College of Science and Engineering, James Cook University, Townsville, Australia.
School of Natural Sciences Macquarie University, Sydney, Australia; ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, Australia.
Environ Pollut. 2023 Jun 15;327:121558. doi: 10.1016/j.envpol.2023.121558. Epub 2023 Apr 3.
Plastic pollution is a serious global problem, with more than 12 million tonnes of plastic waste entering the oceans every year. Plastic debris can have considerable impacts on microbial community structure and functions in marine environments, and has been associated with an enrichment in pathogenic bacteria and antimicrobial resistance (AMR) genes. However, our understanding of these impacts is largely restricted to microbial assemblages on plastic surfaces. It is therefore unclear whether these effects are driven by the surface properties of plastics, providing an additional niche for certain microbes residing in biofilms, and/or chemicals leached from plastics, the effects of which could extend to surrounding planktonic bacteria. Here, we examine the effects of polyvinyl chloride (PVC) plastic leachate exposure on the relative abundance of genes associated with bacterial pathogenicity and AMR within a seawater microcosm community. We show that PVC leachate, in the absence of plastic surfaces, drives an enrichment in AMR and virulence genes. In particular, leachate exposure significantly enriches AMR genes that confer multidrug, aminoglycoside and peptide antibiotic resistance. Additionally, enrichment of genes involved in the extracellular secretion of virulence proteins was observed among pathogens of marine organisms. This study provides the first evidence that chemicals leached from plastic particles alone can enrich genes related to microbial pathogenesis within a bacterial community, expanding our knowledge of the environmental impacts of plastic pollution with potential consequences for human and ecosystem health.
塑料污染是一个严重的全球性问题，每年有超过 1200 万吨塑料废物进入海洋。塑料碎片会对海洋环境中的微生物群落结构和功能产生重大影响，并与致病性细菌和抗生素耐药性（AMR）基因的富集有关。然而，我们对这些影响的理解在很大程度上仅限于塑料表面的微生物组合。因此，尚不清楚这些影响是由塑料的表面特性驱动的，为某些生活在生物膜中的微生物提供了一个额外的小生境，还是由塑料浸出的化学物质驱动的，其影响可能会扩展到周围的浮游细菌。在这里，我们研究了聚氯乙烯（PVC）塑料浸出物暴露对海水微宇宙群落中与细菌致病性和 AMR 相关的基因相对丰度的影响。我们表明，在没有塑料表面的情况下，PVC 浸出物会导致 AMR 和毒力基因的富集。特别是，浸出物暴露显著富集了赋予多药、氨基糖苷类和肽类抗生素耐药性的 AMR 基因。此外，还观察到海洋生物病原体中与细胞外分泌毒力蛋白相关的基因富集。这项研究首次提供了证据，证明单独从塑料颗粒中浸出的化学物质可以在细菌群落中富集与微生物发病机制相关的基因，扩展了我们对塑料污染环境影响的认识，这可能对人类和生态系统健康产生潜在影响。
