Plastics in the marine environment are reservoirs for antibiotic and metal resistance genes

Yuyi Yang,Guihua Liu,Wenjuan Song,Chen Ye,Hui Lin,Zan Li,Wenzhi Liu

doi:10.1016/j.envint.2018.11.061

Abstract

Plastics have been accumulated offshore and in the deep oceans at an unprecedented scale. Microbial communities have colonized the plastisphere, which has become a reservoir for both antibiotic and metal resistance genes (ARGs and MRGs). This is the first analysis of the diversity, abundance, and co-occurrence of ARGs and MRGs, and their relationships within the microbial community, using metagenomic data of plastic particles observed in the North Pacific Gyre obtained from the National Centre for Biotechnology Information Sequence Read Archive database. The abundance of ARGs and MRGs in microbial communities on the plastics were in the ranges 7.07 × 10−4–1.21 × 10−2 and 5.51 × 10−3–4.82 × 10−2 copies per 16S rRNA, respectively. Both the Shannon-Wiener indices and richness of ARGs and MRGs in plastics microbiota were significantly greater than those of ARGs and MRGs in seawater microbiota in the North Pacific Gyre via one-way analysis of variance. Multidrug resistance genes and multi-metal resistance genes were the main classes of genes detected in plastic microbiota. There were no significant differences in the abundance or diversity of ARGs and MRGs between macroplastics biota and microplastics biota, indicating that particle size had no effect on resistance genes. Procrustes analysis suggested that microbial community composition was the determining factor of the ARG profile but not for MRG. Some ARGs and MRGs had a higher incidence of non-random co-occurrence, suggesting that the co-effects of selection for antibiotic or metal resistance are important factors influencing the resistome of the microbiota on the plastic particles.

Highlights

Plastic pollution is of great concern in aquatic environments and is well-documented in seawater ecosystems which include the Mediterranean Sea, the southwestern Indian Ocean (Woodall et al 2014), the Bohai Sea (Zhang et al 2017), the Baltic Sea (Tamminga et al 2018), and the North Atlantic Ocean (Courtene-Jones et al 2017)
Microbial communities have colonized the plastisphere, which has become a reservoir for both antibiotic and metal resistance genes (ARGs and MRGs). This is the first analysis of the diversity, abundance, and co-occurrence of ARGs and MRGs, and their relationships within the microbial community, using metagenomic data of plastic particles observed in the North Pacific Gyre obtained from the National Centre for Biotechnology Information Sequence Read Archive database
There were no significant differences in the abundance or diversity of ARGs and MRGs between macroplastics biota and microplastics biota, indicating that particle size had no effect on resistance genes

Summary

Introduction

Plastic pollution is of great concern in aquatic environments and is well-documented in seawater ecosystems which include the Mediterranean Sea, the southwestern Indian Ocean (Woodall et al 2014), the Bohai Sea (Zhang et al 2017), the Baltic Sea (Tamminga et al 2018), and the North Atlantic Ocean (Courtene-Jones et al 2017). Concentrations of copper and zinc have been observed to increase significantly on both virgin polystyrene beads and aged polyvinyl chloride fragments in seawater (Brennecke et al 2016). Various organic pollutants, such as polycyclic aromatic hydrocarbons (Rochman et al 2013), polychlorinated biphenyls (Velzeboer et al 2014), and antibiotics (Li et al 2018a), can be adsorbed onto plastics. Several studies have investigated microbial community structures on the plastics in the marine environment (Bryant et al 2016; Oberbeckmann et al 2014). Microplastics have recently been found to influence the evolution of microbial communities and to increase the exchange of genes, including antibiotic

Methods

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Discussion

Conclusion