显着差异。 + TC和PVC + TC处理的隐孢子虫（P> 0.05）。微生物和TC显着干扰了微生物群落，并降低了隐孢大肠杆菌的微生物α多样性（P <0.05）。然而，TC，微塑料及其组合暴露处理之间没有显着差异，并且在土壤环境中四环素和微塑料之间的隐孢子虫微生物组多样性没有毒性协同作用。所有的处理都增加了隐孢子虫的ARGs的多样性（39-49 ARGs vs. 25 ARGs）。特别是，与将隐孢子虫单独暴露于PVC，PA或TC时相比，将PVC和TC或PA和TC暴露相结合的处理导致更大的ARGs丰度。这些结果加深了我们对微生物和抗生素对无脊椎动物ARGs和微生物组的联合作用的理解。

    Growing evidence suggests that microplastics can adsorb antibiotics and may consequently exacerbate effects on the health of exposed organisms. Our current understanding of the combined effects of microplastics and antibiotics on antibiotic resistance genes (ARGs) in soil invertebrates is limited. This study aimed to investigate changes in the microbiome and ARGs in Enchytraeus crypticus following exposure to a soil environment that contained both microplastics and antibiotics. Tetracycline (TC), polyamide (PA) and polyvinyl chloride (PVC) were used to construct microcosms of polluted soil environments (TC, PA, PVC, PA+TC, PVC+TC). The differences in microbiomes and ARGs were determined by bacterial 16S rRNA gene amplicon sequencing and high throughput quantitative PCR. The results show that compared with the Control or microplastics alone treatments, TC was significantly accumulated in E. crypticus when exposed to TC alone or in combination with microplastics (P < 0.05), but there were no significant differences about TC accumulation between TC, PA+TC, and PVC+TC treated E. crypticus (P > 0.05). Microplastics and TC significantly disturbed the microbial community, and decreased the microbial alpha diversity of E. crypticus (P < 0.05). However, there were no significant differences between TC, microplastics and their combined exposure treatments, and no toxic synergies on the diversity of E. crypticus microbiome between tetracycline and microplastics in soil environment. All the treatments increased the diversity of ARGs in E. crypticus (39–49 ARGs vs. 25 ARGs of control). In particular, treatments combining PVC and TC or PA and TC exposure resulted in greater ARGs abundance than the treatments when E. crypticus was exposed to PVC, PA or TC alone. These results add to our understanding of the combined effects of microplastics and antibiotics on the ARGs and microbiome of soil invertebrates.

    https://www.sciencedirect.com/science/article/abs/pii/S026974912030289X